Patent Publication Number: US-2005134719-A1

Title: Display device with automatic area of importance display

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
      Reference is made to commonly assigned, co-pending U.S. patent application Ser. No. 10/061,385, filed Feb. 1, 2002, entitled SYSTEM AND METHOD OF PROCESSING A DIGITAL IMAGE FOR USER ASSESSMENT OF AN OUTPUT IMAGE PRODUCT, in the name of Fredlund et al.; U.S. Ser. No. 10/324,489, filed Dec. 20, 2002, entitled IMAGING METHOD AND SYSTEM FOR DETERMINING AN AREA OF IMPORTANCE IN AN ARCHIVAL IMAGE, in the name of John R. Fredlund; and U.S. Patent Application Publication No. 2003/0117511A1, filed Dec. 21, 2001, entitled METHOD AND CAMERA SYSTEM FOR BLURRING PORTIONS OF A VERIFICATION IMAGE TO SHOW OUT OF FOCUS AREAS IN A CAPTURED ARCHIVAL IMAGE, in the name of Belz et al., all of which are incorporated herein. 
    
    
     FIELD OF THE INVENTION  
      The present invention relates to electronic imaging systems having a display for presenting images.  
     BACKGROUND OF THE INVENTION  
      Hand held and portable display devices are becoming increasingly popular communication tools for capturing, sharing and displaying images that are in digital form. Examples of such devices include digital cameras, hybrid/film electronic cameras, personal digital assistants, digital photo albums, so called e-books, CD and DVD players and the like. Because many consumers prefer display devices that are relatively small, many display devices provide video displays that are also relatively small and therefore such displays have limited image resolution capacity. For example, the image resolving capability of the displays in some of the most popular hand held devices is on the order of 320 picture elements (referred to herein as “pixels”) by 320 pixels. However, it is not uncommon for digital images to be on the order of 2000 pixels by 2000 pixels. Thus, in this respect, portable displays typically have a limited image resolution as compared to the images that they are used to present.  
      The relatively limited image resolution of such displays requires that image content in a digital image must typically be down sampled to form the evaluation image for presentation on the display. However, the limited image resolution can make it difficult to detect image conditions that can lead to dissatisfaction with a digital image. For example, this down sampling causes an increase in the apparent sharpness of evaluation image that can mask a lack in sharpness in the archival image. Thus, a lack of sharpness in the archival image that is caused, for example, by focusing error during capture of the archival image may not be readily apparent in the evaluation image presented on the display.  
      Other image elements that may lead to user dissatisfaction with the captured archival image can also be masked in the evaluation image by the down sampling process. For example, the down sampling process can form evaluation images that mask conditions such as red eye, closed eyes, subject motion, handshake and/or other lighting conditions that will be readily apparent when the archival image is presented by display having better resolution or when the archival image is printed. Thus, what is needed is a display device such as a camera with a camera with a display that more effectively presents an image in a way that automatically assists a user in the process of reviewing a digital image.  
      Various approaches have been used to help a user to determine whether conditions exist in a stored digital image that can lead to dissatisfaction with the stored digital image and that will be masked by the down sampling. For example, commonly-assigned U.S. Pat. No. 5,103,254, entitled “Camera with Subject Highlighting and Motion Detection,” filed by Bell et al. on May 29, 1990 discloses a camera in which a gradient operation is performed on an electronically captured image, in order to produce an outline of subjects within the depth of field. This outline is displayed using a liquid crystal display (LCD) as a mask to highlight the in-focus subject within the camera&#39;s viewfinder. Similarly, U.S. Pat. No. 5,496,106, entitled “System and Method of Generating a Contrast Overlay as a Focus Assist for an Display device,” filed by Anderson on Dec. 13, 1994, discloses a system in which an image is split into its red, green, and blue components, a contrast signal is generated, and the contrast signal is combined with one of the color channels to produce a false-color overlay that indicates which area of the captured image is in focus. These color overlays help the photographer by showing the photographer an evaluation image that with a false color overlay indicating portions of the archival image that have been captured in focus. This in turn allows the photographer to determine whether the intended subject of the image was captured in the archival image in focus.  
      Similarly, commonly assigned U.S. Patent Application Publication No. 2003-0117511A1 entitled “Method and Camera System for Blurring Portions of an Evaluation Image to Show Out of Focus Areas in a Captured Archival Image” filed on Dec. 21, 2001 by Belz et al. describes a camera that detects out of focus areas in an archival image and causes the appearance of the portions of the evaluation image that corresponds to the out of focus areas in the archival image to have a blurred or out of focus appearance when presented on a display.  
      In some digital cameras, such as the DC-215 camera sold by Eastman Kodak Company, Rochester, N.Y., U.S.A. this problem is addressed by presenting evaluation images at one of two manually selected levels of magnification. In a first mode, the entire evaluation image is formatted and presented on a video display so that the entire evaluation image can be viewed in the display. In a second mode, only a part of the evaluation image can be viewed on the display. Because the entire display or a substantial proportion thereof is used for presenting only a portion of the image, the portion of the evaluation image being viewed has a greater effective magnification than it has when that same portion is viewed in the first mode.  
      The user can manually adjust what is displayed so that particular portions of the evaluation image can be viewed with increased magnification. However, this requires that a photographer manually selects the magnification mode and manually locates an area of importance in the image in order to make determinations.  
