color mapping graphs

[mikegentile]

i was wondering if there were any graphs or images of gradients out there for the different color mapping types and values. to help visually explain what each is doing.

thanks
mike

[RErender]

The Reinhard color mapping does not apply any gamma transformation on the result. Here are some curve graphs demonstrating how different color mapping modes work. The x axis is the input (original) image color, and the y axis is the output (color-mapped) color.



Useful observations:

• In the last image, although this is not clear from the limited graph window, neither the Exponential, nor the Reinhard with Burn 0.0 curve ever go above the 1.0 (white) value (e.g. no burnt-out areas). However, the Exponential graph goes very close to white very quickly, while the Reinhard curve is more gradual.
• Near the dark colors, the slope for both Exponential and Reinhard modes is similar to the slope of the linear mapping, which means that those modes preserve darker colors near their original value.
• When the Burn value is 0.5, the Reinhard curve intersects the y=1 line (the white color) when x=2 (the original color has an intensity of 2); when the Burn value is 0.2, the curve intersects the white line for x=5; the same relationship is true for any other color and allows you to choose presicely the values of the colors that you want to be mapped to white.

Here are larger versions of the images:

http://www.spot3d.com/vray/images/re...ard_burn10.png
http://www.spot3d.com/vray/images/re...ard_burn05.png
http://www.spot3d.com/vray/images/re...ard_burn02.png
http://www.spot3d.com/vray/images/re...ard_burn00.png
http://www.spot3d.com/vray/images/re...xponential.png

Best regards,
Vlado

Here is the entire thread http://www.chaosgroup.com/forums/vbu...ad.php?t=34747

Doesn't cover linear but that is pretty straight (no pun intended ) forward

[RErender]

Four image per post limit...

[mikegentile]

thanks!
i'll render graidents to match those graphs.
and make graphs to match these gradients.

-mg