Stereographic image compression with image moment normalization

• US 6,275,253 B1
• Filed: 07/09/1998
• Issued: 08/14/2001
• Est. Priority Date: 07/09/1998
• Status: Expired due to Term

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Melen, Roger D.
• Primary Examiner(s): Brier, Jeffery
• Assistant Examiner(s): YANG, RYAN R
• Application Number:
  US09/113,937
• Time in Patent Office: 1,132 Days
• Field of Search: 348/42, 348/43, 348/384, 348/390, 382/298, 382/232, 382/154, 345/127
• US Class Current: 348/43
• CPC Class Codes: H04N 13/111 Transformation of image signals corresponding to virtual viewpoints, e.g. spatial image interpolation
• CPC Class Codes: H04N 13/133 Equalising the characteristics of different image components, e.g. their average brightness or colour balance
• CPC Class Codes: H04N 13/161 Encoding, multiplexing or demultiplexing different image signal components for multi-view video sequence encoding H04N19/597
• CPC Class Codes: H04N 13/167 Synchronising or controlling image signals
• CPC Class Codes: H04N 13/189 Recording image signals; Reproducing recorded image signals
• CPC Class Codes: H04N 13/194 Transmission of image signals
• CPC Class Codes: H04N 13/239 using two 2D image sensors having a relative position equal to or related to the interocular distance H04N13/243 takes precedence
• CPC Class Codes: H04N 13/296 Synchronisation thereof; Control thereof
• CPC Class Codes: H04N 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• CPC Class Codes: H04N 19/597 specially adapted for multi-view video sequence encoding
• CPC Class Codes: H04N 2013/0081 Depth or disparity estimation from stereoscopic image signals

Abstract

A stereographic image compressor (100) includes an Image Size and Position Unit (ISPU) (101) that resizes and repositions a pair of images which are indicative, respectively, of first and second fields of view (111, 114) of an image (104) and which are generated by a pair of image sensor arrays (106, 108). The ISPU (101) causes both images to have a same size and position. The ISPU (101) generates a first modified image signal (103) and a second modified image signal (105) indicative of such resized and repositioned images. A function processing unit (118) generates a difference signal (120) indicative of differences between the first modified image signal (103) and the second modified image signal (105) The difference signal (120) is compressed by a lossy compressor (122) for storage on a storage device (102). The first modified image signal (103) is also compressed by a lossy compressor (124) for storage on the storage device (102). The image signals (110 and 112) are time synchronized by an image data synchronizer (116). The function processing unit (118) generates difference signal (120) by way of one of a plurality of mathematical operations.

Claims

1. A stereographic image compressor comprising:

an image size and position unit, responsive to a first image signal containing image information of a scene from a first field of view, and a second image signal containing image information of said scene from a second field of view, for selectively resizing and repositioning said images represented by said first and said second image signals based upon input from a user, to generate a modified first image signal and a modified second image signal, said modified first image signal and said modified second image signal each characterized by a same size and position;

a function processing unit, having a plurality of modes selectable by said user, responsive to said modified first image signal and said modified second image signal, for generating a difference image signal, indicative of differences between said modified first image signal and said modified second image signal; and

a lossy compressor, responsive to said difference image signal, for compressing image information contained in said difference image signal, to generate a compressed image information signal.

2. A stereographic image compressor as set forth in claim 1 wherein said image size and position unit further generates size and position modification information indicative of a first difference between said modified first image signal and said first image signal and indicative of a second difference between said modified second image signal and said second image signal.

3. A stereographic image compressor as set forth in claim 2 further comprising a storage device for storing said compressed image information signal, said modified first image signal and said size and position modification information.

4. A stereographic image compressor as set forth in claim 3 further comprising a synchronizer for causing said first image signal and said second image signal to be time synchronized.

5. A stereographic image compressor as set forth in claim 1 further comprising a storage device for storing said compressed image information signal and said modified first image signal.

6. A stereographic image compressor as set forth in claim 1 further comprising a synchronizer for causing said first image signal and said second image signal to be time synchronized.

7. Apparatus for resizing and repositioning image data taken of a similar field of view from two different locations, said apparatus comprising:

synchronizing means, responsive to a pair of image signals, comprising a first image signal containing image information corresponding to a first of said two locations and a second image signal containing image information corresponding to a second of said two locations, for time synchronizing said first image signal with said second image signal;

image size and position means, responsive to said synchronizing means, and reconfigurable in response to commands provided by a user, for modifying said first image signal and said second image signal to generate a modified first image signal and a modified second image signal, said first and second modified image signals being characterized by a single size and position of said field of view;

difference generation means, responsive to said image size and position means, and reconfigurable in response to commands provided by said user, for generating a difference signal, indicative of differences between said first and said second modified image signals; and

lossy compressor means, responsive to said difference generation means, for compressing said difference signal.

