# Patent

## Title
Camera for creating a panoramic image

## Abstract

Methods and apparatus to create and display panoramic images on a mobile device are disclosed. Such a mobile device can be a mobile phone. Apparatus is provided to control the position of a lens in relation to a reference lens. Methods and apparatus are provided to generate multiple images that are combined into a panoramic image. A panoramic image may be a static image. It may also be a video image. A controller provides correct camera settings for different conditions. An image processor creates a panoramic image from the correct settings provided by the controller. A panoramic camera is applied in a computer gaming system.

## Background
STATEMENT OF RELATED CASES
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/106,025, filed Oct. 16, 2008, and of U.S. Provisional Patent Application Ser. No. 61/106,768, filed Oct. 20, 2008, which are both incorporated herein by reference in their entirety.


BACKGROUND OF THE INVENTION
The present invention relates to digital image devices. More specifically, it relates to a controller device in a digital camera, the camera being enabled by the controller to record at least two images and generate a single, optimally registered panoramic image from those at least two images.
Digital cameras are increasingly popular. The same applies to camera phones. The digital images taken by these devices use a digital sensor and a memory which can store data generated by the sensor. Data may represent a still image. Data may also represent a video image. Images may be viewed on the device. Images may also be transferred to an external device, either for viewing, for storage or for further processing.
Panoramic images are also very popular and have been created from the time of photographic film to the present day of digital imaging. A whole range of tools exists to combine two or more images from a scene into a single, combined, hopefully seamless panoramic image. This process of combining is called registering, stitching or mosaicing. An advantage of a panoramic image is to provide a view of a scene that is usually beyond what is usually possible with a common camera and having no or very little distortion.
The process of picture taking for creating a panoramic image is a process that has many different technologies, apparatus and methods. Very common is the method of taking a first picture with a single lens camera, followed by taking at least a second picture at a later time, and followed by stitching the pictures together. This method is not very user friendly or requires complex cameras or complex camera settings. Furthermore, this method may be troublesome for creating video images.
Cameras with multiple lenses are also known. These cameras should be easier to use. However, current implementations still require users to provide fairly involved manual settings.
Accordingly, novel and improved methods and apparatus are required for creating, recording, storing and playing of panoramic images.
SUMMARY OF THE INVENTION
One aspect of the present invention presents novel methods and systems for recording, processing storing and concurrent displaying of a plurality of images which may be video programs into a panoramic image.
In accordance with an aspect of the present invention, an apparatus is provided for generating a combined image from at least a first and a second image of a scene with a camera having at least a first lens being associated with a first image sensor for generating the first image and a second lens being associated with a second image sensor for generating the second image, comprising a memory, enabled to store and provide data related to a first setting of the second lens, the first setting of the second lens being associated with data related to a first setting of the first lens, a controller, applying data related to the first setting of the first lens for retrieving from the memory data related to the first setting of the second lens, the controller using the retrieved data for driving a mechanism related to the second lens to place the second lens in the first setting of the second lens.
In accordance with a further aspect of the present invention, an apparatus is provided, further comprising the memory having stored data defining a first area of the second image sensor which is associated with the first setting of the first lens, and the memory having stored data defining a first area of the first image sensor which is associated with the first setting of the first lens.
In accordance with yet a further aspect of the present invention, an apparatus is provided, further comprising a display which displays the combined image which is formed by merging of image data from the first area of the first image sensor and image data of the first area of the second image sensor.
In accordance with yet a further aspect of the present invention, an apparatus is provided, further comprising, the first area of the first image sensor being determined by a merge line; and a display which displays the combined image which is formed by merging of image data from the first area of the first image sensor and image data of the first area of the second image sensor along the merge line.
In accordance with yet a further aspect of the present invention, an apparatus is provided, wherein the data defining a first area of the second image sensor determines what image data stored in an image memory is read for further processing.
In accordance with yet a further aspect of the present invention, an apparatus is provided, wherein a setting of the second lens is one or more of the group consisting of focus, diaphragm, shutter speed, zoom and position related to the first lens.
In accordance with yet a further aspect of the present invention, an apparatus is provided, further comprising at least a third lens being associated with a third image sensor.
In accordance with yet a further aspect of the present invention, an apparatus is provided, wherein the first lens and second lens are part of a mobile phone.
In accordance with yet a further aspect of the present invention, an apparatus is provided, wherein the image is a video image.
In accordance with yet a further aspect of the present invention, an apparatus is provided, wherein the camera is part of a computer gaming system.
In accordance with another aspect of the present invention, a method is provided for creating a stitched panoramic image from at least a first and a second image of a scene with a camera having at least a first lens being associated with a first image sensor for generating the first image and a second lens being associated with a second image sensor for generating the second image, comprising setting the first lens in a first focus setting on the scene, associating a first focus setting of the second lens with the first focus setting of the first lens, storing data related to the first focus setting of the second lens in a memory, determining an alignment parameter related to an alignment of an area of the first image sensor with an area of the second image sensor, associating the alignment parameter with the first focus setting of the first lens, and storing the alignment parameter in the memory.
In accordance with yet another aspect of the present invention, a method is provided, further comprising placing the first lens in the first focus setting, retrieving from the memory data of a focus setting of the second lens by applying the first setting of the first lens, and driving a mechanism of the second lens under control of a controller to place the second lens in a position using the retrieved data of the focus setting of the second lens.
In accordance with yet another aspect of the present invention, a method is provided, further comprising retrieving from the memory the alignment parameter related to the focus setting of the first lens, and generating the stitched panoramic image by processing image data generated by the first image sensor and the second image sensor in accordance with the alignment parameter related to the focus setting of the first lens.
In accordance with yet another aspect of the present invention, a method is provided, wherein the camera is part of a mobile computing device.
In accordance with a further aspect of the present invention, a controller is provided for generating a stitched panoramic image from at least two images of a scene with a camera having at least a first and a second lens and a first and a second image sensor, comprising a memory, enabled to store and retrieve data related to a setting of a first lens, a processor, enabled to retrieve data from the memory and the processor executing instructions for performing the steps of retrieving from the memory data determining a first setting of the second lens based on a first setting of the first lens, and instructing a mechanism related to the second lens to place the second lens in a setting determined by the retrieved data related to the first setting of the first lens.
In accordance with yet a further aspect of the present invention, a controller is provided, further comprising instructions to perform the steps of retrieving from the memory data defining an area of the first image sensor and data defining an area of the second image sensor related to the first setting of the first lens, and instructing an image processor to process image data of the area of the first image sensor and of the area of the second image sensor to create the stitched panoramic image.
In accordance with yet a further aspect of the present invention, a controller is provided, wherein a setting of a lens of the camera includes at least one of a group consisting of focus, aperture, exposure time, position and zoom.
In accordance with yet a further aspect of the present invention, a controller is provided, wherein the camera comprises a display for displaying the stitched panoramic image.
In accordance with yet a further aspect of the present invention, a controller is provided, wherein the camera is part of a gaming system.
In accordance with yet a further aspect of the present invention, a controller is provided, wherein the gaming system segments the stitched panoramic image from a background.
In accordance with yet a further aspect of the present invention, a controller is provided, wherein the image processor is enabled to blend image data based on the alignment parameter.



DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a camera for panoramic images in accordance with an aspect of the present invention;
FIG. 2 illustrates a panoramic image created in accordance with an aspect of the present invention;
FIG. 3 illustrates a panoramic image created in accordance with another aspect of the present invention;
FIG. 4 illustrates a panoramic image created in accordance with yet another aspect of the present invention;
FIG. 5 is a diagram of a camera for panoramic images in accordance with an aspect of the present invention;
FIG. 6 is a diagram of a camera for panoramic images in accordance with another aspect of the present invention;
FIG. 7 illustrates a panoramic image created in accordance with a further aspect of the present invention;
FIG. 8 illustrates a panoramic image created in accordance with yet a further aspect of the present invention;
FIG. 9 illustrates a panoramic image created in accordance with yet a further aspect of the present invention;
FIG. 10 is a diagram of a camera for panoramic images in accordance with another aspect of the present invention;
FIG. 11 is a diagram of a camera for panoramic images in accordance with yet another aspect of the present invention;
FIG. 12 is a diagram of a camera for panoramic images in accordance with yet another aspect of the present invention;
FIG. 13 is a diagram of a camera for panoramic images in accordance with yet another aspect of the present invention;
FIG. 14 is a diagram of a camera for panoramic images in accordance with yet another aspect of the present invention;
FIG. 15 is a diagram of a camera for panoramic images in accordance with yet another aspect of the present invention;
FIG. 16 illustrates a panoramic image created in accordance with a further aspect of the present invention;
FIG. 17 illustrates a panoramic image created in accordance with yet a further aspect of the present invention;
FIG. 18 is a diagram of a camera for panoramic images in accordance with yet another aspect of the present invention;
FIG. 19 is a diagram of a camera for panoramic images in accordance with yet another aspect of the present invention;
FIG. 20 is a diagram of a sensor/lens unit with moving mechanisms;
FIG. 21 is a diagram of another sensor/lens unit with moving mechanisms; and
FIG. 22 illustrates the storing of image data generated by two sensors.



