Crosstalk cancellation in 3D displays

• US 9,148,645 B2
• Filed: 05/01/2012
• Issued: 09/29/2015
• Est. Priority Date: 05/14/2011
• Status: Expired due to Fees

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: Doutre, Colin R., Nasiopoulos, Panos
• Primary Examiner(s): Czekaj, Dave
• Assistant Examiner(s): Rahman, Mohammad J
• Application Number:
  US13/461,723
• Publication Number:
  US 20120287250A1
• Time in Patent Office: 1,246 Days
• Field of Search: 348/51
• US Class Current: 1/1
• CPC Class Codes: H04N 13/122 Improving the 3D impression of stereoscopic images by modifying image signal contents, e.g. by filtering or adding monoscopic depth cues H04N13/128 takes precedence
• CPC Class Codes: H04N 13/125 for crosstalk reduction
• CPC Class Codes: H04N 13/324 Colour aspects
• CPC Class Codes: H04N 2213/002 Eyestrain reduction by processing stereoscopic signals or controlling stereoscopic devices

Abstract

Image processing is performed to facilitate subtractive crosstalk cancellation in 3D images. In a global embodiment, pixel values are compressed to provide sufficient foot room for subtractive crosstalk cancellation. For video images the degree of compression may vary from frame to frame. Temporal filtering may be applied to reduce flicker. In a local embodiment luminance is added to and/or compression is performed in local areas to facilitate more complete subtractive crosstalk cancellation. The amount or added luminance or compression may be matched to the requirements of the local areas. Added luminance and/or compression may be made to vary smoothly in time and smoothly in space. Displays and other apparatus may be constructed to perform methods for partial or complete crosstalk cancellation.

Claims

1. A method for preparing 3D images comprising left-eye and right-eye views for display, the method comprising:

based on image data determining amounts to increase pixel values to allow complete subtractive crosstalk cancellation;

determining a maximum of the amounts;

globally increasing the pixel values by one or both of addition and scaling in an amount based on the maximum

wherein the 3D images comprise video frames in a video sequence, the method comprises applying a temporal low pass filter to the maximum or an amount derived from the maximum and the temporal filter comprises a bidirectional filter.

13. A non-transitory medium carrying a set of computer-readable signals comprising instructions which, when executed by a data processor, cause the data processor to execute a method for preparing 3D images according to any one of claims 1 to 12.

2. A method for preparing 3D images comprising left-eye and right-eye views for display, the method comprising:

based on image data determining amounts to increase pixel values to allow complete subtractive crosstalk cancellation;

determining a maximum of the amounts;

globally increasing the pixel values by one or both of addition and scaling in an amount based on the maximum

wherein determining amounts to increase pixel values comprises computing;

R_K(x,y)=max(0,F(I_C,K(x,y))−

I_S,K(x,y))

where R_k is the amount to increase a pixel located at position (x,y), F( ) is a crosstalk function, I_S,K is the value for the color channel K of a pixel in one view of the image, I_C,K is the value for the color channel K of a pixel in another view of the image.

3. A method according to claim 2 wherein F( ) comprises multiplication by a crosstalk factor c.

4. A method for preparing 3D images comprising left-eye and right-eye views for display, the method comprising:

based on image data determining amounts to increase pixel values to allow complete subtractive crosstalk cancellation;

determining a maximum of the amounts;

globally increasing the pixel values by one or both of addition and scaling in an amount based on the maximum

wherein globally increasing the pixel values comprises globally scaling and/or adding to values in a luminance channel in a color model having separate luminance and chrominance channels and the color model comprises a YCbCr color model.

5. A method for preparing 3D video images comprising left-eye and right-eye views for each of a series of frames for display, the method comprising:

identifying local areas in a view where pixel values are too small to allow complete subtractive crosstalk cancellation;

determining intensities for patches of luminance to add to the local areas;

temporally low-pass filtering the intensities; and

generating the patches of luminance according to the temporally filtered intensities;

wherein the patches of luminance ramp up to the temporally filtered intensities in boundary regions surrounding the local areas.

6. A method according to claim 5 comprising, for each of the patches of luminance generating a corresponding patch of luminance for the other view.

7. A method according to claim 6 wherein generating a corresponding patch of luminance comprises locating a center of the patch of luminance, performing block matching to estimate the disparity between the views at a location corresponding to the center of the local area and adding to the other view a copy of the patch of luminance shifted in the x-direction by the estimated disparity.

8. A method according to claim 5 comprising adding a fade out to each patch of luminance in frames subsequent to a last frame for which the patch of luminance is associated.

9. A method according to claim 5 comprising adding a fade in to each patch of luminance in frames prior to a first frame for which the patch of luminance is associated.

