CMYK_rj Last Revised: 26 May 2005

RocketJet4 - Tools

CMYK Film Color Correction Filter for VirtualDub.

(Based on RGB Color Equalizer by Tamás B. Bakó).

This filter is designed for correcting the type of colour faults found in photographic film, which is very different to electronic video errors.
Modern color film is typically based on layers of Cyan, Magenta and Yellow. This is the basis of the controls for CMYK_rj.

• 8 sliders are available in total,
  allowing adjustment of magnitude and base level
  of each of the 4 colour layers.

C_=_Cyan _ M_=_Magenta _ Y_=_Yellow _ K_=_Black

* = Amplify Magnitude
+ = Move Base Level

• 2 Presets are available for common color fading.

#R = Too Red_(common with faded print)
#B = Too Blue (from faded yellow negative)

This here is a TEST version:

It is still under development.

Mainly because....

• The filter is very slow.

• Sometimes the sliders are eccentric.

 

DOWNLOADS


* * Remember to do a VIRUS check * *

Download _ CMYK_rj ___Ver 1.0:

• Current BETA Version - 5k Zip file

Last Revision:-__ 25 May 2005 _- Build 5525

- Slight performance improvement.
- Fixed "Overloaded" bug.

 

 

• SOURCE CODE - 21k Zip file - C++
  

Technical notes:

A while back I looked around for a VirtualDub filter that would provide CMYK based colour correction, but found nought. The closest I found was Tamás B. Bakó's RGB Color Equalization filter, which provides for offset correction of color levels.

I have used this as a basis to create a CMYK style correction filter, although I have taken some liberties with color space conversion for the sake of speed. (CMYK operates with color differences, sort of a little like a bizzaro analog of YUV.)

Although the filter could use further development, I have found it so useful already that I decided to go ahead and publish it anyway.

The main limitation at this stage is that not all the amplification sliders can be used at the same time. However, the offset sliders do not have this problem (or at least I haven't seen it yet.)

The filter is slow, and the layout of the controls is still a bit ugly,
but it is quite useable.

At some stage I should also add Gamma controls...one day...