DESCRIPTION OF A PREFERRED EMBODIMENT
In a first embodiment of the present invention, a camera is a digital camera with at least 2 lenses and each lens being associated with an image sensor, which may for instance be a CCD image sensor. It may also be a CMOS image sensor, or any other image sensor that can record and provide a digital image. An image sensor has individual pixel element sensors which generate electrical signals. The electrical signals can form an image. The image can be stored in a memory. An image stored in a memory has individual pixels, which may be processed by an image processor. An image recorded by a digital camera may be displayed on a display in the camera body. An image may also be provided as a signal to the external world, for further processing, storage or display. An image may be a single still image. An image may also be a series of images or frames, forming a video image when encoded and later decoded and displayed in appropriate form.
In one embodiment, to create a panoramic image a camera has at least two lenses, each lens being associated with an image sensor. This is shown in FIG. 1 in view 100 and 150. As an illustrative example a camera 100 has three lenses 101, 102 and 103. Each lens is associated with an image sensor. Accordingly, 101, 102 and 103 may also be interpreted as a sensor unit, which is an embodiment having a lens and an image sensor, the image sensor being able to provide image data or image signals to an image processor 111, which may store image data, which may have been processed, in a memory 114. The image generated by 111 may be displayed on a display 112. The image may also be provided on a camera output 104. In a further embodiment, image data as generated through a lens by a sensor may be stored in an individual memory, to be processed in a later stage.
The panoramic digital camera of FIG. 1 has, as an illustrative example, one central sensor unit with lens 102. Associated with this sensor unit is an autofocus sensor system 108. Autofocus systems for cameras are well known. The autofocus sensor system 108 senses the distance to an object that is recorded by sensor unit 102. It provides a signal to a motor or mechanism 106 that puts the lens of 102 in the correct focus position for the measured distance. In accordance with an aspect of the present invention, data that represents a position of the lens of 102 is stored in memory 110 and is associated with a signal or data generated by a measurement conducted by autofocus unit 108.
FIG. 1 provides two diagram views of the illustrative embodiment of a panoramic camera. View 100 is a top view. View 150 is a front view. It is to be understood that FIG. 1 only provides an illustrative example. Other configurations, with different orientation of lenses, different number of lenses, different autofocus units (for instance “through the lens”), different aspect ratios of the camera bodies, different viewer options in addition or in place of a display, control buttons, external connectors, covers, positioning of displays, shape of the body, a multi-part body wherein one part has the display and another part has the lenses, etc are all contemplated.
The autofocus system including sensor and mechanism may also include a driver or controller. Such drivers and controllers are known and will be assumed to be present, even if they are not mentioned. Autofocus may be one aspect of a lens/sensor setting. Other aspects may include settings of diaphragm and/or shutter speed based on light conditions and on required depth of field. Sensors, mechanisms and controllers and or drivers for such mechanisms are known and are assumed herein, even if not specifically mentioned.
A panoramic camera may be a self-contained and portable apparatus, with as its main or even only function to create and display panoramic images. The panoramic camera may also be part of another device, such as a mobile computing device, a mobile phone, a PDA, a camera phone, or any other device that can accommodate a panoramic camera.
Sensor units, motors, controller, memories and image processor as disclosed herein are required to be connected in a proper way. For instance, a communication bus may run between all components, with each component having the appropriate hardware to have an interface to a bus. Direct connections are also possible. Connecting components such as a controller to one or more actuators and memories is known. Connections are not drawn in the diagrams to limit complexity of the diagrams. However, all proper connections are contemplated and should be assumed. Certainly, when herein a connection is mentioned or one component being affected directly by another component is pointed out then such a connection is assumed to exist.
In order to generate a panoramic image in this illustrative example, three sensor units are used, each unit having a lens and each lens having a motor to put the lens in the correct focus position. The lens of image sensing unit 101 has a motor 105 and image sensor unit 103 has a motor 107. The motors may be piezoelectric motors, also called piezo motors. The field of view of the lens of unit 101 has an overlap with the field of view with the lens of unit 102. The field-of-view of the lens of unit 103 has an overlap with the field of view of the lens of unit 102. At least for the focus area wherein the field of view of lenses of 101, 102 and 103 have an overlap, the image processor 111 may register the three images and stitch or combine the registered images to one panoramic image.
The motors 105 and 107 may have limited degree of freedom, for instance, only movement to focus a lens. It may also include a zoom mechanism for a lens. It may also provide a lens to move along the body of the camera. It may also allow a lens to be rotated relative to the center lens.
Image registration or stitching or mosaicing, creating an integrated image or almost perfectly integrated image from two or more images is known. Image registration may include several steps including:
a. finding a region of overlap between two images which may include identifying corresponding landmarks in two images;
b. aligning two images in an optimally matching position;
c. transformation of pixels of at least one image to align corresponding pixels in two images; and
d. a blending or smoothing operation between two images that removes or diminishes between two aligned images a transition edge created by intensity differences of pixels in a connecting transition area.
The above steps for registering images are known and are for instance provided in Zitova, Barbara and Flusser, Jan: “Image registration methods: a survey” in Image and Vision Computing 21 (2003) pages 977-1000, which is incorporated herein by reference in its entirety. Another overview of registering techniques is provided in Image Alignment and Stitching: A Tutorial, by Richard Szeliski, Technical Report MSR-TR-2004-92, Microsoft, 2004, available on-line which is incorporated herein by reference.
The image processor may be enabled to perform several tasks related to creating a panoramic image. It may be enabled to find the exact points of overlap of images. It may be enabled to stitch images. It may be enabled to adjust the seam between two stitched images by for instance interpolation. It may also be able to adjust intensity of pixels in different images to make stitched images having a seamless transition.
It is possible that the three image lens/sensor units are not optimally positioned in relation to each other. For instance, the units may be shifted in a horizontal plane (pitch) in vertical direction. The sensor units may also be rotated (roll) related to each other. The sensor units may also show a horizontal shift (yaw) at different focus settings of the lenses. The image processor may be enabled to adjust images for these distortions and correct them to create one optimized panoramic image at a certain focus setting of the lens of unit 102.
At a certain nearby focus setting of the lenses it may no longer be possible to create a panoramic image of acceptable quality. For instance, parallax effects due to spacing of the lens units may be a cause. Also, the multiplier effect of lens and sensor systems (sizes) in digital cameras may limit the overlap in a sensor unit configuration as shown in FIG. 1. However, the configuration as shown in FIG. 1 is still able to create quality panoramic images in a digital camera, for instance in a camera phone. In a further embodiment of the present invention, the focus settings of the lenses of unit 101 and 103 by motors 105 and 107 are coordinated with the focus setting of the lens of unit 102 by motor 106 controlled by autofocus unit 108 by the controller 109.
In a further embodiment, motors or mechanisms moving the actual position of units 101 and 103 in relation to 103 may be used to achieve for instance a maximum usable sensor area of aligned sensors. These motors may be used to minimize image overlap if too much image overlap exists, or to create a minimum overlap of images if not enough overlap exists, or to create overlap in the right and/or desirable areas of the images generated by the sensors. All motor positions may be related to a reference lens position and focus and/or zoom factor setting of the reference lens. Motor or mechanism positions may be established and recorded in a memory in the camera during one or more calibration steps. A controller may drive motors or mechanism in a desired position based on data retrieved from the memory.
System Calibration
A coordination of sensor/lens units may be achieved in a calibration step. For instance, at one distance to an object the autofocus unit provides a signal and/or data that creates a first focus setting by motor 106 of the lens of 102, for instance, by using controller 109. This focus setting is stored in a memory 110. One may next focus the lens of unit 101 on the scene that contains the object on which the lens of 102 is now focused. One then determines the setting or instructions to motor 105 that will put the lens of unit 101 in the correct focus. Instructions related to this setting are associated with the setting of the lens of 102 and are stored in the memory 110. The same step is applied to the focus setting of the lens of unit 103 and the motor 107. Thus, when the sensor unit 108 creates a focus of the lens of 102, settings related to the lenses of 101 and 103 are retrieved from memory by a controller 111 from memory 110. The controller 111 then instructs the motors 105 and 107 to put the lenses of units 101 and 103 in the correct focus setting corresponding to a focus setting of the lens of unit 101, in order for the image processor 111 to create an optimal panoramic image from data provided by the image sensor units 101, 102 and 103.
One then applies the above steps for other object distances, thus creating a range of stored settings that coordinates the settings of the lenses of multiple sensor units. One may have a discrete number of distance settings stored in memory 110. One may provide an interpolation program that allows controller 109 to determine intermediate settings from settings that are stored in memory 110.
One may store positions and settings as actual positions or as positions to a reference setting. One may also code a setting into a code which may be stored and retrieved and which can be decoded using for instance a reference table. One may also establish a relationship between a setting of a reference lens and the setting of a related lens and have a processor determine that setting based on the setting of the reference lens.
In a further embodiment, one may combine focus setting with aperture settings and/or shutter speed for different hyperfocal distance settings. One may have different hyperfocal settings which may be selected by a user. If such a setting is selected for one lens, the controller 111 may apply these settings automatically to the other lenses by using settings or instructions retrieved from memory 110. A camera may automatically use the best hyperfocal setting, based on measured light intensity.
In general, camera users may prefer a point-and-click camera. This means that a user would like to apply as few manual settings as possible to create a picture or a video. The above configuration allows a user to point a lens at an object or scene and have a camera controller automatically configure lens settings for panoramic image creation.
