Hi,

I'm interested in image scaling algorithms and have implemented the bilinear and bicubic methods. However, I have heard of the lanczos and other more sophisticated methods for even higher quality image scaling and I am very curious how they work.

Could someone here explain the basic idea behind scaling an image using lanczos (both upscaling and downscaling) and why it results in higher quality?

I do have a background in fourier analysis and have done some signal processing stuff in the past, but not with relation to image processing, so don't be afraid to use terms like "frequency response" and such in your answer :)

EDIT: I guess what i really want to know is the concept and theory behind using a convolution filter for interpolation.

(Note: i have already read the wikipedia article on lanczos resampling but it didn't have nearly enough detail for me)

thanks alot!