      It will also be appreciated that as the memory capacity of hand held display devices continues to increase and as the ability of such devices to retrieve images from remote image servers using wired and wireless communication systems becomes more prevalent, such hand-held image display devices are increasingly called upon to present more than one evaluation image at a time. For example a collection of images may be available for viewing using the display device. To help a consumer to sort through these images, it is well known to provide a menu of so-called thumbnail images that each use only a fraction of the image forming capabilities of the display. Where this is done, the extent of the down sampling is increased further masking conditions in an image that may make the image have a less than desirable appearance. Further, in certain circumstances, it can become difficult to discern what is depicted in the thumbnail image.  
      Thus, what is also needed is a method of forming evaluation images that can be used to facilitate evaluation of archival images when presented in thumbnail form.  
     SUMMARY OF THE INVENTION  
      In one embodiment, the invention is a method for forming an evaluation image for presentation on a display. In accordance with the method an image is obtained having a resolution greater than a resolution of the display and an area of importance automatically determined comprising less than all of the obtained image. Image elements from the area of importance are used to form an area of importance image adapted for presentation on the display; and the area of importance image is presented.  
      In another embodiment, the invention is a method for using a display having a predetermined image resolution to display an image have greater image resolution than the display. In accordance with the method the image is obtained and an area of importance is determined in the obtained image. An area of importance image is formed containing image information from the area of importance resampled for presentation at the image resolution of the display and the area of importance image is presented on the display.  
      Another embodiment of the invention is a method for using a display having a predetermined image resolution to display an image have greater image resolution than the display. In accordance with the method the image is obtained and an area of importance is determined in the obtained image. An evaluation image is formed having an appearance that corresponds to the obtained image and is resampled for presentation on the display and the evaluation image is presented. An area of importance image is formed containing imaging information that corresponds to the area of importance resampled for presentation at the display resolution and presenting the area of importance image on the display when an area of importance verification mode is selected.  
      Another embodiment of the invention is a method for presenting an area of importance in an image. In accordance with the method, an archival image is obtained and an evaluation image is formed corresponding to the appearance of the archival image and resampled for presentation on the display. An area of importance is determined in the archival image. The area of importance comprises less than all of the archival image. An evaluation image is displayed that corresponds to the archival image and an area of importance image is displayed that contains image content that corresponds to the determined area of importance. Wherein the image content of the area of importance as displayed in the area of importance image has a greater effective magnification than the area of importance has as displayed in an evaluation image that corresponds to the archival image.  
      Another embodiment of the invention is a display device. In this embodiment, the display device has a source of archival images operable to obtain archival images; a display; and a processor adapted to determine an area of importance in an obtained archival image, and to form an area of importance image that contains less than all of the archival image including image information from the area of importance and that is adapted to be presented on the display and to cause the display to present the area of importance image.  
      Still another embodiment of the invention is a display device. The display device has a source of an archival image; a display; and a signal processor. The signal processor receives the archival image and is capable of forming images for presentation on the display based upon the archival image. A controller is provided and is operable to cause the signal processor to form an evaluation image for presentation on the display and to form an area of importance image for presentation on the display. Wherein the evaluation image depicts what is shown in the archival image and the area of interest image depicts only a portion of the archival image that corresponds to the area of importance. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an illustration of one embodiment of a display device of the present invention;  
       FIG. 2  is an illustration of a back view of the display device of  FIG. 1 ;  
       FIG. 3  is a flow diagram of one embodiment of a method of the present invention;  
       FIG. 4  illustrates a photographic scene separated into rangefinding regions;  
       FIG. 5  illustrates an area of importance displayed as part of an evaluation image;  
       FIG. 6  illustrates a displayed area of importance image;  
       FIG. 7  illustrates another embodiment of a method of the invention;  
       FIG. 8  illustrates another embodiment of a method of the invention;  
       FIGS. 9   a ,  9   b , and  9   c  each show an archival image;  
       FIG. 10  shows a conventional thumbnail listing of archival images;  
       FIG. 11  shows a thumbnail listing of area of importance thumbnail images;  
       FIG. 12  shows one example embodiment of a combined display of an evaluation image and an area of importance image; and  
       FIG. 13  shows another example embodiment of a combined display of an evaluation image and an area of importance image. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
       FIG. 1  shows a block diagram of an embodiment of a display device  10 .  FIG. 2  shows a back, elevation view of the display device  10  of  FIG. 1 . As is shown in  FIGS. 1 and 2 , display device  10  takes the form of a digital camera  12  comprising a body  20  containing an image capture system  22  having a lens system  23 , an image sensor  24 , a signal processor  26 , an optional display driver  28  and a display  30 . In operation, light from a scene is focused by lens system  23  to form an image on image sensor  24 . Lens system  23  can have one or more elements.  
      Lens system  23  can be of a fixed focus type or can be manually or automatically adjustable. In the embodiment shown in  FIG. 1 , lens system  23  is automatically adjusted. Lens system  23  can be simple, such as having a single focal length with manual focusing or a fixed focus. In the example embodiment shown in  FIG. 1 , taking lens unit  22  is a motorized  6 ×zoom lens unit in which a mobile element or elements (not shown) are driven, relative to a stationary element or elements (not shown) by lens driver  25 . Lens driver  25  controls both the lens focal length and the lens focus position of lens system  23  and sets a lens focal length and/or position based upon signals from signal processor  26 , an optional automatic range finder system  27 , and/or controller  32 .  
