Method and apparatus for compensating for color variation in a video system
First Claim
1. A method of tracking a moving prop having one or more color regions, each of said color regions being subject to deviation from a nominal value, comprising the steps of:
- observing a color ratio of one of said color regions of said moving prop;
for each of said color regions, updating an expected color ratio based on said observed color ratio; and
employing said expected color ratio for detecting said color region of said moving prop.
3 Assignments
0 Petitions
Accused Products
Abstract
Compensating for color variations affecting color detection by a video system. In one aspect, compensation for highlights of a prop having multiple color regions is provided. The prop is preferably designed so that every color region of the prop is affected by highlights at the same rate. The color mix ratio for a color region of the prop representing the deviation of the color region from a nominal color value is computed, and an expected color for each color region of the prop is then computed based on the color mix ratio. In another aspect, compensation for variations in a light source illuminating the environment detected by the video system are provided in combination with highlight compensation. A white color balance ratio for a frame of video data is estimated, the color ratios of background white pixels are detected and these ratios are then used to continually update the estimate of the white color balance ratios.
-
Citations
15 Claims
-
1. A method of tracking a moving prop having one or more color regions, each of said color regions being subject to deviation from a nominal value, comprising the steps of:
-
observing a color ratio of one of said color regions of said moving prop; for each of said color regions, updating an expected color ratio based on said observed color ratio; and employing said expected color ratio for detecting said color region of said moving prop.
-
-
2. A method of tracking a prop having one or more color regions, each of said color regions being subject to deviation from a nominal value, comprising the steps of:
-
observing a color ratio of one of said color regions of said prop; for each of said color regions, updating an expected color ratio based on said observed color ratio; employing said expected color ratio for detecting said color region of said prop; and detecting a loss of tracking of said prop. - View Dependent Claims (3)
-
-
4. A method of tracking a prop having one or more color regions, comprising the steps of:
-
detecting a color ratio for a selected color region of said prop; computing for said color region a mix ratio, said mix ratio representing a proportional deviation from a nominal color value of said color region; computing for each of said color regions of said prop a desired color, said desired color being the sum of said nominal color and the product of said mix ratio and a difference between said nominal color and a maximum whiteness of said color region; and employing said desired color of each of said color regions in tracking said color regions.
-
-
5. The method of step 4 and further including clipping said mix ratio to a predetermined range.
-
6. The method of step 5 and further including the step of detecting loss of tracking of said prop.
-
7. The method of step 6 and further including the step of substituting for said mix ratio a predetermined mix ratio when a loss of tracking of said prop is detected.
-
8. A color compensation system, comprising:
-
a prop having a plurality of color regions, each of said color regions being subject to whiting out at an equal rate; a detector for detecting a color ratio of a measured color region, said measured color region being one of said color regions; a processor for; (i) computing for said color region a deviation from a nominal value of said color region; and (ii) computing for each of said color regions of said prop an expected color ratio, said ratio representing said nominal color of said color region, adjusted by said deviation from said nominal value of said measured color region. - View Dependent Claims (15)
-
-
9. A method of white balance compensation for a succession of frames of video data, comprising the steps of:
-
for each frame, estimating a white color balance ratio; for each frame, also estimating color ratios for background white pixels; employing said estimates of said color ratios to compute a new estimate of said white color balance ratio for each subsequent frame of video data; and also employing said estimates of said color ratios to compensate for variations in a light source affecting subsequent frames of video data. - View Dependent Claims (10, 11, 12, 13, 14)
-
Specification