Patent Publication Number: US-2007097252-A1

Title: Imaging methods, cameras, projectors, and articles of manufacture

Description:
FIELD OF THE DISCLOSURE  
      Aspects of the disclosure relate to imaging methods, cameras, projectors, and articles of manufacture.  
     BACKGROUND OF THE DISCLOSURE  
      Numerous advancements have been made recently with respect to imaging devices and methods. For example, image sensors in digital cameras have been fabricated which capture images at increased resolutions and projectors have been similarly improved to project images at increased resolutions. The increased ease, quality and flexibility of digital representations of images have led to increased popularity of digital imaging systems.  
      Other aspects of digital imaging systems have also been improved or enhanced to provide users with suitable alternatives to film based imaging systems. For example, in addition to higher resolutions attainable with recent digital devices, image processing algorithms such as color balancing have also been improved to increase the ability of digital imaging systems to capture and generate images which more closely represent a received image of a scene in camera applications or project images which more closely represent an inputted image for display.  
      At least some aspects of the disclosure provide improved systems and methods for generating images.  
     SUMMARY  
      According to some aspects of the disclosure, exemplary imaging methods, cameras, projectors, and articles of manufacture are described.  
      According to one embodiment, an imaging method comprises providing light of a plurality of regions of an input image, associating light of an individual one of the regions of the input image with a plurality of spatially separated regions, wherein the light of one of the regions of the input image comprises a plurality of wavelengths of light and wherein the spatially separated regions which correspond to the one region of the input image individually comprise light of a respective individual wavelength of the light present in the one region of the input image, providing a plurality of electrical signals, wherein respective ones of the electrical signals correspond to respective ones of the spatially separated regions and respective ones of the different wavelengths of light, and wherein the light of one of the spatially separated regions is substantially all of the light of the respective wavelength of the light of the one region of the input image.  
      According to another embodiment, a camera comprises an optical system configured to receive a plurality of different wavelengths of light of an input image and to generate a plurality of light beams using the light of the input image and comprising respective ones of the wavelengths of light, wherein the generation of the light beams comprises separating the light of the input image into the light beams corresponding to a plurality of spatially separated regions, and an image generation device optically coupled with the optical system and configured to receive the light beams at the spatially separated regions and to generate image data of a representation of the input image using the light of the received light beams, wherein the light beams received by the image generation device comprise substantially an entirety of the light of the respective wavelengths of light of the input image received by the camera.  
      Other embodiments are described as is apparent from the following discussion. 
    
    
     DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a functional block diagram of an imaging device according to one embodiment.  
       FIG. 2  is a functional block diagram of an imaging system of an imaging device according to one embodiment.  
       FIGS. 3A-3B  are illustrative representations of imaging systems according to exemplary embodiments.  
       FIG. 4  is an illustrative representation of an image generated according to at least one embodiment.  
       FIG. 5  is a flow chart of an exemplary imaging method according to one embodiment.  
    
    
     DETAILED DESCRIPTION  
      At least some aspects of the disclosure provide imaging devices and methods in digital embodiments as well as film based embodiments. Some embodiments of the devices and methods provide image capture operations or image projection operations, or both. Aspects of the disclosure describe imaging devices and imaging methods which may use chromatic dispersion according to some embodiments. According to at least some exemplary camera configurations, aspects of the disclosure provide devices and methods of increased sensitivity to received light compared with some other camera configurations. Other image capture and projection aspects are described below.  
       FIG. 1  shows one embodiment of an imaging device  10 . Imaging device  10  may be configured to capture images of scenes in camera embodiments or output images in projector embodiments. In the depicted illustration, image device  10  includes a communications interface  12 , processing circuitry  14 , storage circuitry  16 , an imaging system  18  and a user interface  20 . Other configurations of imaging device  10  may be provided including more, less or alternative components.  
      Communications interface  12  is arranged to implement communications of imaging device  10  with respect to external devices not shown. Communications interface  12  may be implemented as a network interface card (NIC), serial or parallel connection, USB port, Firewire interface, flash memory interface, floppy disk drive, or any other suitable arrangement for communications. Communications interface  12  may be configured to output image data used to generate representations of captured images, to receive image data to be projected, and to communicate other data or information.  