      The focal length and/or focus position of lens system  23  can be automatically selected using a variety of known strategies. For example, in one embodiment, image sensor  24  is used to provide multi-spot autofocus using what is called the “through focus” or “whole way scanning” approach. In such an approach the scene is divided into a grid of regions or spots, and the optimum focus distance is determined for each image region. The optimum focus distance for each region is determined by moving lens system  23  through a range of focus distance positions, from the near focus distance to the infinity position, while capturing images. Depending on the design of digital camera  12 , between four and thirty-two images may need to be captured at different focus distances. Typically, capturing images at eight different distances provides suitable accuracy.  
      The captured image data is then analyzed to determine the optimum focus distance for each image region. This analysis begins by band-pass filtering the sensor signal using one or more filters, as described in commonly assigned U.S. Pat. No. 5,874,994 “Filter Employing Arithmetic Operations for an Electronic Synchronized Digital Camera” filed by Xie et al., on Dec. 11, 1995, the disclosure of which is herein incorporated by reference. The absolute value of the bandpass filter output for each image region is then peak detected, in order to determine a focus value for that image region, at that focus distance. After the focus values for each image region are determined for each captured focus distance position, the optimum focus distances for each image region can be determined by selecting the captured focus distance that provides the maximum focus value, or by estimating an intermediate distance value, between the two measured captured focus distances which provided the two largest focus values, using various interpolation techniques.  
      The lens focus distance to be used to capture a digital image can be determined using known algorithms. In a preferred embodiment, the image regions corresponding to a target object (e.g. a person being photographed) are determined. The focus position is then set to provide the best focus for these image regions. For example, an image of a scene can be divided into a plurality of sub-divisions. A focus evaluation value representative of the high frequency component contained in each subdivision of the image can be determined and the focus evaluation values can be used to determine object distances as described in commonly assigned U.S. Pat. No. 5,877,809 entitled “Method Of Automatic Object Detection In An Image”, filed by Omata et al. on Oct. 15, 1996, the disclosure of which is herein incorporated by reference. If the target object is moving, object tracking may be performed, as described in commonly assigned U.S. Pat. No. 6,067,114 entitled “Detecting Compositional Change in Image” filed by Omata et al. on Oct. 26, 1996, the disclosure of which is herein incorporated by reference. In an alternative embodiment, the focus values determined by “whole way scanning” are used to set a rough focus position, which is refined using a fine focus mode, as described in commonly assigned U.S. Pat. No. 5,715,483, entitled “Automatic Focusing Apparatus and Method”, filed by Omata et al. on Oct. 11, 1998, the disclosure of which is herein incorporated by reference.  
      In one embodiment, bandpass filtering and other calculations used to provide auto-focus information for digital camera  12  are performed by digital signal processor  26 . In this embodiment, digital camera  12  uses a specially adapted image sensor  24 , as is shown in commonly assigned U.S. Pat. No. 5,668,597 entitled “An Electronic Camera With Rapid Automatic Focus Of An Image Upon A Progressive Scan Image Sensor”, filed by Parulski et al. on Dec. 30, 1994, the disclosure of which is herein incorporated by reference, to automatically set the lens focus position. As described in the &#39;597 patent, only some of the lines of sensor photoelements (e.g. only ¼ of the lines) are used to determine the focus. The other lines are eliminated during the sensor readout process. This reduces the sensor readout time, thus shortening the time required to focus lens system  23 .  
      In an alternative embodiment, digital camera  12  uses a separate optical or other type (e.g. ultrasonic) of rangefinder  27  to identify the subject of the image and to select a focus position for lens system  23  that is appropriate for the distance to the subject. Rangefinder  27  can operate lens driver  25 , directly or as shown in  FIG. 1 , can provide signals to signal processor  26  or controller  32  from which signal processor  26  or controller  32  can generate signals that are to be used for image capture. A wide variety of suitable multiple sensor rangefinders  27  known to those of skill in the art are suitable for use. For example, U.S. Pat. No. 5,440,369 entitled “Compact Camera With Automatic Focal Length Dependent Exposure Adjustments” filed by Tabata et al. on Nov. 30, 1993, the disclosure of which is herein incorporated by reference, discloses one such rangefinder  27 . The focus determination provided by rangefinder  27  can be of the single-spot or multi-spot type. Preferably, the focus determination uses multiple spots. In multi-spot focus determination, the scene is divided into a grid of areas or spots, and the optimum focus distance is determined for each spot. One of the spots is identified as the subject of the image and the focus distance for that spot is used to set the focus of lens system  23 .  
      A feedback loop is established between lens driver  25  and camera controller  32  so that camera controller  32  can accurately set the focus position of lens system  23 .  
      Lens system  23  is also optionally adjustable to provide a variable zoom. In the embodiment shown lens driver  25  automatically adjusts the position of one or more mobile elements (not shown) relative to one or more stationary elements (not shown) of lens system  23  based upon signals from signal processor  26 , an automatic range finder system  27 , and/or controller  32  to provide a zoom magnification. Lens system  23  can be of a fixed magnification, manually adjustable and/or can employ other known arrangements for providing an adjustable zoom.  
      Light from the scene that is focused by lens system  23  onto image sensor  24  is converted into image signals representing an image of the scene. Image sensor  24  can comprise a charge couple device (CCD), a complimentary metal oxide sensor (CMOS), or any other electronic image sensor known to those of ordinary skill in the art. The image signals can be in digital or analog form.  
