Bicubic Interpolation Algorithm of imrotate

Hello,

does anyone know the exact code for the bicubic interpolation algorithm used in imrotate()? I am currently rewriting a matlab script containing this function into a cuda mex file. My current implementation produces small differences between the matlab rotated images and the images I rotate. Is it the algorithm mentioned in this paper?

Thanks for your help

Answer 1

[Kshitij Chhabra]

Hi Leoluca,

From my understanding of the question, you are trying to find the exact code which is used to perform the bicubic interpolation in “imrotate” function of MATLAB. “imrotate” uses the same algorithm as followed by the paper in the MATLAB Answer link that you have attached:

R. Keys, "Cubic convolution interpolation for digital image processing," in IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. 29, no. 6, pp. 1153-1160, December 1981, doi: 10.1109/TASSP.1981.1163711.

Also, as a sidenote, “imrotate” already supports GPU Code generation and you can directly use that for your application.

Hope this helps!