Gamma Correction
Gamma correction is an optional brightness adjustment applied to images.
Values less than 1 darken the image; values greater than 1 ligthen the image.
A value of exactly 1 leaves the brightness unchanged. For example, here is
an image rendered in four LEGO gray tones (black, white, and two levels of
gray):
![](http://www.lugnet.com/mimg.cgi?160&-&1&1&1&1&.2&1&0000000000d0&/cad/mosaic/catface.jpg) 0.2
| | ![](http://www.lugnet.com/mimg.cgi?160&-&1&1&1&1&.4&1&0000000000d0&/cad/mosaic/catface.jpg) 0.4
| | ![](http://www.lugnet.com/mimg.cgi?160&-&1&1&1&1&.6&1&0000000000d0&/cad/mosaic/catface.jpg) 0.6
|
| ![](http://www.lugnet.com/mimg.cgi?160&-&1&1&1&1&.8&1&0000000000d0&/cad/mosaic/catface.jpg) 0.8
| | ![](http://www.lugnet.com/mimg.cgi?160&-&1&1&1&1&1&1&0000000000d0&/cad/mosaic/catface.jpg) 1.0
| | ![](http://www.lugnet.com/mimg.cgi?160&-&1&1&1&1&1.2&1&0000000000d0&/cad/mosaic/catface.jpg) 1.2
|
| ![](http://www.lugnet.com/mimg.cgi?160&-&1&1&1&1&1.5&1&0000000000d0&/cad/mosaic/catface.jpg) 1.5
| | ![](http://www.lugnet.com/mimg.cgi?160&-&1&1&1&1&2&1&0000000000d0&/cad/mosaic/catface.jpg) 2.0
| | ![](http://www.lugnet.com/mimg.cgi?160&-&1&1&1&1&3&1&0000000000d0&/cad/mosaic/catface.jpg) 3.0
|
Gamma level adjustments can be applied to full-color images as well. For
example, here is an image rendered in five classic LEGO colors (black, white,
red, blue, and yellow):
Note: gamma correction isnt quite the same as a brightness adjustor. With
gamma correction, pure black stays black and pure white stays white. The
curve in between black and white changes shape based on the gamma value.
|