      Signal processor  26  receives image signals from image sensor  24  and transforms the image signals into an image in the form of digital data. The digital image can comprise one or more still images, multiple still images and/or a stream of apparently moving images such as a video segment. Where the digital image data comprises a stream of apparently moving images, the digital image data can comprise image data stored in an interleaved or interlaced image form, a sequence of still images, and/or other forms known to those of skill in the art of digital video.  
      Signal processor  26  can apply various image processing algorithms to the image signals when forming a digital image. These can include but are not limited to color and exposure balancing, interpolation and compression. Where the image signals are in the form of analog signals, signal processor  26  also converts these analog signals into a digital form.  
      Controller  32  controls the operation the display device  10  during imaging operations, including but not limited to image capture system  22 , display  30  and memory such as memory  40 . Controller  32  causes image sensor  24 , signal processor  26 , display  30  and memory  40  to capture and store archival images in response to signals received from a user input system  34 , data from signal processor  26  and data received from optional sensors  36 . Controller  32  can comprise a microprocessor such as a programmable general purpose microprocessor, a dedicated micro-processor or micro-controller, a combination of discrete components or any other system that can be used to control operation of display device  10 .  
      Controller  32  cooperates with a user input system  34  to allow display device  10  to interact with a user. User input system  34  can comprise any form of transducer or other device capable of receiving an input from a user and converting this input into a form that can be used by controller  32  in operating display device  10 . For example, user input system  34  can comprise a touch screen input, a touch pad input, a 4-way switch, a 6-way switch, an 8-way switch, a stylus system, a trackball system, a joystick system, a voice recognition system, a gesture recognition system or other such systems. In the digital camera  12  embodiment of display device  10  shown in  FIGS. 1 and 2  user input system  34  includes a shutter trigger button  60  that sends a trigger signal to controller  32  indicating a desire to capture an image.  
      In the embodiment shown in  FIGS. 1 and 2 , user input system  34  also includes a wide-angle zoom button  62 , and a tele-zoom button  64  that cooperate with controller  32  to control the zoom settings of lens system  23  causing lens system  23  to zoom out when wide angle zoom button  62  is depressed and to zoom in when tele-zoom button  64  is depressed. Wide-angle zoom lens button  62  and telephoto zoom button  64  can also be used to provide signals that cause signal processor  26  to process image signal so that the digital image formed thereby appears to have been captured at a different zoom setting than that actually provided by the optical lens system. This can be done by using a subset of the image signals from image sensor  24  and interpolating the subset of the image signals to form the digital image. User input system  34  can also include other buttons including joystick  66  shown in  FIG. 2 , the mode selector button  67  and select-it button  68  shown in  FIG. 2 , the function of which will be described in greater detail below.  
      Sensors  36  are optional and can include light sensors and other sensors known in the art that can be used to detect conditions in the environment surrounding display device  10  and to convert this information into a form that can be used by controller  32  in governing operation of display device  10 . Sensors  36  can also include biometric sensors adapted to detect characteristics of a user for security and affective imaging purposes.  
      Controller  32  causes an image signal and corresponding digital image to be formed when a trigger condition is detected. Typically, the trigger condition occurs when a user depresses shutter trigger button  60 , however, controller  32  can determine that a trigger condition exists at a particular time, or at a particular time after shutter trigger button  60  is depressed. Alternatively, controller  32  can determine that a trigger condition exists when optional sensors  36  detect certain environmental conditions.  
      Controller  32  can also be used to generate metadata in association with each image. Metadata is data that is related to a digital image or a portion of a digital image but that is not necessarily observable in the image data itself. In this regard, controller  32  can receive signals from signal processor  26 , camera user input system  34  and other sensors  36  and, optionally, generates metadata based upon such signals. The metadata can include but is not limited to information such as the time, date and location that the archival image was captured, the type of image sensor  24 , mode setting information, integration time information, taking lens unit setting information that characterizes the process used to capture the archival image and processes, methods and algorithms used by display device  10  to form the archival image. The metadata can also include but is not limited to any other information determined by controller  32  or stored in any memory in display device  10  such as information that identifies display device  10 , and/or instructions for rendering or otherwise processing the digital image with which the metadata is associated. The metadata can also comprise an instruction to incorporate a particular message into digital image when presented. Such a message can be a text message to be rendered when the digital image is presented or rendered. The metadata can also include audio signals. The metadata can further include digital image data. The metadata can also include any other information entered into display device  10 .  
      The digital images and optional metadata, can be stored in a compressed form. For example where the digital image comprises a sequence of still images, the still images can be stored in a compressed form such as by using the JPEG (Joint Photographic Experts Group) ISO 10918-1 (ITU-T.81) standard. This JPEG compressed image data is stored using the so-called “Exif” image format defined in the Exchangeable Image File Format version 2.2 published by the Japan Electronics and Information Technology Industries Association JEITA CP-3451. Similarly, other compression systems such as the MPEG-4 (Motion Pictures Export Group) or Apple QuickTime™ standard can be used to store digital image data in a video form. Other image compression and storage forms can be used.  
      The digital images and metadata can be stored in a memory such as memory  40 . Memory  40  can include conventional memory devices including solid state, magnetic, optical or other data storage devices. Memory  40  can be fixed within display device  10  or it can be removable. In the embodiment of  FIG. 1 , display device  10  is shown having a memory card slot  46  that holds a removable memory  48  such as a removable memory card and has a removable memory interface  50  for communicating with removable memory  48 . The digital images and metadata can also be stored in a remote memory system  52  that is external to display device  10  such as a personal computer, computer network or other imaging system.  
