Systems and methods for color compensation in multi-view video
View Patent ↗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.
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 slave channel, wherein the global color ratio statistics are based on a ratio of master channel image data to master channel image size and a ratio of slave channel image data to slave channel image size, and wherein the slave channel image size depends on the similarity between a master channel image and a slave channel image;
calculating at least one compensation gain based upon the set of global color ratio statistics; and
applying the at least one compensation gain to the slave channel to obtain a gain-compensated first slave channel.
2. The method of claim 1 further comprising:
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.
3. The method of claim 2 comprising calibrating a golden camera with a standard reference to generate the initial color correction matrix, wherein the golden camera has color ratios that fall toward a statistical mean.
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 2 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 video image processor comprising:
a master channel; and
a slave channel, wherein the video image processor is configured to:
determine a set of global color ratio statistics from the master channel and the slave channel, wherein the global color ratio statistics are based on a ratio of master channel image data to master channel image size and a ratio of slave channel image data to slave channel image size, and wherein the slave channel image size depends on the similarity between a master channel image and a slave channel image;
calculate a compensation gain based upon the set of global color ratio statistics; and
apply the compensation gain to the slave channel.
11. The video image processor of claim 10 further comprising a plurality of slave channels.
12. The video image processor of claim 11 further comprising a plurality of master channels, wherein each master channel is associated with one or more slave channels.
13. The method of claim 2 wherein the initial color correction matrix is a unit matrix.
14. The method of claim 10 , wherein the video image processor is configured to:
generate a master channel color correction matrix;
generate a slave channel color correction matrix; and
apply 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.