Auto color/contrast/levels correction after rendering

[Metin_7]

Hi,

Well, the subject already says it. In most of the cases, the "Auto Color", "Auto Contrast" and "Auto Levels" operations in Photoshop give my image a much better overall contrast and color levels. I guess that's because GI tends to wash out colors and contrast a little. It would great if you could add an option to perform such an auto color/contrast/levels operation over the VRay-rendered image. Especially when it comes to animation it's quite a hassle to perform the operation(s) on all the individual frames in Photoshop afterwards. And it can do quite a lot to the look of a rendered image.

Cheers,

M7

[plastic_]

why hassle? you can record an action and apply it to a folder with automate -> batch processing.

btw..i dont really like what auto color does to rendered images. and i imagine it would cause flickering with animations.
i think it's better to seperate post-processing from the renderer. that said, render elements support would be really important.

[rodigus]

This is completely correct, since PS's auto-levels redistributes the mid-levels from the assumption that the lightest-darkest pixels from the image correspond to white and black. Since each frame has different histograms (different max-min brightness values), you will get different distributions per frame and therefore some flickering will occur.

Generally speaking, auto-level works based on the lightness values for each single image. For an animation, this means different modifications for each frame.

The PS solution: batch processing. This way you can be sure you will have the same distribution for the whole animation. Check out the batch dialog box, it's self-explanatory.

/Diego

[Metin_7]

Well, the animation application of the operation was just an additional hunch, but some built-in post processing would eliminate the need for Photoshop, because for a single rendered image such an operation can perform wonders for the power of the color range.

Cheers,

M7

[egz]

I believe we will get all this when the VRay VFB makes it back into VRay. The few builds that had the VFB beta enabled showed a lot of promise (curve control, histograms etc.).

[Metin_7]

Hi Egz,

You're right. As the VRay VFB already offers image processing operations, an auto correction would be a nice addition i.m.h.o.. I'm sure my old friend Vlado will insert that just for me, won't you Vlado?

Cheerio,

M7