In general, image processing may be processor intensive. This may be of somewhat less importance for creating still images. Creation of panoramic video that can be viewed almost at the same time that images are recorded requires real-time image processing. With less powerful processors it is not recommended to have software find for instance stitching areas, amount of yaw, pitch and roll, register images and so on. It would be helpful that the controller already knows what to do on what data, rather than having to search for it.
In a further embodiment of the present invention, instructions are provided by the controller 109 to image processor 111, based on settings of a lens, for instance on the setting of the center lens. These settings may be established during one or more calibration steps. For instance, during a calibration step in applying a specific distance one may apply predefined scenes, which may contain preset lines and marks.
Different configurations of a multi-lens/multi-sensor camera and manufacturing processes for such a multi-lens/multi-sensor camera are possible. One configuration may have motors to change lateral position and/or rotational position of a sensor/lens unit in relation to the body of the camera. This may lead to a camera with a broader range of creating possible panoramic images. It may also alleviate required processing power for an image processor. The use of such motors may also make the tolerances less restrictive of positioning sensor/lens units with regard to each other. This may make the manufacturing process of a camera cheaper, though it may require more expensive components, including motors or moving mechanisms.
In a further embodiment, one may position the sensor/lens units in exactly a preferred fixed position of each other, so that no adjustments are required. Such a construction may put severe requirements on the accuracy of manufacturing, thus making it relatively expensive.
In yet a further embodiment, one may allow some variation in rotation and translation in positioning the sensor/lens units, thus making the manufacturing process less restrictive and potentially cheaper. Any variation of positioning of sensors may be adjusted by the image processors, which may be assisted by calibration steps. In general, over time, signal processing by a processor may be cheaper than applying additional components such as motors, as cost of processing continues to go down.
A first calibration step for a first illustrative embodiment of a set of 3 sensor units is described next. Herein, a set of three sensor/lens units is considered to be one unit. It is manufactured in such a way that three lenses and their sensors are aligned. The image created by each sensor has sufficient overlap so that at a maximum object distance and a defined minimum object distance a panoramic image can be created. A diagram is shown in FIGS. 2 and 3. In FIG. 2 a scene 200 provides a plurality of calibration points. One may relate images generated by the camera of FIG. 1 to images shown in FIGS. 2, 3 and 4. The image recorded by sensor/lens 102 in FIG. 1 is shown as window 203 in FIG. 2. This image will be used as the reference window in the examples. Other references are also possible. As one views an image in mirror in relation to the sensor/lens unit, the window 205 is related to sensor/lens 101. The window 201 is related to sensor/lens 103.
The sensor/lens units are aligned so that aligned and overlapping windows are created. In FIG. 2 the windows and thus the sensors have no rotation and/or translation in reference to each other. At a first calibration test it is determined that sensor areas 202, 204 and 206 will create an optimal panoramic image at that distance. The setting being associated with a focus setting of the center sensor/lens unit 102, and with this setting being associated focus settings of lenses of 101 and 103 corresponding to the setting of 102, relevant settings being stored in a memory 110 that can be accessed by a controller 109. It may be that at this setting lens distortion is avoided or minimized by selecting image windows 202, 204 and 206 of the sensor area. One may determine the coordinates of each image area in a sensor and store these coordinates for instance also in memory 110. When the present focus setting is applied the image processor 111 is instructed by the controller 109 to only process the image within retrieved coordinates of the image sensor which are associated with the setting in memory 110. One may provide a certain margin to allow the image processor to determine an optimal overlap with a very narrow margin. This limits the load on the processor and allows the image processor, based on predetermined settings to quickly create a stitched panoramic image.
When windows 201, 203 and 205 related to the image sensors are aligned it may suffice to establish a merge line 210 and 211 between the windows. In that case, one may instruct a processor to apply the image data of window/sensor 201 left of the merge line 210, use the image data of window/sensor 203 between merge lines 210 and 211 and the image data of window/sensor 205 to the right of merge line 211. One may save merge lines that are established during calibration as a setting. One may process the data in different ways to establish a panoramic image. One may save the complete images and process these later according to established merge lines. One may also only save the image data in accordance with the merge lines. One may for instance, save the data in accordance with the merge line in a memory, so that one can read the data as a registered image.
It is noted that one may provide the images for display on an external device, or for viewing on a display that is part of the camera. Currently, image sensors may have over 2 Megapixels. That means that a registered image may have well over 5 Megapixels. Displays in a camera are fairly small and may be able to handle much smaller number of pixels. In accordance with a further aspect of the present invention, the recorded images are downsampled for display on a display in a camera.
One may repeat the above calibration steps at a different distance. It may be that certain effects influence distortion and overlap. This is shown in FIG. 3 as sensor windows 301, 303 and 305. Again sensor 102 of FIG. 1 may be the reference sensor. The effective overlap sensor areas for creating a panoramic image at the second distance may be sensor areas 302, 304 and 306 which may be different from sensor areas in FIG. 2. The coordinates of these sensor areas are again stored in a memory for instance 110 that is, for instance, accessible by the controller related to a focus setting. The area parameters in operation may be retrieved from 110 by controller 109 as being associated with a focus setting and provided by the controller 109 to the image processor 111 for creating a panoramic image from the sensor data based on the defined individual images related to a focus setting. Instead of saving a sensor area, one may also determine again a merge line that determines what the active area of a sensor should be. As an example, merge lines 310 and 311 are provided. It is noted that the merge lines are drawn as straight lines perpendicular to the base of a rectangular window. However, such a limitation is not required. First of all, a sensor does not need to be rectangular, and the active window of a sensor is also not required to be rectangular. Furthermore, a merge line may have any orientation and any curved shape.
One may repeat the steps for different distances and also for different lighting and image depth conditions and record focus setting and aperture setting and shutter setting and related sensor area parameters and/or merge lines in a memory. Such a system allows a camera to provide point-and-click capabilities for generating panoramic images from 2 or more individual images using a camera with at least two sensor/lens units.
In a further embodiment, one may be less accurate with the relative position of sensor/lens units in relation to the central unit. For instance, a sensor/lens 101 may have a vertical shift of translation to a reference unit 102 as is shown in FIG. 4. Herein, window 405 has a lateral shift relative to window 403. Furthermore, sensor/lens 103 may be rotated relative to 102. This is shown as a rotated window 401. It should be clear that a window may have a rotational deviation and a vertical and horizontal deviation. These deviations may be corrected by an image processor. It is important that the sensor/lens units are positioned so that sufficient overlap of images in effective sensor areas can be achieved, with minimal distortion. This is shown in FIG. 4. At a certain distance, related to a focus setting of the sensor/lens 102 sensor areas 402, 404 and 406 are determined to be appropriate to generate a panoramic image from these images. One may then again store the coordinates of the effective sensor areas in a memory 110, related to a sensor/lens focus. These coordinates may be accessed by controller 109 and provided to the image processor 111 for processing the images. The processor may apply these coordinates directly. In a further embodiment, one may store a transformed image in a buffer applying rectangular axes.
In FIG. 4 to illustrate the aspect of sensor area coordinates is illustrated by identified points 409, 410, 411 and 412, which identify the active sensor area to be used for the panoramic image. The rectangle determined by corners 409, 410, 411, 412 is rotated inside the axes of the image sensor 103 related to window 401. One may provide the image processor 109 with transformational instructions to create standard rectangular axes to refer to the pixels for processing. One may also write the data related to the pixels into a memory buffer that represents the pixels in standard rectangular axes. The coordinates also include the coordinates of the separation/merge line 407-408 between windows 401 and 403. One may also provide the coordinates of the separation line 415-416 between windows 403 and 405. The image processor may be instructed, for instance by the controller 109 which retrieves all the relevant coordinates from memory 110 based on a setting of a reference lens, to combine the active sensor area image of 407, 408, 410, 412 of sensor unit 103 with active sensor area 407, 408, 415, 416 of sensor unit 102. One should keep in mind that the coordinates of line 407-408 in sensor 102 may be different from the coordinates of line 407-408 in sensor 103 if one does not use standardized buffered images.
In a further embodiment, one may start calibration on a far distance scene, thus assuring that one can at least create a far distance scene panoramic image.
In yet a further embodiment, one may start calibration on a near distance scene, thus assuring that one can at least create a near distance scene panoramic image. In one embodiment, a near distance scene may be a scene on a distance from about 3 feet. In another embodiment, a near distance scene may be a scene on a distance from about 5 feet. In another embodiment, a near distance scene may be a scene on a distance from about 7 feet.
Near distance panoramic images, may for instance be an image of a person, for instance when the camera is turned so that 2 or more, or 3 or more sensor/lens units are oriented in a vertical direction. This enables the unexpected results of taking a full body picture of a person, who is standing no further than 3 feet, or no further than 5 feet, or no further than 7 feet from the camera.
In illustrative embodiments provided herein sensor/lens units with three lenses are provided. The embodiments generally provided herein will also apply to cameras with two lenses. The embodiments will generally also apply to cameras with more than three lenses. For instance, with 4 lenses, or to cameras with two rows of 3 lenses, or any configuration of lenses and/or sensor units that may use the methods that are disclosed herein. These embodiments are fully contemplated. FIG. 5 shows a diagram of an embodiment of a camera 500, which may be embodied in a camera phone, being a mobile computing device such as a mobile phone with a camera. This diagram shows 6 lenses in two rows. One row with lenses 501, 502 and 503, and a second row with lenses 504, 505 and 506. The camera also has at least an autofocus sensor 507 which will be able to assist a reference lens to focus. All lenses may be driven into focus by a focus mechanism that is controlled by a controller.
Motor Driven Calibration
