Bucubic Interpolation Help !!!!

I’ve been trying to implement bicubic interpolation for enlarging images, and I found an explanation for bicubic interpolation here http://astronomy.swin.edu.au/~pbourke/colour/bicubic/

and I’ve implemented it, but it does not seem to be working. I tried it on a single 2x2 image, with the 4 pixel values of Red,Blue,Yellow, and Green, and after enlarging the 2x2 image to an 8x8 image, it simply had a faded dark red in the upper left and then diagnolly down to the right was a darker red, then every other pixel was black.

Can anybody help me with my code?

http://cs.selu.edu/~soconnell/code.txt

Try this http://www.codeproject.com/KB/openGL/GLSLBiCubicInterpolation.aspx

Following Bi-Cubic interpolation are implemented in this.
Triangular, Bell, BSpline, CatMull Rom.

Thanks GL Starter, for this wonderful link :slight_smile:

I have until now only using standards GL_[NEAREST|LINEAR][MIPMAP[NEAREST|LINEAR]] minify/magnify texture filters or “basics” shaders for to handle interlaced video frames and results from various bi-cubic interpolations explained in this link (like B-Spline or Catmull-Rom interpolations for example) seem really impressionnants …