      In the embodiment shown in  FIGS. 1 and 2 , display device  10  has a communication module  54  for communicating with the remote memory system. The communication module  54  can be for example, an optical, radio frequency or other transducer that converts image and other data into a form that can be conveyed to the remote display device by way of an optical signal, radio frequency signal or other form of signal. Communication module  54  can also be used to receive a digital image and other information from a host computer or network (not shown). Controller  32  can also receive information and instructions from signals received by communication module  54  including but not limited to, signals from a remote control device (not shown) such as a remote trigger button (not shown) and can operate display device  10  in accordance with such signals.  
      Signal processor  26  and/or controller  32  also use image signals or the digital images to form evaluation images which have an appearance that corresponds to archival images stored in display device  10  and are adapted for presentation on display  30 . This allows users of display device  10  to use a display such as display  30  to view images that correspond to archival images that are available in display device  10 . Such images can include, for example images that have been captured by image capture system  22 , and/or that were otherwise obtained such as by way of communication module  54  and stored in a memory such as memory  40  or removable memory  48 .  
      Display  30  can comprise, for example, a color liquid crystal display (LCD), organic light emitting display (OLED) also known as an organic electro-luminescent display (OELD) or other type of video display. Display  30  can be external as is shown in  FIG. 2 , or it can be internal for example used in a viewfinder system  38 . Alternatively, display device  10  can have more than one display  30  with, for example, one being external and one internal.  
      Signal processor  26  and/or controller  32  can also cooperate to generate other images such as text, graphics, icons and other information for presentation on display  30  that can allow interactive communication between controller  32  and a user of display device  10 , with display  30  providing information to the user of display device  10  and the user of display device  10  using user input system  34  to interactively provide information to display device  10 . Display device  10  can also have other displays such as a segmented LCD or LED display (not shown) which can also permit signal processor  26  and/or controller  32  to provide information to user  10 . This capability is used for a variety of purposes such as establishing modes of operation, entering control settings, user preferences, and providing warnings and instructions to a user of display device  10 . Other systems such as known systems and actuators for generating audio signals, vibrations, haptic feedback and other forms of signals can also be incorporated into display device  10  for use in providing information, feedback and warnings to the user of display device  10 .  
      Typically, display  30  has less imaging resolution than image sensor  24 . Accordingly, signal processor  26  reduces the resolution of image signal or digital image when forming evaluation images adapted for presentation on display  30 . Down sampling and other conventional techniques for reducing the overall imaging resolution can be used. For example, resampling techniques such as are described in commonly assigned U.S. Pat. No. 5,164,831 “Electronic Still Camera Providing Multi-Format Storage Of Full And Reduced Resolution Images” filed by Kuchta et al., on Mar. 15, 1990, can be used. The evaluation images can optionally be stored in a memory such as memory  40 . The evaluation images can be adapted to be provided to an optional display driver  28  that can be used to drive display  30 . Alternatively, the evaluation images can be converted into signals that can be transmitted by signal processor  26  in a form that directly causes display  30  to present the evaluation images. Where this is done, display driver  28  can be omitted.  
      Display device  10  can obtain archival images for processing in a variety of ways. For example, display device  10  can obtain digital images using image capture system  22  as described above. Imaging operations that can be used to obtain digital images using image capture system  22  include a capture process and can optionally also include a composition process and a verification process.  
      During the optional composition process, controller  32  optionally provides an electronic viewfinder effect on display  30 . In this regard, controller  32  causes signal processor  26  to cooperate with image sensor  24  to capture preview digital images during composition and to present a corresponding evaluation images on display  30 .  
      In the embodiment shown in  FIGS. 1 and 2 , controller  32  enters the image composition process when shutter trigger button  60  is moved to a half depression position. However, other methods for determining when to enter a composition process can be used. Any component of user input system  34  can be used for this purpose; for example, the “mode” button  67  or the “select-it” button  68  shown in  FIG. 2  can be depressed by a user of display device  10 , and can be interpreted by controller  32  as an instruction to enter the composition process. The evaluation images presented during composition can help a user to compose the scene for the capture of an archival image.  
      The capture process is executed in response to controller  32  determining that a trigger condition exists. In the embodiment of  FIGS. 1 and 2 , a trigger signal is generated when shutter trigger button  60  is moved to a full depression condition and controller  32  determines that a trigger condition exists when controller  32  detects the trigger signal. During the capture process, controller  32  sends a capture signal causing signal processor  26  to obtain image signals from image sensor  24  and to process the image signals to form digital image data comprising an archival image.  
      During the verification process, an evaluation image corresponding to the digital image is optionally formed for presentation on display  30  by signal processor  26  based upon the image signal. In one alternative embodiment, signal processor  26  converts each image signal into an archival image and then derives the corresponding evaluation image from the archival images. The corresponding evaluation image is supplied to display  30  and is presented for a period of time. This permits a user to verify that the archival image has a preferred appearance.  
      Digital images can also be obtained by display device  10  in ways other than image capture. For example digital images can by conveyed to display device  10  when such images are recorded on a removable memory  48  that is operatively associated with memory interface  50 . Alternatively, digital images can be received by way of communication module  54 . Where communication module  54  is adapted to communicate by way of a cellular telephone network, communication module  54  can be associated with a cellular telephone number or other identifying number that for example another user of the cellular telephone network such as the user of a telephone equipped with a digital camera can use to establish a communication link between display device  10  and a remote memory  52  such as an image sensor (not shown) which can transmit images that are received by communication module  54 . Accordingly, there are a variety of ways in which display device  10  can receive images and therefore it is not essential that display device  10  have an image capture system so long as other means such as those described above are available for importing images into display device  10 .  