In a further embodiment of a camera, one may provide a sensor/lens unit with one or more motors or mechanism, the motors or mechanism not being only for distance focus. Such a mechanism may provide a sensor/lens unit with the capability of for instance vertical (up and down) motion with regard to a reference sensor/lens unit. Such a motor may provide a sensor/lens unit with the capability of for instance horizontal (left and right) motion with regard to a reference sensor/lens unit. Such a motor may provide a sensor/lens unit with the capability of for instance rotational (clockwise and/or counterclockwise rotational motion) motion with regard to a reference sensor/lens unit. Such an embodiment is shown in FIG. 6. Rotational motion may turn the turned sensor/lens unit towards or away from a reference lens. Rotational motion may also rotate a sensor plane on an axis perpendicular to the sensor plane.
The camera of FIG. 6 is shown in diagram as 600. The camera has again 3 sensor/lens units as was shown in FIG. 1. These units are 601, 602 and 603. Unit 602 may be considered to be the reference unit in this example. It has a autofocus unit 608 associated with it. Each lens can be positioned in a correct focus position by a mechanism or a motor such as a piezo-motor. The system may work in a similar way as shown in FIG. 1. The camera may be pointed at an object at a certain distance. Autofocus unit 608 helps lens of unit 602 focus. Data associated with the distance is stored in a memory 610 that is accessible by a controller 609. Associated with this setting are the related focus settings of lenses of 601 and 603. Thus, a setting of the lens of 602 will be associated with a focus setting of 601 and 603 which will be retrieved from memory 610 by controller 609 to put the lenses of 601 and 603 in the correct focus position. An image processor 611 will process the images provided by sensor units 601, 602 and 603 into a panoramic image, which may be displayed on display 612. The panoramic image may be stored in a memory 614. It may also be provided on an output 604.
The sensor unit 601 may be provided with a motor unit or a mechanism 605 that is able to provide the sensor unit with a translation in a plane, for instance the sensor plane. The motor unit 605 may also have a rotational motor that provides clockwise and counterclockwise rotation to the sensor unit in a plane that may be the plane of the sensor and/or that may be in a plane not being in the sensor plane, so that the sensor unit 601 may be rotated, for instance, towards or away from unit 602. Sensor unit 603 has a similar motor unit or mechanism 606. Sensor unit 602 is in this example a reference unit and has in this case no motor unit for translational and rotational movements; however, it has a focus mechanism. Each unit of course has a focus motor for each lens. These motors are not shown in FIG. 6 but may be assumed and are shown in FIG. 1.
The calibration steps with the camera as provided in diagram in FIG. 6 work fairly similar to the above described method. One will start at a certain distance and lighting conditions and with unit 608 have a focus setting determined for 602 which will be associated with a focus setting for units 601 and 603 and which will be stored in memory 610 to be used by controller 609. Assume that the sensor units are not perfectly aligned for creating an optimal panoramic image. The sensor unit 601, 602 and 603 show the images of 702, 700 and 701. For illustrative purposes, a space between the images is shown, the images thus having no overlap. This situation of no overlap may not occur in real life if for instance no zoom lenses are used. However, the method provided herein is able to address such a situation if it occurs and thus is shown.
As a next step the motor units 605 and 606 are instructed to align the windows 701 and 702 with 700. This is shown in FIG. 8. Herein, windows 801 and 802 created by the sensor units 603 and 601 which were adjusted in position by the motor units 606 and 605. It may be determined that sensor areas 804 and 805 need to be combined or registered with area 803 as shown in FIG. 8 to generate an optimal panoramic image by image processor 611, which may require a lateral movement of units 601 and 603 by mechanisms 605 and 606. Furthermore, it is determined that sensor areas 803, 804 and 805 provide the best panoramic image for the applied distance in a stitched and registered situation. The motor units are then instructed to put the sensor units 601 and 603 in the positions that provide the correct image overlap as shown in FIG. 9. This creates a panoramic image formed by image sensor areas 804, 803 and 805 touching at position 901 and 902 as shown in FIG. 9 and forming panoramic image 900. All motor instructions to achieve this setting are stored in memory 610 where it is associated with a focus setting determined by unit 608. Furthermore, also stored in memory 610 are the coordinates of the respective sensor areas and the separation lines that will be retrieved by controller 609 and provided to image processor 611 to create an optimal panoramic image. These coordinates are also associated with a focus setting. As an illustrative example of the coordinates 903, 904 and 905 are shown as part of defining the active image sensor area of window 801. By knowing the active sensor areas per sensor including the separation lines, one may easily combine the different images into a stitched or panoramic image. If required, one may define a search area which can be very narrow to optimize stitching and to correct for any alignments inaccuracies by the image processor.
One can repeat the calibration setting for different distances. There may be a difference in field of view between images at difference distances for instance due to the digital multiplier of a sensor unit. Also, parallax may contribute to a need to adjust angles of the sensor/lens units 601 and 603. Zoom settings, of course, will also affect the field of view. It may be possible to align the sensor/lens units in one plane in the manufacturing phase without adjusting the relative position of sensor/lens units. It may still be beneficial to adjust the relative settings of the sensor/lens units. In such a case, the motors or mechanisms may for instance only be rotational motors.
For instance, zoom motors may be required in case the lenses are zoom lenses. In that case, the field of view changes with a changing zoom factor. Such a camera is shown in diagram in FIG. 10. The camera has the same elements as the camera shown in FIG. 6, including a distance focus motor for each lens that are not shown but are assumed. Furthermore, the camera of FIG. 10 has a zoom mechanism 1001 for sensor/lens unit 601, a zoom mechanism 1002 for sensor/lens unit 602, and a zoom mechanism 1003 for sensor/lens unit 603. Calibration of the camera of FIG. 10 works in a similar way as described earlier, with the added step of creating settings for one or more zoom settings per distance settings. A zoom mechanism may be controlled by a controller. A calibration step may work as follows: the lens of unit 602 is set in a particular zoom setting by zoom mechanism 1002. This zoom setting is stored in memory 610 and the lenses of units 601 and 603 are put in a corresponding zoom position with mechanisms 1001 and 1003. The instructions to units 1001 and 1003 to put lenses of 601 and 603 in their corresponding zoom positions are stored in memory 610 and associated with the zoom position of 602 affected by 1002. So, when the lens of 602 is zoomed into position, controller 609 automatically puts the lenses of 601 and 603 in corresponding positions by retrieving instructions from memory 610 and by instructing the motors of 1001 and 1003.
In a further embodiment, the mechanism of 1002 may contain a sensor which senses a zoom position. In such an embodiment, a user may zoom manually on an object thus causing the lenses of 601 and 603 also to zoom in a corresponding manner.
The combination of a distance with a zoom factor of unit 602, which is the reference unit in this example, determines the required position, zoom and focus of the units 601 and 602. As above, all instructions to achieve these positions for 601 and 603 are associated with the corresponding position of the reference unit 602 and stored in memory 610 which is accessible to controller 609. Included in the stored instructions may be the coordinates of the actively used sensor areas, which will be provided to image processor 611 to process the appropriate data generated by the sensors into a stitched and panoramic image as was provided earlier above.
As a consequence of creating a panoramic image of several images one may have created an image of considerable pixel size. This may be beneficial if one wants to display the panoramic image on a very large display or on multiple displays. In general, if one displays the panoramic image on a common display, or for instance on the camera display such high resolution images are not required and the processor 611 may have an unnecessary workload, in relation to what is required by the display. In one embodiment, one may want to provide the controller 609 with the capability to calculate the complete area of the panoramic image and the related pixel count. The controller 609 may have access to the pixel density that is required by a display, which may be stored in a memory 610 or may be provided to the camera. Based on this information the controller may provide the image processor with a down-sampling factor, whereby the images to be processed may be downsampled to a lower pixel density and the image processor can process images in a faster way on a reduced number of pixels. Such a downsizing may be manually confirmed by a user by selecting a display mode. Ultimate display on a large high-quality HD display may still require high pixel count processing. If, for instance, a user decides to review the panoramic image as a video only on the camera display, the user may decide to use a downsampling rate which increases the number of images that can be saved or increase the play time of panoramic video that can be stored in memory.
FIG. 11 shows an illustrative embodiment 1100 of a camera that can record at least 3 images concurrently of a scene from different perspectives or angles. The camera may provide a single multiplexed signal containing the three video signals recorded through 3 different lenses 1101, 1102 and 1103 and recorded on image sensors 1104, 1105 and 1106. The sensors are connected on a network which may be a bus controlled by bus controller 1110 and may store their signals on a storage medium or memory 1112 which is also connected to the network or bus. Further connected to the network is a controller 1111 with its own memory if required, which controls the motor units and may provide instructions to the image processor 1113. Also connected to the network are three motors units 1107, 1108 and 1109 for zooming and focusing lenses and moving lenses or lens units laterally or rotationally as required to put the lenses in one plane. Motor unit 1108 may only have zoom and focus capabilities in a further embodiment as lens unit 1102/1105 may be treated as the reference lens. The motors may be controlled by the controller 1111. Also connected to the network is an image processor 1113 with its own memory for instruction storage if required. Furthermore, the camera may have a control input 1114 for providing external control commands, which may include start recording, stop recording, focus and zoom commands. An input command may also include record only with center lens and sensor. An input command may also include record with all three lenses and sensors.
The camera also may have an output 1115 which provides a signal representing the instant image at one or all of the sensors. An output 1116 may be included to provide the data that was stored in the memory 1112. It should be clear that some of the outputs may be combined to fulfill the above functions. Furthermore, the camera may have additional features that are also common in single lens cameras, including a viewer and the like. A display 1118 may also be part of the camera. The display may be hinged at 119 to enable it to be rotated in a viewable position. The display is connected to the bus and is enabled to display the panoramic image which may be a video image. Additional features are also contemplated. The camera has at least the features and is enabled to be calibrated and apply methods as disclosed herein.