10. A method according to claim 7 wherein the block matching is performed with a block size of 16 pixels or more.

11. A method for preparing 3D video images comprising left-eye and right-eye views for each of a series of frames for display, the method comprising:

identifying local areas in a view where pixel values are too small to allow complete subtractive crosstalk cancellation;

determining intensities for patches of luminance to add to the local areas;

linking corresponding local areas across frames of the video images to provide one or more series of linked local areas;

identifying a first linked local area of one of the series of corresponding linked local areas; and

adding fade-in patches of luminance corresponding to the first linked local area to a series of frames preceding the frame corresponding to the first linked local area.

12. A method according to claim 11 comprising identifying a last linked local area in the one of the series of corresponding linked local areas and adding fade-out patches of luminance corresponding to the last linked local area to a series of frames succeeding the frame corresponding to the last linked local area.

14. Apparatus for preparing 3D images comprising left-eye and right-eye views for display, the apparatus comprising:

means for processing image data to determine amounts to increase pixel values to allow complete subtractive crosstalk cancellation;

means for determining a maximum of the amounts;

means for globally increasing the pixel values by one or both of addition and scaling in an amount based on the maximum

wherein the 3D images comprise video frames in a video sequence and the apparatus comprises means for applying a temporal low pass filter to the maximum or an amount derived from the maximum; and

the temporal filter comprises a bidirectional filter.

25. Apparatus according to claim 14 provided in a display, a graphics card, a 3D projector, a video player, a media player, or a 3D digital cinema projector.

15. Apparatus for preparing 3D images comprising left-eye and right-eye views for display, the apparatus comprising:

means for processing image data to determine amounts to increase pixel values to allow complete subtractive crosstalk cancellation;

means for determining a maximum of the amounts;

means for globally increasing the pixel values by one or both of addition and scaling in an amount based on the maximum

wherein the means for processing image data to determine amounts to increase pixel values is configured to compute;

R_K(x,y)=max(0,F(I_C,K(x,y))−

I_S,K(x,y))

where R_k is the amount to increase a pixel located at position (x,y), F( ) is a crosstalk function, I_S,K is the value for the color channel K of a pixel in one view of the image, I_C,K is the value for the color channel K of a pixel in another view of the image.

16. Apparatus according to claim 15 wherein F( ) comprises multiplication by a crosstalk factor c.

17. Apparatus for preparing 3D images comprising left-eye and right-eye views for display, the apparatus comprising:

means for processing image data to determine amounts to increase pixel values to allow complete subtractive crosstalk cancellation;

means for determining a maximum of the amounts;

means for globally increasing the pixel values by one or both of addition and scaling in an amount based on the maximum

wherein the means for globally increasing the pixel values comprises means for globally scaling and/or adding to values in a luminance channel in a color model having separate luminance and chrominance channels; and

the color model comprises a YCbCr color model.

18. Apparatus for preparing 3D video images comprising left-eye and right-eye views for each of a series of frames for display, the apparatus comprising:

means for identifying local areas in a view where pixel values are too small to allow complete subtractive crosstalk cancellation;

means for determining intensities for patches of luminance to add to the local areas;

means for temporally low-pass filtering the intensities; and

means for generating the patches of luminance according to the temporally filtered intensities.

19. Apparatus according to claim 18 wherein the means for generating the patches of luminance is configured to generate for each of the patches of luminance a corresponding patch of luminance for the other view.

20. Apparatus according to claim 18 comprising means for locating a center of the patch of luminance, means for performing block matching to estimate the disparity between the views at a location corresponding to the center of the patch of luminance and means for adding to the other view a copy of the patch of luminance shifted in the x-direction by the estimated disparity.

21. Apparatus according to claim 18 comprising means for adding a fade out to each patch of luminance in frames subsequent to a last frame for which the patch of luminance is associated.

22. Apparatus according to claim 18 comprising means for adding a fade in to each patch of luminance in frames prior to a first frame for which the patch of luminance is associated.

23. Apparatus for preparing 3D video images comprising left-eye and right-eye views for each of a series of frames for display, the apparatus comprising:

means for identifying local areas in a view where pixel values are too small to allow complete subtractive crosstalk cancellation;

means for determining intensities for patches of luminance to add to the local areas;

means for linking corresponding local areas across frames of the video images to provide one or more series of linked local areas;

means for identifying a first linked local area of one of the series of corresponding linked local areas; and

means for adding fade-in patches of luminance corresponding to the first linked local area to a series of frames preceding the frame corresponding to the first linked local area.

24. Apparatus according to claim 23 comprising means for identifying a last linked local area in the one of the series of corresponding linked local areas and adding fade-out patches of luminance corresponding to the last linked local area to a series of frames succeeding the frame corresponding to the last linked local area.

26. A method for preparing 3D images comprising left-eye and right-eye views for display, the method comprising:

based on image data determining amounts to increase pixel values to allow complete subtractive crosstalk cancellation;

determining a maximum of the amounts;

globally increasing the pixel values by one or both of addition and scaling in an amount based on the maximum

wherein globally increasing the pixel values comprises globally scaling and/or adding to values in a luminance channel in a color model having separate luminance and chrominance channels.