Using nodes to color grade?

Is it at all possible to use Blender’s nodes to do color grading techniques? (Such as those seen in Red Giant’s Magic Bullet plug-in for After Effects) Now I’m not talking major film quality, but just enough to make a normal scene look better.

What do you mean?

Define “color grade”

If you mean changing the color or altering color, there are colorband and curve nodes you can use, you can even seperate the RGBA values using the right nodes.

In simple terms, it’s basically just the enhancement of the color of an image (usually a video). Here’s the more in depth definition.

Here’s an example of before and after. It’s not exactly the best, but it was the only one I could find. Anyway, here it is: http://www.youtube.com/watch?v=ycyj2qDi3E4

And here’s a great example done with After Effects (and a 35mm adapter): http://www.youtube.com/watch?v=PdO4nCpR6wk&feature=related

Now here’s an example with an image done using photoshop: http://ebin.wordpress.com/2007/03/21/how-to-turn-your-photo-into-movie-like-effect-using-photoshop/

I’m not sure if it’s true, but I’ve heard that this effect is possible using Blender’s nodes. . Does anyone have any ideas???

You can simply use color curves and defocus for a similar effect to the Photoshop example, use the ‘Color’ ‘R’ ‘G’ and ‘B’ channels for curve tweaking for maximum control.

Is it really that simple??

Defocus will get you your depth of field after you set the focus in the camera settings, curves allow a great range of color effects for the image, some things are more simple then you expect them to be.

Yes, except from further reading of that wiki resource, it seems you also might employ different mix settings like add, multiply, etc. as well as use masking techniques to isolate a specific area (similar to Papa Smurf’s vimeo tuts) or utilize any of the Matte nodes or Convertor nodes to affect the video colors.

Yes, it can be done.

You can also use the different Separater nodes in Convertor submenu to separate the different channels of your tv/broadcast/film signal. Them use the color curve on each one to change them separatly and after wards use the combine node to combine the back to one signal.

Ok, that’s great! Thanks for the help.

It’s been a while since I’ve been here, and my interests lately have turned to using Blender as my main HDV editor (is there anything this program can’t do?) :slight_smile:

So, I thought I would post this here for posterity. I am planning at some point on adding this info to the wiki, or the noob to pro book:

I have been looking at color grading seriously in the last few days, and have had a great time playing with nodes to do it. One of the things that caught my eye and prompted a “what if” was doing “Bleach Bypass”: http://en.wikipedia.org/wiki/Bleach_bypass.

Turns out, it’d dead simple to get the effect quickly:
Image #1 below is the original image
Image #2 is graded using Bleach Bypass Pro
Image #3 is graded using my node setup (in the .blend).

Images compared from: http://www.redpawmedia.com/bbpro.html

pretty darn close, all things considered. Especially for only like 30 minutes of playing with it!

I am pushing hard on attempting all sorts of other interesting things, and will post more soon!

Attachments

bleach_bypass_packed.blend (273 KB)


Nice work and thank you for sharing your set up!!

Bleach bypass, or Color Chrome effect can also be achieved like this:

http://www.loadusfx.net/blender/colorchrome.jpg

The gamma node adjusts the exposure, the overlay mix adjusts the overall effect. If Blender had SoftLight blending mode, the result would be a bit more smoother, especially on the colors.

I also wrote a .fx shader for the GPU filter for VirtualDub to achieve the same effect to video:

http://www.loadusfx.net/virtualdub/filmfxguide.htm