Colour mapping in post

Hi all,

quick question…

If I render out a 32bit exr in Linear is there any application that can apply colour mapping controls like Exponential or Reinhard?.

I realize photoshop is one option (playing with levels) but Im wondering if there are other applications I might have missed that maybe wpuld do a better job?

cheers!

try to create a similar curve in your post production aplication

Hi there,

I believe there are a number of tone mapping programs and plug-ins for Photoshop available.. Photomatix being one of the most popular..

Cheers

There are a number of tools out there that can perform tonemapping (including local tonemapping). Keep in mind that you should add the colourmapping settings anyways in vray and check “dont affect colours” as otherwise sampling is performed in linear space wich may lead to bad sampling (=noise) in dark areas that are lifted in post.

Regards,
Thorsten

I’ve been looking into this as I rarely have time to test several Reinhard burn values before I render the final. I too would love to do it in post. I found this for AE:

http://www.minning.de/software/atlas

It is free and open source, but that usually means it won’t be developed much further. Anyone else have any tone-mapping techniques (preferably AE) that can do a Reinhard effect in post?

Ryan

I thought “dont affect colours” means it won’t even look at your colour mapping settings. Are you saying it will do the sampling WITHOUT colour mapping but still final render WITH colour mapping?

No, it’s the other way round - it will do the sampling with the color mapping, but it will not be included in the final rendering.

Best regards,
Vlado

so then if I also use sub pixel mapping and clamp output, the sampling will include these two, but the final render will ignore it?

Bringing this back from the dead. Could anybody explain how to achieve this in AE or Photoshop please without plugins. Is it possible without plugins? If I look at my “curves” of my 32 bit image (or any image for that matter) in photoshop, it starts of with just a straight line going from bottom left to upper right. (even if it is gamma 2.2). So I have no idea how am I supose to display the curves as you show here in the attached sample

One amazing thing would be to get same tone mapping as vray one in Toxik/Composite. So we could adjust rendering with vray tone mapping, then switch back to linear/gamma2.2/don’t affect colors, and do same tone mapping in Toxik as a start point. With maxscript we could even write a precomp for toxik with tone mapping inside. Is there a way to get different vray tone mapping algorhytmes so we could try to write a python script or a new VrayToneMap node in Toxik ? Workflow wise, this would be just amazing !

Colormapping is not the same as tonemapping. Tonemapping usually refers to compressing dynamic range locally. VRay’s color mapping is essentially a simple curve correction. With the curve beeing dependent on the mode and settings. Linear gamma can be reproduced with a simple gamma correction. Others need more elaborate set ups, but should be possible without a specific node.

Regards,
Thorsten

Yes of course, was talking about vray color mapping rollout. Would be nice to have same parameters inside Toxik as a starting point working on exr linear.

Oh my, i got really concused now…
So if i use lets say

Reinhard at 0.35 and gamma 2.2
Dot affect colors checked and subpixel/clamp off

What does it actually mean? :slight_smile:

It means that you will render in linear gamma 1, display depending on your max preferences (gamma 1 or 2.2), and your sampling (aa, dmc) will be done on a gamma 2.2 flattened by reinhard curve image.

Thanks for the explanation!

Hey there,

Is there a way of having this same (or more detailed) curve for the HSV Exponential?
I don’t know the mathematical algorithm that sits behind, but it would be great to be able to create that color mapping in post…

Whatever I try, going from linear and comping, I’m always ending with a washed out image like the Reinhard curve (render or post)
But I would like to keep the vivid of the render, HSV Expo does that, and it would be great what exactly it does to be able to reproduce this in comp. (we need to go out in linear for the comping)

Thanks

Stan

Which program are you using for compositing? The HSV exponential mapping cannot be represented by RGB curves only, the maths is more complicated…

Best regards,
Vlado

Afx, I know it’s not as powerful as nuke or other real comp progs, but I was hoping to be able to get away with some curves. Because AFX curves are crap, i’m using FL Curves from Frischluft.

If it’s not powerful enough, is there any other way of doing it in afx?

I’m already quite close to the Reinhard with this, but I’m playing only with RGB, maybe the other options could help for this matter?

Maybe a script expression involving those channels ?

Thanks Vlado!

Stan

Hm, adjusting the brightness curve in the same shape should give you what you want.

Best regards,
Vlado

Nice! It seems to be a lot close indeed, and it preserve the color!
Is there any way of expression scripting this curve, either the reinhard or the HSV Expo?

Thanks again,

Stan