      In one embodiment, processing circuitry  14  is arranged to process data, control data access and storage, issue commands, and control other desired operations of imaging device  10 . Processing circuitry  14  may comprise circuitry configured to implement desired programming provided by appropriate media in at least one embodiment. For example, the processing circuitry may be implemented as one or more of a processor or other structure configured to execute executable instructions including, for example, software or firmware instructions, or hardware circuitry. Exemplary embodiments of processing circuitry include hardware logic, PGA, FPGA, ASIC, state machines, or other structures alone or in combination with a processor. These examples of processing circuitry are for illustration and other configurations are possible.  
      Processing circuitry  14  may be configured to process image data captured responsive to received light, generate image data to be projected by the imaging device  10  and perform other operations with respect to image capture and projection. Plural processing circuits  14  may be provided in some embodiments. For example, one processor may be implemented within a housing of a camera or a projector while another processor (e.g., in a personal computer) may be provided externally of the camera or projector. At least some of the operations of processing circuitry  14  described herein may be split between plural processors in one embodiment.  
      The storage circuitry  16  is configured to store electronic data and programming such as executable code or instructions (e.g., software, firmware), databases, or other digital information and may include processor-usable media. Storage circuitry  16  may be configured to store image data of captured, images and buffer image data to be projected by imaging device  10 .  
      Processor-usable media includes any article of manufacture  17  (e.g., computer program product) which can contain, store, or maintain programming, data and digital information for use by or in connection with an instruction execution system including processing circuitry in the exemplary embodiment. For example, exemplary processor-usable media may include any one of physical media such as electronic, magnetic, optical, electromagnetic, infrared or semiconductor media. Some more specific examples of processor-usable media include, but are not limited to, a portable magnetic computer diskette, such as a floppy diskette or zip disk, hard drive, random access memory, read only memory, flash memory, cache memory, and other configurations capable of storing programming, data, or other digital information.  
      At least some embodiments or aspects described herein may be implemented using programming stored within appropriate storage circuitry  16  described above or communicated via an appropriate transmission medium. For example, programming may be provided via appropriate media including for example articles of manufacture  17  described above, or embodied within a data signal (e.g., modulated carrier wave, data packets, digital representations, etc.) communicated via an appropriate transmission medium. Exemplary transmission media include a communication network (e.g., the Internet, a private network, etc.), wired electrical connection, optical connection and electromagnetic energy. Signals containing programming may be communicated for example via communications interface  12 , or propagated using other appropriate communication structure or medium. Exemplary programming including processor-usable code may be communicated as a data signal embodied in a carrier wave in but one example.  
      Imaging system  18  may be configured to receive and capture light of images and to project images. Imaging system  18  may include a plurality of optical-electrical devices configured to associate respective electrical signals with captured light or projected light. Additional details regarding exemplary configurations of imaging system  18  are described below.  
      User interface  20  is configured to interact with a user including conveying data to a user (e.g., displaying data for observation by the user, audibly communicating data to a user, etc.) as well as receiving inputs from the user (e.g., tactile input, voice instruction, etc.). Accordingly, in one exemplary embodiment, the user interface  20  may include a display  22  (e.g., cathode ray tube, LCD, etc.) configured to depict visual information as well as input keys or other input device. Any other suitable apparatus for interacting with a user may also be utilized.  
      Referring to  FIG. 2 , a configuration of imaging system  18  is shown according to one embodiment. The illustrated imaging system  18  includes an optical system  30  optically coupled with an image generation device  32 . Imaging systems  18  of  FIG. 2  may be implemented in camera or projector embodiments. In camera embodiments, optical system  30  is configured to receive light  31  of images of a scene to be captured, referred to as input images or received images. In projector embodiments, optical system  30  is configured to emit light  31  of projected images.  
      Optical system  30  is configured to implement focusing operations during image capture or image projection. For example, optical system  30  may focus light  31  (e.g., received by imaging device  10 , emitted from imaging device  10 ) with respect to image generation device  32 . As discussed further below, optical system  30  is optically coupled with image generation device  32  and may communicate a plurality of light beams  38  therebetween. Additional details of possible optical systems  30  are discussed below with respect to the exemplary embodiments of  FIGS. 3A and 3B .  
