WhiteBalance
Module used for white balancing adaptation of a color image. Given a reference image area and a target color, for example a white part of the input image and the color coordinates for white, applies von Kries adaptation to the image. This will transform the reference area the target color and simultaneously change the color coordinates for all other pixels in the image. The image region for the reference color is given by x0, y0, x1, and y1 and the color of the reference region is given by red_target, green_target and blue_target. In addition, the average color of an arbitrary region can be written to the output, This region is set by the log-parameters.
Example XML definition
A simple example
<module
class = "WhiteBalance"
name = "WhiteBalance"
/>
Parameters
| Name | Description | Type | Default |
|---|---|---|---|
| class | The class name for the module; must be "WhiteBalance". | string | |
| name | The name of this instance of the module. | string | |
| red_target | Coordinate for the red channel of the target color | float | 255 |
| green_target | Coordinate for the green channel of the target color | float | 255 |
| blue_target | Coordinate for the blue channel of the target color | float | 255 |
| x0 | Left coordinate for the reference region (inclusive) | int | 10 |
| x1 | Top coordinate for the reference region (exclusive) | int | 10 |
| y0 | Right coordinate for the reference region (inclusive) | int | 20 |
| y1 | Bottom coordinate for the reference region (exclusive) | int | 20 |
| log_x0 | Left coordinate for the logged region (inclusive) | int | 0 |
| log_x1 | Top coordinate for the logged region (exclusive) | int | 0 |
| log_y0 | Right coordinate for the logged region (inclusive) | int | 0 |
| log_y1 | Bottom coordinate for the logged region (exclusive) | int | 0 |
Module Connections
Inputs
| Name | Description |
|---|---|
| INPUT0 | The first input |
| INPUT1 | The second input |
| INPUT2 | The third input |
Outputs
| Name | Description |
|---|---|
| OUTPUT0 | The output |
| OUTPUT1 | The output |
| OUTPUT2 | The output |
Limitations
The reference region can only be set in the XML-file and can not change during execution. This should be changed in the future with either an adaptive white calcuation or an attention based method.
References
von Kries, J. (1902) Chromatic adaptation. In MacAdam, D. L. (Ed.) Sources of color vision, 109-119, Cambridge, MA: MIT Press.
Balkenius, C., Johansson, A. J, and Balkenius, A. (2003). Color constancy in visual scene perception. Lund University Cognitive Studies, 98.
Author
Christian Balkenius
christian.balkenius@lucs.lu.se
Lund University Cognitive Science
Files
WhiteBalance.h
WhiteBalance.cc
WhiteBalance.ikc