       FIG. 3  shows one embodiment of a method for presenting an area of importance image. As is shown in  FIG. 3 , an archival digital image is obtained and stored. This can be done by capture, or by importing the archival images as discussed above or using other conventional archival image capture or downloading techniques (step  100 ).  
      An area of importance determination is then made that identifies an area within the archival image that contains image content that is determined to be important (step  102 ).  
      Image content that corresponds to image content from the area importance in the archival image is then used to form an area of importance image (step  104 ). This image content can be down sampled and/or otherwise processed in a manner that allows the area of importance image to be presented on display  30  (step  106 ). Because less than all of the stored image is presented on display  30 , the extent of the down sampling used form the area of importance image is lower than the extent of the down sampling that would be required to present an evaluation image that includes all of the image content from the archival image on display  30 . Therefore, the area of importance image shows image content from the area of importance as having an appearance that is apparently magnified as compared to appearance of the same image content in the evaluation image.  
      To avoid confusion, a warning such as video, audio, or other signals can optionally be presented along with the area of importance evaluation image to indicate to user of display device  10  that the image being presented does not include all of the captured in stored image content of the archival image (step  108 ).  
      Determining the Area of Importance  
      There are a variety of ways in which the area of importance can be automatically determined for use in generating an area of importance image. In one embodiment, the area of importance determination is based upon auto-focusing information. For example, in the embodiment of  FIGS. 1 and 2 , signal processor  26  and/or camera controller  32  can use information obtained during an automatic focusing process to determine which area of an image is an area of importance. As is discussed above, multi-spot range finding techniques used for focus setting determine focus distances for a number of areas or spots within a photographic scene. These techniques further identify a subject area or spot containing the subject of the scene. A focus distance for that area is used to the set the focus distance of lens system  23  during the process of capturing and storing the image. Where this is done, signal processor  26 , and controller  32  define the area of importance within the stored image as an area that corresponds to the subject area. As will be discussed in greater detail below, a variety of other methods can be used to determine the area of importance.  
       FIG. 4  illustrates in detail, how autofocus information can be used to determine an area of importance. As is shown in  FIG. 4 , during a range finding operation a photographic scene  110  is divided into a series of focus regions,  112 ,  114  and  116 . Region  116  is selected as the subject of the image using conventional auto-focusing regions and/or manual input. Lens system  23  is then adjusted based upon the distance from rangefinder  27  to region  116 .  
      As is shown in  FIG. 5 , an archival image of scene  110  is captured and an evaluation image  118  is formed for presentation on display  30 . An area of importance  120  corresponding to region  116  is identified. As can be observed in the shape, size, and other characteristics of area of importance  120  can be defined in any of a number of ways. For example, area of importance  120  can comprise a predefined or user defined area of importance template  121  that is located within the archival image based upon the identified region. In another example, the area of importance  120  can be adaptively defined based upon characteristics of the scene  110  or by analysis of only the portion of the scene in the subject area  116  such as an illumination pattern, focus pattern and other such image characteristics.  
      As is illustrated in  FIG. 5 , area of importance  120  comprises only a fraction of the total evaluation image  118  and therefore when evaluation image  118  is presented using display  30 , area of importance  120  comprises a corresponding fraction of the total evaluation image  118  and therefore has an initial magnification level that is relatively small.  
       FIG. 6  shows an area of importance image  122  formed by obtaining image information from an area of the archival image that corresponds to the area of importance  120 . In this illustration, the obtained image information is contained within the area of importance template  121 . The image information obtained from within area of importance template  121  is resampled form the area of importance image  122  for presentation on a larger fraction of the display  30  than is occupied by the area of importance  120  when the entire evaluation image  118  is presented on display  30 . This increases the effective magnification of area of importance  120 . This also provides a user of display device  10  with a better opportunity to detect problems in area of importance  120 . Area of importance image  122  can comprise only obtained image information from the area of importance and can also comprise other image information from image  118 . Here too, a predefined template (not shown) can be used to determine what image information is contained within the area of importance image  122  or the image information contained within the area of importance image can be adaptively defined based upon analysis of the scene, the archival image, or the area of importance.  
      Alternatively, it will be recalled that in other embodiments, through focusing or whole way scanning techniques can be used to determine a focus distance for taking lens system  23 . As is discussed in above, during the process of “through focusing” or “whole way scanning”, an area of the scene is identified as the subject of the image and taking lens system  23  is set to a focus distance that is appropriate for capturing this area of the scene in focus. The area of the scene selected for focus can be correlated to the captured archival image to identify the area of importance in the archival image in a manner similar to that described with reference to  FIGS. 4, 5 , and  6 .  
       FIG. 7  shows another method for determining an area of importance in an archival image. In this embodiment, methods described in commonly assigned U.S. patent application Ser. No. 10/324,489 entitled IMAGING METHOD AND SYSTEM FOR DETERMINING AN AREA OF THE IMPORTANCE IN AN ARCHIVAL IMAGE filed by Fredlund on Dec. 20, 2002, are used to determine an area of importance based upon changes made in the field of view of the image capture system during image composition.  
