Patent ID: 7039236

Claim:
An image processor for providing, from a surface image of an object having a pattern, a processed image having a distinct contrast between said pattern and a background, said image processor comprising: a first smoothing filter for generating a first smoothed image by determining, with respect to each of pixels of the surface image, a mean concentration value for said pixel and neighbor pixels in a first region defined around said pixel; a second smoothing filter for generating a second smoothed image by determining, with respect to each of pixels of the surface image, a mean concentration value for said pixel and neighbor pixels in a second region that is defined around said pixel so as to be greater than said first region; a weighting means for multiplying each of pixel values of said first smoothed image by a weight coefficient of 1 or more to determine a weighted pixel value; a differential image generator for subtracting each of weighted pixel values provided by said weighting means from a pixel value of a corresponding pixel of unweighted said second smoothed image to generate a differential image; and an image extracting means for extracting only pixel values having the positive sign from said differential image to obtain said processed image.