8. A method for compressing stereographic image data, said method comprising:

generating a first image signal indicative of a first field of view of an image;

generating a second image signal indicative of a second field of view of an image;

modifying said first image signal and said second image signal reconfigurably in response to commands introduced by a user to generate a modified first image signal and a modified second image signal, said first field of view represented by said first image signal being equal in size and position to said second field of view represented by said second image signal;

in response to commands introduced by said user, reconfigurably generating a difference signal indicative of differences in images indicated by said modified first image signal and said modified second image signal;

performing lossy compression on said difference signal to generate a compressed difference signal and performing lossy compression on said modified first image signal to generate a first compressed image signal; and

causing storage of said compressed difference signal and said first compressed image signal to a storage device.

9. A method as set forth in claim 8 further comprising the step of generating a size and position modification signal indicative of a difference between said first image signal and said modified first image signal and indicative of a difference between said second image signal and said modified second image signal.

10. A method as set forth in claim 9 further comprising the step of causing storage of said size and position modification signal to said storage device.

11. A computer readable storage medium comprising a stereographic image compressor, comprising:

an image size and position unit, reconfigurably responsive to command signals emanating from a user and responsive to a first image signal containing image information of a scene from a first field of view, and a second image signal containing image information of said scene from a second field of view, for resizing and repositioning said images represented by said first and said second image signals to generate a modified first image signal and a modified second image signal, said modified first image signal and said modified second image signal each characterized by a same size and position;

a function processing unit, reconfigurably responsive to command signals emanating from said user and responsive to said modified first image signal and said modified second image signal, for generating a difference image signal, indicative of differences between said modified first image signal and said modified second image signal; and

a lossy compressor, responsive to said difference image signal, for compressing image information contained in said difference image signal, to generate a compressed image information signal.

12. A stereographic image compressor comprising:

an image size and position unit, responsive to a first image signal containing image information of a scene from a first field of view, and a second image signal containing image information of said scene from a second field of view, for selectively resizing and repositioning said images represented by said first and said second image signals based upon input from a user, to generate a modified first image signal and a modified second image signal, said modified first image signal and said modified second image signal each characterized by a same size and position;

a function processing unit, having a plurality of modes selectable by said user, responsive to said modified first image signal and said modified second image signal, for generating a difference image signal, indicative of differences between said modified first image signal and said modified second image signal; and

a lossy compressor, responsive to said difference image signal, for compressing image information contained in said difference image signal, to generate a compressed image information signal;

wherein the resizing and repositioning of the images are selectable by the user based upon at least one of image compressability considerations, trial and error, and image quality considerations.

13. A stereographic image compressor comprising:

an image size and position unit, responsive to a first image signal containing image information of a scene from a first field of view, and a second image signal containing image information of said scene from a second field of view, for selectively resizing and repositioning said images represented by said first and said second image signals based upon input from a user, to generate a modified first image signal and a modified second image signal, said modified first image signal and said modified second image signal each characterized by a same size and position;

a function processing unit, having a plurality of modes selectable by said user, responsive to said modified first image signal and said modified second image signal, for generating a difference image signal, indicative of differences between said modified first image signal and said modified second image signal; and

a lossy compressor, responsive to said difference image signal, for compressing image information contained in said difference image signal, to generate a compressed image information signal;

wherein the modes of the function processing unit comprise at least one of the following;

the modified first image signal and the modified second image signal are each scaled by constants, creating two new signals which are subtracted from each other and augmented by the addition of an offset;

the modified first image signal and the modified second image signal are each gamma corrected by exponential values, creating two gamma corrected signals which are subtracted from each other; and

the modified first image signal and the modified second image signal are each augmented by the addition of constants, creating two resulting signals which are divided then augmented by the addition of a constant.

14. Apparatus for resizing and repositioning image data taken of a similar field of view from two different locations, said apparatus comprising:

synchronizing means, responsive to a pair of image signals, comprising a first image signal containing image information corresponding to a first of said two locations and a second image signal containing image information corresponding to a second of said two locations, for time synchronizing said first image signal with said second image signal;

image size and position means, responsive to said synchronizing means, and reconfigurable in response to commands provided by a user, for modifying said first image signal and said second image signal to generate a modified first image signal and a modified second image signal, said first and second modified image signals being characterized by a single size and position of said field of view;

difference generation means, responsive to said image size and position means, and reconfigurable in response to commands provided by said user, for generating a difference signal, indicative of differences between said first and said second modified image signals; and

lossy compressor means, responsive to said difference generation means, for compressing said difference signal;

wherein said reconfigurable image size and position means has at least one of the following modes;

a mode based upon image compressibility considerations;

a mode based upon trial and error; and

a mode based upon image quality considerations.