      In the embodiment of  FIG. 7 , display device  10  comprises for example, a digital camera  12  that includes an image capture system  22 . Digital camera  12  obtains an archival image by using an image composition process as described above. During the image composition process, a set of evaluation images are captured ( 130 ). An archival image is captured and stored (step  132 ). An evaluation image corresponding to the archival image is formed (step  134 ). The corresponding evaluation image is compared to the set of evaluation images to identify common portions of the evaluation images (step  136 ). Area of importance data is generated indicating the portions of the stored archival image that correspond to the common portions of the evaluation images (step  138 ). The area of importance data is then associated with the archival image (step  140 ). The area of importance data associated with the archival image is then used to identify portions of the archival image that are in the area of importance (step  142 ).  
      In this way, the area of importance information can be determined during capture without use of auto-focusing algorithms. Other techniques for determining an area of importance in a digital image using one or more evaluation images captured during image composition can also be used such as other methods described in the above identified Fredlund application.  
      In another alternate embodiment image analysis techniques are used to identify an area importance in a stored archival image. For example, large oval shaped objects having color that approximates known flesh tones can be assumed to be important. The degree of presumed importance can be increased where, for example, the large oval face shaped objects are positioned near the center of an image. See for example, commonly assigned U.S. Pat. No. 6,282,317, entitled “Method For Automatic Determination of Main Subjects in Photographic Images”, filed by Luo et al. on Dec. 31, 1998.  
      Image analysis of the archival image can further detect the presence of preferred subjects in the archival image. For example, many consumer cameras for typically owned by a single user or family and therefore, images that contains family members and portions of images that contain family members can be presumed to be of importance. In this regard, display device  10  can receive template images that identify for example family members, or other and objects photographic subjects that can be of interest. In this embodiment, the stored digital images are analyzed to locate the faces, objects, or image patterns of interest within the stored digital images and, portions of the digital image containing the faces, objects, or image patterns of interest can be identified as an area importance. Thus, where analysis of its archival images indicates that certain portions of the archival images contain an image of a family member, an area importance can be defined in an area that surrounds the image of the family member.  
      In another embodiment, frequency analysis of the digital data that forms the stored digital image can be used to identify elements of the stored digital image that are considered to be of greater importance. Such algorithms can be used to make assumptions about what is important in an image based upon analysis of the visual elements of the captured image. See for example commonly assigned U.S. patent application Ser. No. 09/176,805 entitled “Determining Portions of a Digital Image Which are In Focus”, filed by Erkkilea et al. on Oct. 22, 1998 and incorporated herein by reference. In the &#39;805 application, a frequency information in digital data comprising a stored digital image is analyzed to identify at least one area of the stored digital image that is believed to be in focus and a map circumscribing this area is overlaid on the displayed evaluation image. The same techniques described in the &#39;805 application can also be used to identify an area of importance with the area of importance being based upon the area determined to be in focus.  
      In some situations, it can occur that an image stored in display device  10  will be associated with some form of metadata that indicates which portions of the stored digital image comprise an area of importance. For example, stored digital images may contain metadata calling for artificially induced artifacts to be included in the archival image such as borders, text, and other material that at least partially block the image. Areas of the archival image that are blocked by such artifacts can be considered to be outside the area of importance. In another example, the stored digital images can contain metadata with editing instructions such as aspect ratio selections or recommendations that can be used to define portions of the stored digital image that comprise the area of importance. Where such metadata is found in association with the image the metadata can be used to define portions of the stored digital image that comprise the area of importance. A single display device  10  can use one or more than one of the above described methods for determining an area of importance in a stored digital image.  
      In a still further embodiment, signal processor  26  and controller  32  are adapted to analyze illumination patterns in the an archival image and determine, based upon analysis of the illumination patterns, where the area importance is in the archival image. For example, is known to use cameras to provide many as 30,000 potential scene configurations in a memory and comparing illumination patterns from a scene to the potential scene configurations in order to make exposure and focus determinations. The same techniques that are used to make focus determinations can also be used to identify an area of importance.  
      Presentation of Area of Importance Image  
      There are various ways in which the evaluation image can be presented to a user of the display device  10 . In one embodiment, an display device  10  can be adapted to automatically present area of importance images whenever an image is to be evaluated. This mode of operation can be preset. This mode can also be selectably set using for example user input system  34 .  
      In other embodiments, a combination of an evaluation image and an area of importance image can be provided to facilitate the image review process. For example,  FIG. 8  shows a embodiment for displaying the evaluation image and area of importance image during one verification process. In this embodiment, display device  10  obtains an archival image for example by using image capture system  22  to capture the image and store the archival image in a memory (step  150 ). An evaluation image is then formed in the manner described above having an appearance that generally corresponds to the composition and content of the stored archival image but is resampled and/or otherwise adapted for presentation on exterior display  30  (step  152 ).  
      The evaluation image is presented (step  154 ) for a first display period that typically begins immediately after the evaluation image is prepared and extends for a period of time that is that is long enough to permit user to observe and examine the evaluation image (step  156 ).  
      An optional mode detection determining step (step  158 ) is also provided. In this step, controller  32  determines whether to automatically present an area of importance image in addition to the evaluation image. In one embodiment, this determination is made manually, with a user entering a mode selection that way of user input system  34 . This mode selection can comprise selecting that an area of importance presentation image will automatically be presented after each evaluation image. Alternatively, the mode selection can be manually executed by monitoring user interface system  34  during presentation of the evaluation image to detect whether the “select-it” button  66  or some other button or transducer has been activated to indicate a desire to see an area of importance image.  