      Image generation device  32  may be configured to generate image data of images responsive to received light in camera embodiments or emit light responsive to received image data in projector embodiments. Image generation device  32  may include an array  34  of imaging elements  36  provided in a focal plane of imaging device  10  in exemplary embodiments. Imaging elements  36  may comprise optical-electrical devices configured to generate electrical signals responsive to received light or emit light responsive to received electrical signals wherein the electrical signals may correspond to generated or received image data in respective exemplary embodiments. In other embodiments, the array  34  of imaging elements  36  may be replaced by a film.  
      Imaging elements  36  may be arranged in a plurality of pixel locations of array  34  comprising a two-dimensional array having a plurality of orthogonal parallel lines (i.e., rows and columns) in at least one configuration (only imaging elements  36  extending in the x direction are shown in the illustrative embodiments of  FIGS. 2, 3A  and  3 B although imaging elements  36  are also provided in the y direction in one embodiment). Imaging elements  36  are optically coupled with respective ones of the light beams  38  which individually include different wavelengths of light (e.g., imaging elements  36   a ,  36   b ,  36   c  may be positioned to receive red, green and blue light, respectively, in an exemplary RGB embodiment). Although light beams  38  may individually include a single peak wavelength of light, other wavelengths of light near the peak wavelength may also be present in the light beams  38  in some embodiments. Other embodiments in addition to RGB are possible for example including less colors or more colors (e.g., in a hyperspectral camera).  
      Imaging elements  36  may comprise light sensing devices (e.g., CMOS or CCDs) or light emitting devices (e.g., light emitting diodes) which correspond to a plurality of pixel locations in exemplary image capture and projection embodiments, respectively. As discussed further below with respect to exemplary embodiments of the disclosure, imaging elements  36  may be configured to receive light or emit light of light beams  38  depending upon the implementation of imaging system  18  in a camera application or a projector application.  
      In some embodiments of imaging device  10  configured to implement both image capture and projection operations, two imaging systems  18  illustrated in  FIG. 2  may be provided and individually configured to implement one of image capture or projection.  
      Referring to  FIGS. 3A-3B , exemplary configurations of optical systems  30 ,  30   a  and image generation device  32  are shown in respective illustrative embodiments. The illustrated optical systems  30 ,  30   a  each include a lens system  50  and a dispersive element  52  optically coupled with one another. The lens system  50  may be spaced a distance from array  34  substantially equal to a focal length of lens system  50  in one embodiment. In  FIGS. 3A and 3B , the positioning of lens systems  50  and dispersive elements  52  are reversed with respect to one another. The lens system  50  is configured as a lenticular array comprising a plurality of lens elements  54  embodied as semi-cylindrical lenslets in the illustrative embodiments. In some camera embodiments, a lenticular array spreads an input image into spectra including a plurality of lines and the strength of light may be sensed at various points along the spectrum for example using a broad-spectrum light sensor and a full color representation of the input image may be reconstructed as described below. Other embodiments of lens system  50  are possible including a relay lens which may provide additional room for the dispersive element  52  enabling the provision of spectra of increased size.  
      Referring to  FIG. 3A , image capture operations of imaging system  18  are described hereafter with respect to exemplary camera embodiments. Individual ones of the lens elements  54  outputs a respective light beam  60  responsive to received light  31  ( FIG. 2 ) which may include a plurality of different wavelengths of light of an input image. The light beams  60  are received by dispersive element  52  which separates (e.g., splits) the light of a respective light beam  60  into plural light beams  38   a ,  38   b ,  38   c  which are received by respective imaging elements  36   a ,  36   b ,  36   c . Dispersive element  52  may be implemented as a holographic film, diffraction grating, prism, or other configuration to split received light of light beam  60  into its respective wavelength components. In the illustrated embodiment, dispersive element  52  splits each of the light beams  60  into plural light beams  38   a ,  38   b ,  38   c  including the respective component wavelengths of the respective light beams  60 . As mentioned above, individual light beams  38   a ,  38   b ,  38   c  may include single peak wavelengths of light such as red, green or blue in the embodiments of  FIGS. 3A and 3B . The respective light beams  38   a ,  38   b ,  38   c  may also include other wavelengths of light spectrally adjacent red, green or blue (i.e., light beams  38   a ,  38   b ,  38   c  may include different wavelengths of the spectrum). As shown, the light beams  38   a ,  38   b ,  38   c  correspond to a plurality of spatially separated regions of image generation device  32  corresponding respective imaging elements  36   a ,  36   b ,  36   c . In one embodiment, the imaging elements  36   a ,  36   b ,  36   c  individually only receive substantially one peak wavelength of light corresponding to the respective wavelengths of light of the light beams  38   a ,  38   b ,  38   c  (e.g., red, green or blue). In other embodiments, the lens system  50  or array  34  may be moved with respect to the other such that imaging elements  36   a ,  36   b ,  36  may correspond to other wavelengths of light of the visible spectrum, for example, for use in 2D spectrophotometry providing wide color gamut images.  
