Abstract
We propose a O(1) algorithm for bilateral filter using center-weighted spatial filter. We show that a bilateral filter can be converted into weighted histogram operation. Applying line buffers of column histograms, we can reduce the number of calculation needed to construct recursive center-weighted local histogram. We used a 2-GHz CPU with our method and confirmed that processing time is independent of filter radius. Also, we achieved high PSNR over 40dB.