In a first embodiment, a user may select if images from a single lens or of all three lenses will be recorded. If the user selects recording images from all three lenses, then via the camera controller a control signal may be provided that focuses all three lenses on a scene. Calibrated software may be used to ensure that the three lenses and their control motors are focused correctly. In a further embodiment, the image signals are transmitted to the memory or data storage unit 1112 for storing the video or still images.
In yet a further embodiment, the signals from the three lenses may be first processed by the processor 1113 to be registered correctly into a potentially contiguous image formed by 3 images that can be displayed in a contiguous way. The processor in a further embodiment may form a registered image from 3 images that may be displayed on a single display.
The processor in yet a further embodiment may also process the images so that they are registered in a contiguous way if displayed, be it on one display or on three different displays.
In yet a further embodiment, the processor may register the three images and multiplex the signals so that they can be displayed concurrently on three different displays after being demultiplexed.
After being processed the processed signals from the sensors can be stored in storage/memory unit 1112. In yet a further embodiment, the signals are provided on an output 1115.
The reason for the different embodiment is the preference of a user for display and to make a camera potentially less complex and/or costly. One may, for instance, elect to make sure that all lenses and their controls are calibrated as to focus and/or zoom correctly. One may register images already in the camera through the processor 1113. However, one may also provide the three images either directly or from memory as parallel signals to a computing device such as a personal computer. The computing device may provide the possibility to select, for instance in a menu, the display of an image of a single lens/sensor. It may also provide a selection to display all three images in a registered fashion. The computing device may then have the means to register the images, store them in a contiguous fashion in a memory or a storage medium and play the images in a registered fashion either on one display or on three different displays.
For instance one may provide a signal available on output 1116, which may be a wireless or radio transmitter. Accordingly, a camera may make 3 or more video images, which may be multiplexed and registered or multiplexed and not registered available as a radio signal. Such radio signal may be received by a receiver and provided to a computing device that can process the signals to provide a registered image. A registered image may be provided on one display. It may also be provided on multiple displays.
There are different combinations in processing, multiplexing, registering, storing, outputting and displaying. One may elect to do most processing in the camera. One may also do the majority of the processing in the computing device and not in the camera. One may provide lens setting parameters with image data to facilitate processing by a computing device for processing and consequently displaying the registered images.
FIG. 12 shows a diagram of a camera for creating and displaying panoramic images by using 2 sensor/lens units 1201 and 1202 and having at least one autofocus unit 1203. Sensor/lens unit 1202 has at least a focus motor 1205 and sensor/lens unit 1201 has at least a focus motor 1206. The camera also has a controller 1209 which may have its separate memory 1210, which may be ROM memory. The camera also has an image processor 1211 which can process image data provided by sensor/lens units 1201 and 1202. A memory 1214 may store the panoramic images generated by the image processor. Motors may be controlled by the controller 1209, based in part on instructions or data retrieved from memory 1210 related to a setting of the autofocus unit 1203. Associated with a focus setting may be coordinates of sensor areas within sensors of units 1201 and 1202 of which the generated data will be processed by the image processor 1211. The controller 1209 may provide processor 1211 with the required limitations based on a focus setting. All settings may be determined during calibration steps as described earlier herein. A display 121 may be included to display the panoramic image. Signals related to a panoramic image may be provided on output 1204. In a further embodiment lens unit 1202 may be provided with a motor unit that can control lateral shifts and/or rotation of 1202 in relation to unit 1201. Settings of this motor unit may also be determined in a calibration setting. Diagram 1200 provides a top view and cross sectional view of the camera. Diagram 1250 provides a front view.
In one embodiment, a multi-lens camera is part of a mobile computing device, which may be a mobile phone or a Personal Digital Assistant (PDA) or a Blackberry® type of device, which may be provided with 2 or more or 3 or more lenses with related photo/video sensors which are calibrated to take a combined and registered image which may be a video image. A diagram is shown in FIG. 13 of a mobile computing device 1300 which may communicate in a wireless fashion with a network, for instance via an antenna 1304. While the antenna is shown it may also be hidden within the body. As an illustrative example the device has 3 lenses 1301, 1302 and 1303 which are enabled to record a scene in a way wherein the three individual images of the scene can be combined and registered into a wide view panoramic image, which may be a video image. The device has a capability to store the images in a memory. The device has a processor that can create a combined image. The combined image, which may be a static image such as a photograph or a video image can be stored in memory in the device. It may also be transmitted via the antenna 1304 or via a transmission port for output 1305 to an external device. The output 1305 may be a wired port for instance a USB output. It may also be a wireless output, for instance a Bluetooth output.
Viewing of the image may take place real-time on a screen 1403 of a device 1400 as shown in FIG. 14, which may be a different view of the device of FIG. 13. For instance, FIG. 13 may be a view of the device from the front and FIG. 14 from the back of the device. In FIG. 14 it is shown that the device is comprised of at least two parts 1400 and 1405, connected via a hinge system with connectors 1402 that allows the two bodies to be unfolded and body 1405 turned from facing inside to facing outside. Body 1400 may contains input controls such a keys. Body 1405 may contain a viewing display 1403. The lenses of FIG. 13 are on the outside of 1400 in FIG. 14 and not visible in the diagram. Body 1405 with screen 1403 may serve as a viewer when recording a panoramic image with the lenses. It may also be used for viewing recorded images that are being played on the device. The device of FIG. 14 may also receive via a wireless connection an image that was transmitted by an external device. Furthermore, the device of FIG. 14 may also have the port 1405 that may serve as an input port for receiving image data for display on display screen 1403.
In one embodiment, one may assume that the surface of the device as shown in FIG. 13 is substantially flat. In that case, the camera lenses 1301, 1302 and 1303 have a combined maximum field of view of 180 degrees. This may be sufficient for cameras with 3 lenses wherein each lens has a maximum field-of-vision of 60 degrees. In a further embodiment, one may have more than 3 lenses, enabling a combined field-of-vision of more than 180 degrees, or the field of view of the lenses adds up to more than 180 degrees. In such a further embodiment, the surface may be curved or angled, allowing 3 or more lenses to have a combined field-of-view of greater than 180 degrees.
A camera on a mobile phone is often considered a low cost accessory. Accordingly, one may prefer a multi-lens camera that will create panorama type images (either photographs and/or video) at the lowest possible cost. In such a low cost embodiment one may, for instance, apply only a two lens camera. This is shown in diagram in FIG. 15 with camera phone 1500 with lenses 1501 and 1502. In diagram in FIG. 16 it is shown how scenes are seen by the lenses. Lens 1501 ‘sees’ scene 1602 and lens 1502 ‘sees’ scene 1601. It is clear that the two sensor/lens units are not well oriented in regard to each other. As was described earlier above one may calibrate the camera to achieve an optimal and aligned panoramic image by good calibration. A processor in the camera may stitch the images together, based on control input by a calibrated controller. From a calibration it may be decided that lines 1603 and 1604 are merge lines which may be applied to image data. This again allows created registering of images without having to search for a point of registration. The ‘stitching’ may be as simple as just putting defined parts of the images together. Some edge processing may be required to remove the edge between images if it's visible. In general, the outside of an image may suffer from lens distortion.
FIG. 17 shows then the registered and combined image 1700. The image may be a photograph. It may also be a video image.
The embodiment as provided in FIG. 15 and its result shown in FIG. 17 is unusual in at least one sense that it creates a center of an image by using the edges of the images created by two lenses. In general, as in some aspects of the present invention, one assigns one lens to the center and presumably an important part of the image. The above embodiment allows for creating a good quality image by using inexpensive components and adjusting the quality of a combined image by a set of instructions in a processor. Except for a focus mechanism not other motors are required. Thus, relatively inexpensive components, few moving parts and a calibrated controller and an image processor with memory provide a desirable consumer article. Prices of electronic components go down while their performance constantly increases. Accordingly, one may create the above camera also in a manufacturing environment that not applies expensive manufacturing tolerances on the manufacturing process. Deviations in manufacturing can be off-set by electronics performance.
The methods provided herein may create a panoramic image that makes optimal use of available image sensor area. In some cases, this may create panoramic images that are not conforming to standard image sizes. One may as a further embodiment of the present invention implement a program in a controller that will create a panoramic image of a predefined size. Such a program may take actual sensor size and pixel density to fit a combined image into a preset format. In order to achieve a preferred size it may cause to lose image area. One may provide more image size options by for instance using two rows of sensor/lens units as for instance shown in FIG. 5 with two rows of 3 image sensors/lenses, or as shown in FIG. 18 by using two rows of 2 image sensors/lenses. Especially if one wants to print panoramic images on standard size photographic paper one may try to create an image that has a standard size, or that conforms in pixel count with at least one dimension of photographic print material.
In a further embodiment of the present invention one may adjust the size of an image sensor to allow creating standard size images or at least with one dimension such as the vertical dimension in a standard size and standard quality or higher.
Panoramic image cameras will become very affordable as prices of image sensors continue to fall over the coming years. By applying the methods disclosed herein one can create panoramic cameras with inexpensive sensors and electronics, having an excess of sensor area and/or lenses substitute for a need for motors, mechanisms and mechanical drivers.
It is to be understood that deviations of placement of sensors in the drawings herein may have been greatly exaggerated. It is to be expected that mis-alignment of sensors can be limited to about 1 mm or less. That may still represent a significant amount of pixels. Rotational positioning deviations may be less than about 2 degrees or 1 degree. That may still require significant sensor area adjustment. For instance, with a sensor having 3000×2000 pixels at a rotation of 1 degree without a lateral shift may have a shift of pixels of about 50 pixels in an y direction and a shift of 1 pixel in an x direction. Clearly, such a deviation requires a correction. However, the required mechanical adjustment in distance may well be within the limits of for instance piezo-motors. For larger adjustments other types of known motors may be applied. It also clear that though shifts of 50 pixels or even higher are unwanted, they still leave significant sensor area for usable image.
