Resumen en español

This paper describes an algorithm to sharpen a colour digital image based on S-CIE LAB extension. S-CIE LAB involves a series of smoothing spatial filters in the opponent color space to approximate the contrast sensitivity functions of the human vision system. The filters are linear combinations of Gaussian masks. The algorithm combines these spatial filters with the Laplacian operator in each opponent channel to obtain the sharpened image. The resulting image is then subtracted from the original image in each opponent channel and back transformed to the device independent representation space (XYZ) to obtain the final sharpened image. This article describes two examples that use the sharpening algorithm with medical images of the ophthalmic area.