      In another embodiment, the mode selection determination (step  158 ) is performed automatically. For example, camera controller  32  and/or signal processor  28  can examine camera conditions at the time that an archival image is captured and/or examine the archival image and determine that there is a possibility based upon such examinations that the area of importance in the archival image might not have an appearance that is acceptable. When such conditions are detected controller  32  automatically selects area of importance image display mode.  
      When an area of importance image display mode has been selected, the area of importance is determined for the archival image using any of the methods identified above (step  160 ). An area of importance image is then formed as described above (step  162 ) and is resampled for presentation. This area of importance image is presented (step  164 ) for a period of time (step  166 ). After the area of importance image has been presented, the presentation can end.  
      However, in one alternate embodiment shown in dashed lines in  FIG. 8 , after the area of importance image has been presented for a period of time on display  30 , the evaluation image can again be displayed (step  168 ) in order to provide context for the area of importance image. The display of the evaluation image is then discontinued after a display period (step  170 ).  
      As described above, the image information used to form the area of importance image is resampled for presentation on an area that occupies a larger proportion of the imaging area of display  30  than the area of importance occupies when the evaluation image is displayed.  
      Accordingly, the area of importance image shows the area of importance with greater apparent magnification than the evaluation image shows the same area. The resampling is done so that the area of focus image shows the area of focus in greater detail than the area of importance will appear in the archival image. By providing such an area of importance image automatically to a user the user can more efficiently evaluate important areas of the captured archival image and to make meaningful decisions about using the image or capturing another.  
      In one embodiment the area of importance image can be resampled so that it is sized to occupy an entire display area of display  30 . An example of this is illustrated in  FIG. 6 .  
      In other embodiments, the area of importance image is resampled so that it too uses only a portion of the available display area of display  30 . For example, the area of importance image can be used to provide a thumbnail type image.  FIGS. 9   a ,  9   b , and  9   c  each show an archival image, images  180 ,  182 , and  184  each having an area of importance  186 ,  188 , and  190  respectively.  FIG. 10  shows a thumbnail listing  192  of evaluation images  181 ,  183 , and  185  that correspond respectively to archival images  180 ,  182 , and  184 . This is known in the art.  
       FIG. 11  shows a thumbnail listing  194  of area of importance images  196 ,  198 , and  200  that are obtained from areas of importance  186 ,  188 , and  190  respectively. It will be appreciated that the image content of area of importance thumbnail evaluation images  196 ,  198 , and  200  are more easily evaluated.  
       FIG. 12  shows an example embodiment of a combined display of an evaluation image  200  and an area of importance image  202 . In  FIG. 12 , the area of importance image  202  is resampled so that it has greater apparent magnification than evaluation image  200 , however it is also sampled to a size that allows a user to view an evaluation image  202  and the area of importance  204  image concurrently so that the user has the opportunity to understand that the area of importance image in context with the evaluation image. As is shown in  FIG. 12 , during the time that the area of importance image  200  is presented, the area of importance image  202  is presented as in insert in evaluation image  200 . A border  204  separates the images.  
       FIG. 13 , shows another example embodiment of a combined display of an evaluation image and an area of importance image. In this embodiment, border  206  is provided that has the appearance of a magnifying glass or some other useful iconic symbol to indicate that the region being observed is being viewed in an enlarged form.  
      The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.  
     Parts List  
     
         
           10  display device  
           12  digital camera  
           20  body  
           22  image capture system  
           23  lens system  
           24  image sensor  
           25  lens driver  
           26  signal processor  
           27  rangefinder  
           28  display driver  
           30  display  
           32  controller  
           34  user input system  
           36  sensors  
           40  memory  
           46  memory card slot  
           48  removable memory  
           50  memory interface  
           52  remote memory  
           54  communication module  
           38  viewfinder  
           60  capture button  
           62  wide button  
           64  tele button  
           66  joystick  
           67  mode button  
           68  select-it button  
           100  obtain archival image step  
           102  determine area of importance step  
           104  form area of importance image step  
           106  present area of importance image  
           108  provide warning  
           110  scene  
           112  focus region  
           114  focus region  
           116  focus region  
           118  evaluation image  
           120  area of importance  
           121  area of importance template  
           122  area of importance image  
           130  capture set of preview evaluation images step  
           132  capture archival image step  
           134  form evaluation image step  
           136  identify common portions step  
           138  generate area importance date identifying portion of archival image having identified common portions step  
           140  associate area importance data with archival image step  
           142  use area importance data to identify image content within archival image that corresponds to area of importance step  
           150  obtained archival image step  
           152  form evaluation image step  
           154  present evaluation image step  
           156  display period over determining step  
           158  area of importance mode determining step  
           160  area of importance determining step  
           162  form area of importance image step  
           164  present area importance image  
           166  presentation period over determining step  
           168  display evaluation image step  
           170  display period over determining step  
           180  archival image  
           181  evaluation image  
           182  archival image  
           183  evaluation image  
           184  archival image  
           185  evaluation image  
           186  area of importance  
           188  area of importance  
           190  area of importance  
           192  thumbnail listing of archival images  
           194  for thumbnail listing area importance images  
           196  area of importance image  
           198  area of importance image  
           200  evaluation image  
           202  area of importance image  
           204  border  
           206  border