Due to the multiplier effect of the image sensor, zoom effects and other effects related to lens, lens position, image sensors and lighting conditions and the like one may have different lens settings of the lenses related to a reference lens. It is clearly the easiest to generate as may different conditions and settings during calibration as possible and save those settings with the related image areas and further stitching and blending parameters in a memory. A certain setting under certain conditions of a reference will be associated with related settings such as focus, aperture, exposure time, lens position and zoom of the other lenses. These positions may also be directly related with the active areas and/or merge lines of image sensors to assist in automatically generating a combined panoramic image. This may include transformation parameters for an image processor to further stitch and/or blend the separate images into a panoramic image.
It should be clear that lens settings between two extreme settings, such as for instance close-up object, or far away object may be significant. It is also clear that there may be only a finite number of calibrated settings. One may provide an interpolation program that interpolates between two positions and settings. The images may be video images. One may move a camera, for instance to follow a moving object. One may provide instructions, via a controller for instance, to keep a reference lens in a predetermined setting, to make sure that when the object temporarily leaves the field of vision of the reference lens that settings are not changed.
In a further embodiment of the present invention, images in a static format, in a video format, in a combined and registered format and/or in an individual format may be stored on a storage medium or a memory that is able to store a symbol as a non-binary symbol able to assume one of 3 or more states, or one of 4 or more states.
A combined, also called panoramic image exists as a single image that can be processed as a complete image. It was shown above that a combined and registered image may be created in the camera or camera device, by a processor that resides in the camera or camera device. The combined image, which may be a video image, may be stored in a memory in the camera or camera device. It may be displayed on a display that is a part or integral part of the camera device and may be a part of the body of the camera device. The combined image may also be transmitted to an external display device. A panoramic image may also be created from data provided by a multi-sensor/lens camera to an external device such as a computer.
Currently, the processing power of processors, especially of DSPs or Digital Signal Processors is such that advanced image processing methods may be applied real-time on 2D images. One of such methods is image extraction or segmentation of an image from its background. Such methods are widely known in medical imaging and in photo editing software and in video surveillance. Methods for foreground/background segmentation are for instance described in U.S. Pat. No. 7,424,175 to Lipton et al., filed on Feb. 27, 2007; U.S. Pat. No. 7,123,745 to Lee issued on Oct. 17, 2006; U.S. Pat. No. 7,227,893 issued on Jun. 5, 2007, which are incorporated herein by reference in their entirety and in many more references. For instance, Adobe's Photoshop provides the magnetic lasso tool to segment an image from its background.
Current methods, which can be implemented and executed as software on a processor allows for a combined and registered image to be processed. For instance, such an image may be a person as an object. One may identify the person as an object that has to be segmented from a background. In one embodiment, one may train a segmentation system by identifying the person in a panoramic image as the to be segmented object. For instance, one may put the person in front of a white or substantially single color background and let the processor segment the person as the image. One may have the person assume different positions, such as sitting, moving arms, moving head, bending, walking, or any other position that is deemed to be useful.
In order to facilitate later tracking of the person by a camera, one may provide the person with easy to recognize and detectable marks at positions that will be learned by the segmentation software. These methods for segmentation and tracking are known. They may involve special reflective marks or special color bands around limbs and head. One may store the learned aspects and/or other elements such as statistical properties of a panoramic object such as a person in a memory and which can be applied by a processor to recognize, detect, segment and/or track a person with a multi-sensor/lens video camera. In one embodiment, a system detects, tracks and segments the person as an object from a background and buffers the segmented image in a memory, which may be a buffer memory.
In one embodiment, one may insert the segmented object, which may be a person, in a display of a computer game. The computer game may be part of a computer system, having a processor, one or more input devices which may include a panoramic camera system as provided herein and a device that provided positional information of an object, one or more storage devices and display. For instance, the computer game may be a simulation of a tennis game, wherein the person has a game controller or wand in his/her hand to simulate a tennis racket. The WII® game controller of Nintendo® may be such a game controller. The game display may insert the image of the actual user as created by the panoramic system and tracked, and segmented by an image processor into the game display. Such an insert of real-life motion may greatly enhance the game experience for a gamer. The computer game may create a virtual game environment. It may also change and/or enhance the appearance of the inserted image. The image may be inserted from a front view. It may also be inserted from a rear view by the camera. A gamer may use two or more game controllers, which may be wireless. A game controller may be hand held. It may also be positioned on the body or on the head or on any part of the body that is important in a game. A game controller may have a haptic or force-feedback generator that simulates interactive contact with the gaming environment.
In general, gamers use a gaming system and play in a fairly restricted area, such as a bedroom that is relatively small. In such an environment, it is difficult to create a full body image with a single lens camera as the field of vision is generally too small. One may apply a wide angle lens or a fish-eye lens. These lenses may be expensive and/or create distortion in an image. A camera enabled to generate vertical panoramic images such as shown in FIG. 19 enables full body image games as provided above from a small distance. The camera as shown in diagram 1900 has at least two sensor/lens units 1901 and 1902 and at least one autofocus unit 1903. It is not strictly required to use one camera in one body with at least two lenses. One may also position at least two cameras with overlap in one construction and have an external computing device create the vertical panoramic image.
A person may have a length of about 1.50 meter or greater. In general, that means that the position of a camera with one lens has to be at least 300 cm away from the person, if the lens has a field-of-view of sixty degrees. The field of view of a standard 35 mm camera is less than 60 degrees and in most cases will not capture a full size image of a person at a distance of 3 meter, though it may have no trouble focusing on objects at close distances. It may, therefore, be beneficial to apply a panoramic camera as disclosed herein with either two or three lenses, but with at least two lenses to capture a person of 1.50 meter tall or taller at a distant of at least 1.50 meter. Other measurements may also be possible. For instance, a person may be 1.80 meter tall and needs to be captured on a full person image. This may require a camera or a camera system of at least 2 lenses and images sensors, though it may also require a camera or a camera system of 3 lenses and image sensors.
One may want to follow the horizontal movements of a gamer in a restricted area. In such a case the cameras as shown in FIG. 5 and FIG. 18 may be helpful.
A controller or a processor as mentioned herein is a computer device that can execute instructions that are stored and retrieved from a memory. The instructions of a processor or controller may act upon external data. The results of executing instructions are data signals. In the controller these data signals may control a device such as a motor or it may control a processor. An image processor processes image data to create a new image. Both a controller and a processor may have fixed instructions. They may also be programmable. For instance, instructions may be provided by a memory, which may be a ROM, a RAM or any other medium that can provide instructions to a processor or a controller. Processors and controllers may be integrated circuits, they may be programmed general processor, they may be processors with a specific instruction set and architecture. A processor and/or a controller may be realized from discrete components, from programmable components such as FPGA or they may be a customized integrated circuit.
Lens and sensor modules are well known and can be purchased commercially. They may contain single lenses. They may also contain multiple lenses. They may also contain zoom lenses. The units may have integrated focus mechanisms, which may be piezomotors or any other type of motor, mechanism or MEMS (micro-electro-mechanical system). Integrated zoom mechanisms for sensor/lens units are known. Liquid lenses or other variable are also known and may be used. When the term motor is used herein or piezo-motor it may be replaced by the term mechanism, as many mechanisms to drive a position of a lens or a sensor/lens unit are known. Preferably, mechanisms that can be driven or controlled by a signal are used.
FIG. 20 shows a diagram of one embodiment of a sensor/lens unit 2000 in accordance with an aspect of the present invention. The unit has a body 2001 with a sensor 2002, a lens barrel 2003 which contains at least one lens 2004, the barrel can be moved by a mechanism 2005. The lens unit may also contain a zoom mechanism, which is not shown. The unit can be moved relative to the body of the camera by a moving mechanism 2006. The movements that may be included are lateral movement in the plane of the sensor, rotation in the plane of the sensor and rotation of the plane of the sensor, which provides the unit with all required degrees of freedom, as is shown as 208.
Other embodiments are possible. For instance, one may have the lens movable relative to the sensor as is shown in FIG. 21, wherein lens barrel 2103 may be moved in any plane relative to the sensor by lateral mechanisms 2109 and 2112 and by vertical mechanisms 2110 and 2111.
A mechanism may be driven by a controller. This means that the controller has at least an interface with the driving mechanisms in order to provide the correct driving signal. A controller may also have an interface to accept signals such as sensor signals, for instance from an autofocus unit. The core of a controller may be a processor that is able to retrieve data and instructions from a memory and execute instructions to process data and to generate data or instructions to a second device. Such a second device may be another processor, a memory or a MEMS such as a focus mechanism. It was shown herein as an aspect of the present invention that a controller may determine a focus and/or a zoom setting of a camera and depending on this setting provide data to an image processor. The image processor is a processor that is enabled to process data related to an image. In general, instructions and processing of these instructions are arranged in an image processor in such a way that the complete processing of an image happens very fast, preferably in real-time. As processors are becoming much faster and increasingly having multiple cores, real-time processing of images as well as executing control instructions and retrieving and storing of data from and in a single or even multiple memories may be performed in a single chip, which may be called a single processor. Such a single processor may thus perform the tasks of a controller as well as an image processor. The terms controller and image processor may be interpreted as a distinction between functions that can be performed by the same processor. It is also to be understood that flows of instructions and data may be illustrative in nature. For instance, a controller may provide an image processor with the coordinates of a sensor area, which is rotated with respect to the axis system of the sensor. One may actually buffer data from a sensor area, defined by the coordinates, in a memory that represents a rectangular axis system. Different configurations of providing an image processor with the correct data are thus possible that lead to the image processor accessing the exact or nearly exact sensor are a data to exactly or nearly exactly stitch 2 or more images.