      As mentioned above, the imaging elements  36   a ,  36   b ,  36   c  may be arranged in a two-dimensional array  34  and additional elements  36  (not shown) may be provided in the z-axis direction. For example, the imaging elements  36   a ,  36   b ,  36   c  may be arranged in a plurality of respective columns which extend in the z-axis direction of  FIG. 3A  in one arrangement. In addition, imaging elements  36   a ,  36   b ,  36   c  may be arranged in a plurality of groups  40 . Groups  40  may individually include one of each of imaging elements  36   a ,  36   b ,  36   c  in a common row (x-axis direction) and receive light of the visible spectrum (e.g., red, green and blue light), respectively. As described further below, light received by imaging elements  36   a ,  36   b ,  36   c  of groups  40  may be combined to form respective regions of a representation of the input image. Regions of the representation of the input image may correspond to light combined from groups  40  of imaging elements or groups of parallel lines of imaging elements  36  and include light in the form of stripes corresponding to respective regions of the wavelengths.  
      In the example of  FIG. 3A , respective groups  40  receive light of a plurality of respective regions of the received or input image. For example, some regions of the received image may correspond in one example to areas of light received by respective lenslets of the optical system  30  in one example. These regions may be individually defined by a distance in the x-axis dimension equal to the width (e.g., diameter) of the corresponding lens element  54  and a distance in the z-axis direction corresponding to the size of the imaging elements  36  in the z-axis direction. Other regions of the input image may be defined, for example, individually extending further in the z-axis direction (e.g., the entire length of the array  34  in the z-axis direction in one embodiment). Individual ones of the regions of the input image include a plurality of wavelengths of light corresponding to the beams  38   a ,  38   b ,  38   c  for the respective region.  
      In the described configurations of  FIGS. 3A and 3B , imaging elements  36   a ,  36   b ,  36   c  receive substantially an entirety of the light of the respective wavelengths for the respective regions of the received image Light beams  38   a ,  38   b ,  38   c  include substantially an entirety of the light of the respective wavelengths received by the corresponding lens element  54  and no filtering of the light, such as Bayer-Mosaic filtering, is implemented by imaging system  18  in one embodiment. Substantially an entirety of the light of the input image received by optical system  30  is collectively received by all of the imaging elements  36  of the image generation device  32  in one embodiment. Imaging elements  36   a ,  36   b ,  36   c  output electrical signals corresponding to the respective wavelengths of light and which may be used by processing circuitry  14  or other circuitry to provide digital image data of a representation of the received image.  
      In a projector implementation of  FIG. 3A , imaging elements  36   a ,  36   b ,  36   c  may be configured to emit light beams  38   a ,  38   b ,  38   c  including light of red, green and blue, respectively. Emitted light beams  38   a ,  38   b ,  38   c , may form an input image in projector embodiments. For example, processing circuitry  14  may access digital image data and provide electrical signals to imaging elements  36   a ,  36   b ,  36   c  to generate images responsive to the image data. The dispersive element  52  combines the light of light beams  38   a ,  38   b ,  38   c  into light beams  60  which are magnified and projected by lens system  50  as an appropriate projected image responsive to the received light of light beams  38   a ,  38   b ,  38   c.    
