Gradation Curves Change Log:

Version 1.45 (21.03.2008)
Major enhancements of the curve editor:
• Enhanced the freehand drawing mode when moving the cursor outside of the curve box
• Added the possibility to edit the curve by using coordinate points:
  • Added a point-line-point editor mode
  • Added a gamma editor mode + display of the gamma value
  • Added a spline editor mode
• Changed the fine tune interface (and dropped the slider)
Other enhancements:
• Added import and export of .acv files
• The .crv and .map import now also reads coordinates and the drawing mode
• Faster filter preview (filter preview window)
• Minimal speed improvement of the RGB modes

Version 1.36 (10.02.2008)
• 1.36 fixes a bug in 1.35 with Lab space when using jobs or processing settings stored in vcf files
• Added support for the Lab color space!
• Speed improvements for CMYK and HSV color spaces, quality improvement for HSV
• Some code cleanup

Version 1.25 (28.12.2007)
• Added support for the following color spaces: YUV, CMYK, HSV
• Added different formats to the curve import function: Comma Separated Values, Tone Curve File, Tone Map File, SmartCurve HSV
• Added the Comma Separated Values format to the curve export function
• Higher quality color space conversion (YUV, HSV)

Version 1.21 (18.01.2005)
• Added direct mouse filter edit support

Version 1.11 (21.01.2004)
• An import/export function has been integrated to import/export .amp files
• A small bug in the weighted mode is now fixed

Version 1.00 (08.01.2004)
• First release

How I started with the Gradation Curves filter:

Back in 2003 I was capturing a lot of analogue TV (anime) and had to do denoising before saving to a highly compressed avi file. Comparing before and after denosing, dark tones got to dark and I wanted to brighten dark areas up without doing a general increase in brightness. I knew that this could be done with a (gradation) curves filter, a filter that is widely used in digital still image processing. As such a filter did not exist for VirtualDub I decided to start coding my own. Downloaded the filter SDK, searched some old (DOS) Borland Turbo C books from back school and started off. So I wanted to increase the brightness of dark tones subtle and this was one of my first results:

With Java enabled you can visualize the processed video image by moving over with the mouse.

The above filter setting was used. With the mouse over the image you can see dark tones lighted up subtle.

This is the corresponding .amp file: lighterdarktones.amp