For reasons of simplicity, the parameters for camera settings have been so far limited to focus, zoom and position and related active sensor areas. Light conditions and shutter speed, as well as shutter aperture settings, may also be used. In fact, all parameters that play a role in creating a panoramic image may be stored in a memory and associated with a specific setting to be processed or controlled by a controller. Such parameters may for instance include transformational parameters that determine modifying pixels in one or more images to create a panoramic image. For instance, two images may form a panoramic image, but require pixel blending to adjust for mismatching exposure conditions. Two images may also be matched perfectly for a panoramic image, but are mismatched due to lens deformation. Such deformation may be adjusted by a spatial transformation of pixels in one or two images. A spatial transformation may be pre-determined in a calibration step, including which pixels have to be transformed in what way. This may be expressed as parameters referring to one or more pre-programmed transformations, which may also be stored in memory and associated with a reference setting.
The calibration methods provided herein allow an image processor to exactly or nearly exactly match on the pixel two or more images for stitching into a panoramic image. This allows skipping almost completely a search algorithm for registering images. Even if not a complete match is obtained immediately, a registering algorithm can be applied that only has to search a very small search area to find the best match of two images. The image processor may adjust pixel intensities after a match was determined or apply other known algorithms to hide a possible transition line between two stitches images. For instance, it may be determined during calibration that at a lens setting no perfect match between two images can be found due to distortion. One may determine the amount of distortion at the lens setting and have the image processor perform an image transformation that creates two registered images. The same approach applies if the uncertainty between two images is several pixel distances, for instance, due to deviations in driving mechanisms. One may instruct the image processor to for instance perform an interpolation. The parameters of the interpolation may be determined from predetermined pixel positions.
The adjustment of two or more images to create a single registered panoramic along for instance a merge line, may require a transformation of at least one image. It may also require blending of pixel intensities in a transition area. The processing steps for such transformation and or blending may be represented by a code and/or transformation and/or blending parameters. A code and/or parameters may be associated in a calibration step with a setting and conditions related to a reference lens and/or reference sensor unit and saved in a calibration memory which can be accessed by a controller. Thus, the controller will recognize a specific setting of a reference lens and retrieve the associated settings for the other lenses and sensors, including transformation and/or blending parameters and the sensor area upon which all operations have to be performed, including merging of sensor areas.
A controller may be a microcontroller such as a programmable microcontroller. These controllers that take input from external sources such as a sensor and drive a mechanism based on such input and/or previous states are known. Controllers that control aspects of a camera, such as focus, zoom, aperture and the like are also known. Such a controller is for instance disclosed in U.S. Pat. No. 7,259,792 issued on Aug. 21, 2007, and U.S. Pat. No. 6,727,941 issued on Apr. 27, 2004, which are both incorporated herein by reference in their entirety. Such a controller may also be known or be associated with a driving device. Such a driving device is for instance disclosed in U.S. Pat. No. 7,085,484 issued on Aug. 1, 2006, U.S. Pat. No. 5,680,649 issued on Oct. 21, 1997 and U.S. Pat. No. 7,365,789 issued on Apr. 29, 2008, which are all 3 incorporated herein by reference in their entirety.
In one embodiment of the present invention, all images are recorded at substantially the same time. In a second embodiment, at least two images may be taken at substantially not the same time.
In a further embodiment, a camera has 3 or more lenses, each lens being associated with an image sensor. Each lens may be a zoom lens. All lenses may be in a relatively fixed position in a camera body. In such a construction, a lens may focus, and it may zoom, however, it has in all other ways a fixed position in relation to a reference position of the camera. As an illustrative example, lenses are provided in a camera that may be aligned in one line. Such an arrangement is not a required limitation. Lenses may be arranged in any arrangement. For instance 3 lenses may be arranged in a triangle. Multiple lenses may also be arranged in a rectangle, a square, or an array, or a circle, or any arrangement that may provide a stitched image as desired. The calibration of lenses and sensor area may be performed in a similar way as described earlier. Each lens may have its own image sensor. One may also have two or more lenses share a sensor. By calibrating and storing data related to active image sensor areas related to a setting of at least one reference lens, which may include one or more merge lines between image areas of image sensors one may automatically stitch images into one stitched image.
The herein disclosed multi-lens cameras and stitching methods allow creating panoramic or stitched image cameras without expensive synchronization mechanisms to position lenses. The problem of lens coordination which may require expensive mechanisms and control has been changed to a coordination of electronic data generated by image sensors. The coordination of electronic image data has been greatly simplified by a simple calibration step which can be stored in a memory. The calibration data can be used by a controller, which can control focus, zoom and other settings. The memory also has the information on how to merge image data to create a stitched image.
In a further embodiment, one may provide one or more lenses with mechanisms that allow a lens and if required a corresponding image sensor to me moved in such a way that an optimal field of vision, or quality of image or any other criterion for a stitched image that can be achieved by moving lenses can be met.
In yet a further embodiment, one may have a set of lenses each related to an image sensor, a lens having a zoom capability. It is known that a higher zoom factor provides a narrower field of vision. Accordingly, two lenses that in unzoomed position provide a stitched panoramic image, may provide in zoomed position two non-overlapping images that thus cannot be used to form a stitched or panoramic image. In such an embodiment, one may have at least one extra lens positioned between a first and a second lens, wherein the extra lens will not contribute to an image in unzoomed position. However, such an extra lens and its corresponding image sensor, may contribute to a stitched image if a certain zoom factor would create a situation whereby the first and second lens can not create a desired stitched or panoramic image. As was explained before, the relevant merge lines or active areas of an image sensor will be calibrated against for instance a set zoom factor. When a certain zoom factor is reached, an image may be formed from images generated from the first, the second and the extra lens. All those settings can be calibrated and stored in a memory. One may include more extra lenses to address additional and stronger zoom factors.
Aspects of the present invention are applied to the creation of panoramic images using two or more sensor/lens units. There is also a need to create stereographic images using two sensor/lens systems. The aspects of the present invention as applied to two lenses for panoramic images may also be applied to create stereographic images.
A further illustration of processing data of a limited area of an image sensor is provided in FIG. 22. Assume that an image has to be stitched from images generated by a sensor 2201 and a sensor 2202. For illustrative purposes, these sensors are pixel row aligned and are translated with respect to each other over a horizontal line. It should be clear that the sensors may also have a translation in vertical direction and may be rotated with respect to each other. For simplicity, reasons only one translation will be considered. Each sensor is determined by rows of sensor pixels which are represented in diagram by a little square. Each pixel in a sensor is assigned an address or location such as P(1,1) in 2201 in the upper left corner. A pixel P(x,y) represents how a pixel is represented as data for processing. What is called a sensor pixel may be sets of micro sensors able to detect for instance Red, Green or Blue light. Accordingly, what is called a sensor pixel is data that represents a pixel in an image that originates from a sensor area which may be assigned an address on a sensor or in a memory. A pixel may be represented by for instance an RGBA value.
A sensor may generate a W by H pixel image, for instance a 1600 by 1200 pixel image, of 1200 lines, each line having 1600 pixels. In FIG. 22 in 2201 the start of the lowest line at the lower left corner is then pixel P(1200,1). Assume that, during calibration, a stitched image can be formed from pixels along pixel line P(1, n-1) and P(m,n-1), whereby the merge line cuts off the data formed by area defined by P(1,n), P(1,e), P(m,n) and P(m,e) when the merge line is a straight line parallel to the edge of the sensor. However, other merge lines are possible. A second and similar sensor 2202 is used to provide the pixels of the image that has to be merged with the first image to form the stitched image. The sensor 2202 has pixel Q(x,y), which starting pixel at Q(1,1) and bottom pixel line starting at Q(m,1) and the merge line running between Q(1,r-1) and Q(1,r) and Q(m,r-1) and Q(m,r).
One may process the data generated by the image sensors in different ways. One may store only the ‘useful data’ in a contiguous way in a memory. This means that the non-used data such as generated by area P(1,n), P(1,e), P(m,n) and P(m,e) and Q(1,1) Q(1,r-1), Q(m,r-1) and Q(m,1) is not stored. In a first embodiment, one may process the pixels to be stored for blending and transformation before storage. Accordingly, a stitched panoramic image will be stored in memory.
In a second embodiment, one may store data generated by the whole sensor area in a memory. However, one may instruct a memory reader to read only the required data from the memory for display. During reading one may process the data for blending and transformation and display only the read data which may have been processed, which will form a stitched image.
While there have been shown, described and pointed out, fundamental novel features of the invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the methods, systems and devices illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the claims or their equivalents appended hereto.
The following patent application, including the specification, claims and drawings, is hereby incorporated by reference herein, as if it were fully set forth herein: U.S. Non-Provisional patent application Ser. No. 12/435,624 filed on May 5, 2009.