15. Apparatus for resizing and repositioning image data taken of a similar field of view from two different locations, said apparatus comprising:

synchronizing means, responsive to a pair of image signals, comprising a first image signal containing image information corresponding to a first of said two locations and a second image signal containing image information corresponding to a second of said two locations, for time synchronizing said first image signal with said second image signal;

image size and position means, responsive to said synchronizing means, and reconfigurable in response to commands provided by a user, for modifying said first image signal and said second image signal to generate a modified first image signal and a modified second image signal, said first and second modified image signals being characterized by a single size and position of said field of view;

difference generation means, responsive to said image size and position means, and reconfigurable in response to commands provided by said user, for generating a difference signal, indicative of differences between said first and said second modified image signals; and

lossy compressor means, responsive to said difference generation means, for compressing said difference signal;

wherein the difference generation means is reconfigurable to exhibit at least one of the following characteristics;

the modified first image signal and the modified second image signal are each scaled by constants, creating two new signals which are subtracted from each other and augmented by the addition of an offset;

the modified first image signal and the modified second image signal are each gamma corrected by exponential values, creating two gamma corrected signals which are subtracted from each other; and

the modified first image signal and the modified second image signal are each augmented by the addition of constants, creating two resulting signals which are divided then augmented by the addition of a constant.

16. A method for compressing stereographic image data, said method comprising:

generating a first image signal indicative of a first field of view of an image;

generating a second image signal indicative of a second field of view of an image;

modifying said first image signal and said second image signal reconfigurably in response to commands introduced by a user to generate a modified first image signal and a modified second image signal, said first field of view represented by said first image signal being equal in size and position to said second field of view represented by said second image signal;

in response to commands introduced by said user, reconfigurably generating a difference signal indicative of differences in images indicated by said modified first image signal and said modified second image signal;

performing lossy compression on said difference signal to generate a compressed difference signal and performing lossy compression on said modified first image signal to generate a first compressed image signal; and

causing storage of said compressed difference signal and said first compressed image signal to a storage device;

wherein the step of modifying said first image signal and said second image signal reconfigurably takes into account at least one of image compressibility considerations, trial and error, and image quality considerations.

17. A method for compressing stereographic image data, said method comprising:

generating a first image signal indicative of a first field of view of an image;

generating a second image signal indicative of a second field of view of an image;

modifying said first image signal and said second image signal reconfigurably in response to commands introduced by a user to generate a modified first image signal and a modified second image signal, said first field of view represented by said first image signal being equal in size and position to said second field of view represented by said second image signal;

in response to commands introduced by said user, reconfigurably generating a difference signal indicative of differences in images indicated by said modified first image signal and said modified second image signal;

performing lossy compression on said difference signal to generate a compressed difference signal and performing lossy compression on said modified first image signal to generate a first compressed image signal; and

causing storage of said compressed difference signal and said first compressed image signal to a storage device;

wherein the step of reconfigurably generating a difference signal is performed using one of the following techniques;

the modified first image signal and the modified second image signal are each scaled by constants, creating two new signals which are subtracted from each other and augmented by the addition of an offset;

the modified first image signal and the modified second image signal are each gamma corrected by exponential values, creating two gamma corrected signals which are subtracted from each other; and

the modified first image signal and the modified second image signal are each augmented by the addition of constants, creating two resulting signals which are divided then augmented by the addition of a constant.

18. A computer readable storage medium comprising a stereographic image compressor, comprising:

an image size and position unit, reconfigurably responsive to command signals emanating from a user and responsive to a first image signal containing image information of a scene from a first field of view, and a second image signal containing image information of said scene from a second field of view, for resizing and repositioning said images represented by said first and said second image signals to generate a modified first image signal and a modified second image signal, said modified first image signal and said modified second image signal each characterized by a same size and position;

a function processing unit, reconfigurably responsive to command signals emanating from said user and responsive to said modified first image signal and said modified second image signal, for generating a difference image signal, indicative of differences between said modified first image signal and said modified second image signal; and

a lossy compressor, responsive to said difference image signal, for compressing image information contained in said difference image signal, to generate a compressed image information signal;

wherein the image size and position unit is reconfigurable based upon at least one of image compressibility considerations, trial and error, and image quality considerations.

19. A computer readable storage medium comprising a stereographic image compressor, comprising:

an image size and position unit, reconfigurably responsive to command signals emanating from a user and responsive to a first image signal containing image information of a scene from a first field of view, and a second image signal containing image information of said scene from a second field of view, for resizing and repositioning said images represented by said first and said second image signals to generate a modified first image signal and a modified second image signal, said modified first image signal and said modified second image signal each characterized by a same size and position;

a function processing unit, reconfigurably responsive to command signals emanating from said user and responsive to said modified first image signal and said modified second image signal, for generating a difference image signal, indicative of differences between said modified first image signal and said modified second image signal; and

a lossy compressor, responsive to said difference image signal, for compressing image information contained in said difference image signal, to generate a compressed image information signal;

wherein the function processing unit is reconfigurable to operate in at least one of the following modes;

the modified first image signal and the modified second image signal are each scaled by constants, creating two new signals which are subtracted from each other and augmented by the addition of an offset;

the modified first image signal and the modified second image signal are each gamma corrected by exponential values, creating two gamma corrected signals which are subtracted from each other; and

the modified first image signal and the modified second image signal are each augmented by the addition of constants, creating two resulting signals which are divided then augmented by the addition of a constant.