SYSTEMS AND METHODS FOR COLOR COMPENSATION IN MULTI-VIEW VIDEO

• US 20130033585A1
• Filed: 03/06/2012
• Published: 02/07/2013
• Est. Priority Date: 08/04/2011
• Status: Active Grant

• Current Assignee: Semiconductor Components Industries LLC (ON Semiconductor Corporation)
• Original Assignee: Aptina Imaging Corporation (ON Semiconductor Corporation)
• Inventors: Sun, Qun, LI, DONG
• Granted Patent: US 9,264,689 B2
• Time in Patent Office: Days
• US Class Current: 348/51
• 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 13/15 for colour aspects 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 13/243 using three or more 2D image sensors
• CPC Class Codes: H04N 13/246 Calibration of cameras

Abstract

An apparatus and a method for color compensation in multi-view video is provided. Video sequences corresponding to a common scene of interest are captured and processed using the master and slave channels respectively. A compensation gain is calculated based on a set of global color ratio statistics obtained from the master and slave channels. The compensation gain is applied to the slave channel. An initial master color correction matrix is combined with a master color matching matrix to obtain a final master color correction matrix. The initial slave color correction matrix is combined with a slave color matching matrix to obtain a final slave color correction matrix. The master and gain-compensated slave channels are color-compensated by applying the final master and final slave color correction matrices to the master and gain-compensated slave channels, respectively.

Claims

1. A method for color compensation in multi-view video comprising:

sensing a first video sequence in a master channel;

sensing a second video sequence in a slave channel;

wherein the first and second video sequences are acquired from a common scene of interest;

generating a set of global color ratio statistics from the master channel and the first slave channel;

calculating at least one compensation gain based upon the set of global color ratio statistics;

applying the at least one compensation gain to the slave channel to obtain a gain-compensated first slave channel;

combining an initial color correction matrix with a first color matching matrix to obtain a final master color correction matrix;

combining an initial color correction matrix with a second color matching matrix to obtain a final slave color correction matrix; and

color-compensating the master channel and the gain-compensated slave channel by applying the final master and final slave color correction matrices to the master channel and the gain-compensated slave channel, respectively.

2. The method of claim 1 wherein the initial color correction matrix is a unit matrix.

3. The method of claim 1 comprising calibrating a golden camera with a standard reference to generate the initial color correction matrix.

4. The method of claim 3 comprising calibrating a further camera with the golden camera to generate the color matching matrix.

5. The method of claim 3 wherein the golden camera is the master channel.

6. The method of claim 1 wherein the first and second color matching matrices are unit matrices.

7. The method of claim 1 wherein the set of global color ratio statistics is generated from a first set of Bayer values obtained from the master channel and a second set of Bayer values obtained from the slave channel.

8. The method of claim 1 comprising a plurality of slave channels.

9. The method of claim 1 comprising a plurality of master channels, wherein each of the plurality of master channels is associated with one or more slave channels.

10. A method for color compensation of a first video sequence in a master channel and a second video sequence in a slave channel, wherein the first and second video sequences are acquired from a common scene of interest, the method comprising:

generating a set of global color ratio statistics from the master channel and the slave channel;

generating a compensation gain based upon the set of global color ratio statistics;

applying the compensation gain to the slave channel to obtain a gain-compensated slave channel;

combining an initial color correction matrix with a first color matching matrix to obtain a final master color correction matrix;

combining an initial color correction matrix with a second color matching matrix to obtain a final slave color correction matrix; and

color-compensating the master channel and the gain-compensated slave channel by applying the final slave and final master color correction matrices to the master channel and the gain-compensated slave channel, respectively.

11. The method of claim 10 wherein the initial color correction matrix is a unit matrix.

12. The method of claim 10 comprising calibrating a golden camera with a standard reference to generate the initial color correction matrix.

13. The method of claim 12 comprising calibrating a second camera existing in sequence with the golden camera to generate the color matching matrix.

14. The method of claim 10 wherein the color matching matrix is a unit matrix.

15. A video image processor comprising:

a master channel;

a slave channel;

a global ratio statistics calculator for determining a set of global color ratio statistics from the master channel and the slave channel;

a gain calculator for calculating a compensation gain based upon the set of global color ratio statistics;

a gain compensator for applying the compensation gain to the slave channel;

a first color correction matrix generator for generating a master channel color correction matrix;

a second color correction matrix generator for generating a slave channel color correction matrix; and

a video image color compensator for applying the master channel and the slave channel color correction matrices to the master channel and slave channel respectively to generate a color compensated video image.

16. The video image processor of claim 15 further comprising a plurality of slave channels.

17. The video image processor of claim 16 further comprising a plurality of master channels, wherein each master channel is associated with one or more slave channels.