      Groups  40  of imaging elements  36  configured as light emitting devices are configured to generate light for a respective region of the output image similar to the regions of the input image described above. Optical system  30  may combine light beams  38   a ,  38   b ,  38   c  emitted from one of the groups  40  of imaging elements  36  to generate a respective region of the output image in one embodiment.  
      Referring to the exemplary embodiment of  FIG. 3B  with respect to a camera implementation, dispersive element  52  of optical system  30   a  receives light and splits the light into a plurality light beams  62  corresponding to the chromatic components of the received light  31 . Len system  50  receives the light beams  62  and focuses a plurality of corresponding light beams  38   a ,  38   b ,  38   c  to respective imaging elements  36   a ,  36   b ,  36   c  which may generate image data responsive to the received light.  
      In a projector implementation of  FIG. 3B , imaging elements  36   a ,  36   b ,  36   c  configured as light emitting devices emit light beams  38   a ,  38   b ,  38   c  responsive to control by processing circuitry  14 . The light beams  38   a ,  38   b ,  38   c  are received by lens system  50  of optical system  30   a . Lens system  50  magnifies and outputs a plurality of light beams  62  corresponding to the wavelengths of light of light beams  38   a ,  38   b ,  38   c . Dispersive element  52  receives and combines the light beams  62  to project an output image corresponding to the received light.  
      Referring to  FIG. 4 , an exemplary representation  70  of an input image received by imaging device  10  is shown. Representation  70  includes a plurality of groups  72  of parallel lines  74  (e.g., stripes) forming rows. The rows correspond to columns of image data provided by imaging elements  36  described with respect to  FIGS. 3A-3B  and groups  72  correspond to columns of groups  40  of imaging elements  36  of  FIGS. 3A-3B  in the described embodiment. In an exemplary RGB implementation, individual ones of the rows of the groups  72  correspond to one of three color planes (i.e., red, green or blue) in an exemplary RGB configuration. Accordingly, groups  72  may include a plurality of repetitive RGB stripes corresponding to respective lens elements  54  in one embodiment.  
      Processing circuitry  14  or other circuitry may process the image data corresponding to the rows of  FIG. 4  to generate a more accurate representation of the input image compared with representation  70  which is provided to illustrate operational aspects of one possible implementation of imaging device  10 . According to one embodiment, processing circuitry  14  may spatially and chromatically combine the image data by superimposing the image data of the respective rows of individual groups  72  over one another to generate a continuous full color image representation of the input image. More specifically, for a given group  72 , the processing circuitry  14  may combine the red, green and blue image data of the respective rows of the given group to form a full color parallel line of the continuous full color image representation. Other processing embodiments are possible.  
      Referring to  FIG. 5 , an exemplary method is shown for generating images according to one embodiment. Other methods are possible including more, less or alternative steps.  
      At a step S 10 , light is received by imaging device  10  and focused by the lens system. In one embodiment, the received light corresponds to light  31  of  FIG. 2 .  
      At a step S 12 , received light is split into a plurality of light beams individually comprising spectral bands of light. The light beams may include different wavelengths of light in one embodiment. For example, the light beams may individually include one of red, green or blue light (and wavelengths spectrally adjacent thereto) in one embodiment.  
      At a step S 14 , the light beams are received by respective imaging elements.  
      At a step S 16 , the light beams are captured by the imaging elements. For example, in one embodiment, a plurality of electrical signals indicative of intensity of the respective light beams may be generated to capture the light beams.  
      At least some aspects of the disclosure are believed to be useful in relatively high resolution implementations (e.g., megapixels) where sensitivity may be more useful or important than resolution (e.g., high resolution cameras having a small fillfactor). For example, at least some of the described embodiments provide devices of increased sensitivity (i.e., approximately three times) compared with configurations which filter approximately two thirds of the light and implement demosaicing to generate full color images. Aspects of the commonly assigned co-pending U.S. patent application entitled “Imaging Apparatuses, Image Data Processing Methods, and Articles of Manufacture,” naming Amnon Silverstein as inventor, filed Oct. 31, 2003, having Ser. No. 10/698,926, and the teachings of which are incorporated by reference, may be utilized recapture or increase the spatial resolution of images.  
      The protection sought is not to be limited to the disclosed embodiments, which are given by way of example only, but instead is to be limited only by the scope of the appended claims.