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// Graphics Code

Real-time Image Curves (using cubic splines) in VB6

December 24, 2008

By request, here is the first of its kind in VB: a fast, accurate, real-time image curves dialog. (This should be familiar to any PhotoShop users out there…)

Curves is similar in theory to both “Image Levels” and standard gamma correction, but it provides a much more powerful interface for adjusting the luminance of an image. This project provides results very similar to Photoshop’s, and it allows the creation of more spline knots (32 instead of 16). The cubic spline code on which I based my code was taken from Jason Bullen’s excellent “Simple Cubic Spline Curve Plot” (available at Planet Source Code).

The code is well-commented and very fast – please post comments, requests for future Photoshop-related code, and many heaps of praise (as this was a complicated routine to reverse-engineer…!).