Patent ID: 7352911

Claim:
A method for processing an image using a bilateral filter, comprising the steps of: generating a modified bilateral filter by reformulating an initial bilateral filter for each pixel location in the image into a sum of the original signal value of a central pixel at said pixel location and a bilateral correction term which is a function of local signal differences between the central pixel and its neighbors; processing each pixel (i) in the image by: buffering a neighborhood of said pixels as determined by the size of the bilateral filter convolution kernel Kj; and calculating a filtered value for said pixel (i) using a bilateral filter including a normalization expression implemented as a Taylor series expansion; replacing the normalization expression with a value of 1; for each possible quantized said signal difference: pre-calculating the product of the photometric weight for each neighboring pixel j and the signal difference Δf j between pixel j and center pixel i, to produce a signal value PSI(Δf j ) representing the influence of neighboring pixel j; storing each said value of PSI in a look-up table; and using a value of PSI in the look-up table corresponding to an instant value of Δƒ j to calculate the contribution of the neighboring pixel j, by multiplying the value for pixel j with a corresponding convolution kernel coefficient K j .