## Claims

1. A method for generating by a portable camera containing a first lens associated with a first image sensor and a second lens associated with a second image sensor a registered panoramic image, comprising:
generating during a calibration a plurality of setting data associated with a first focus position of the first lens by using a focus mechanism, the plurality of setting data defining coordinates of a first active sensor area of the first image sensor which is smaller than the total active area of the first image sensor;
associating the plurality of setting data with a first focus position of the second lens, the plurality of setting data also defining coordinates of a first active sensor area of the second image sensor which is smaller than the total active area of the second image sensor;
storing the plurality of setting data in a memory;
putting the first lens in the first focus position;
the focus mechanism placing the second lens in the first focus position based on the plurality of setting data associated with the first focus position of the first lens;
retrieving by a controller based on data generated by the focus mechanism from the memory the plurality of setting data defining coordinates of the first active area of the first image sensor and coordinates of the first active area of the second image sensor; and
combining image data generated by the first active area of the first image sensor and by the first active area of the second image sensor to generate the registered panoramic image.

2. The method as claimed in claim 1, further comprising:
generating, during the calibration a second plurality of setting data associated with a second focus position of the first lens by using the focus mechanism, the second plurality of setting data defining coordinates of a second active sensor area of the first image sensor, which is smaller than the total active area of the first image sensor;
associating the second plurality of setting data with a second focus position of the second lens, the second plurality of setting data also defining coordinates of a second active sensor area of the second image sensor which is smaller than the total active area of the second image sensor;
storing the second plurality of setting data in the memory;
putting the first lens in the second position;
the focus mechanism placing the second lens in the second focus position based on the second plurality of setting data associated with the second focus position of the first lens;
retrieving by the controller based on data generated by the focus mechanism from the memory the second plurality of setting data defining coordinates of the second active area of the first image sensor and coordinates of the second active area of the second image sensor; and
combining image data generated by the second active area of the first image sensor and by the second active area of the second image sensor to generate a second registered panoramic image.

3. The method as claimed in claim 1, further comprising displaying the registered panoramic image on a display being part of the portable camera.

4. The method as claimed in claim 1, wherein the registered panoramic image is a video image.

5. The method as claimed in claim 1, further comprising the plurality of setting data also being associated with a first zoom setting of the first lens and with a first zoom setting of the second lens.

6. The method as claimed in claim 1, further comprising at least a third lens being associated with a third image sensor.

7. The method as claimed in claim 1, wherein the portable camera is part of a mobile phone.

8. The method as claimed in claim 1, wherein the portable camera is part of a computer gaming system.

9. The method as claimed in claim 1, wherein image data from the image sensors is obtained in accordance with the plurality of setting data.

10. A camera, comprising:
a first and a second imaging unit, each imaging unit including a lens and an image sensor; and
a processor for generating a plurality of setting data during a calibration that determine coordinates of a first active sensor area of the image sensor of the first imaging unit smaller than the total active area of the image sensor of the first imaging unit and coordinates of a first active area of the image sensor of the second imaging unit smaller than the total active area of the image sensor of the second imaging unit to generate a registered panoramic image, wherein the processor obtains and combines image data from the image sensors by applying the plurality of setting data.

11. The camera, as claimed in claim 10, further comprising
a focus mechanism generating data representing a first focus position which causes a first mechanism to put the lens of the first imaging unit in a first position and a second mechanism to put the lens of the second imaging unit in a first position; and
the processor using data representing the first focus position to process image data from the first active areas of the image sensors of the first and the second imaging unit to generate the registered panoramic image.

12. The camera as claimed in claim 10, further comprising at least a third imaging unit including a lens and an image sensor.

13. The camera as claimed in claim 10, wherein the camera is part of a mobile phone.

14. The camera as claimed in claim 10, wherein the image is a video image.

15. The camera as claimed in claim 10, further comprising a first zoom mechanism associated with the lens of the first imaging unit and a second zoom mechanism associated with the lens of the second imaging unit.

16. The camera as claimed in claim 10, wherein the camera is part of a computer gaming system.

17. A controller in a camera for generating a registered panoramic image from a scene with the camera including at least a first and a second lens, a first and a second image sensor, and a focus mechanism associated with the first lens, enabled to generate data representing a focus position, comprising:
a memory, enabled to store and provide setting data associated with a focus position of the first lens;
the controller enabled to retrieve data from the memory and enabled to executing instructions for performing the steps of:
receiving data from the focus mechanism determining a first focus position;
retrieving by using data associated with the first focus position from the memory setting data determining coordinates of a first active area of the first image sensor smaller than a total active area of the first image sensor and coordinates of a first active area of the second image sensor smaller than a total active area of the second image sensor; and
obtaining in accordance with the setting data image data from the first active area of the first image sensor and the first active area of the second image sensor image data to create the registered panoramic image.

18. The controller as claimed in claim 17, wherein determining the active area of the first image sensor depends on a zoom setting of the first lens.

19. The controller as claimed in claim 17, wherein the camera is included with a mobile phone.

20. The controller as claimed in claim 17, wherein the camera is part of a gaming system that segments an object in the registered panoramic image from a background.