In this paper, we propose an algorithm for the measure of local and global contrast in digital images. It applies locally, at various sub-sampled levels, a simplified computation of local contrast based on DOG and finally it recombines all the values to obtain a global measure. The proposed method comes from the modification of a previous algorithm with a different local measure of contrast and with a parameterized way to recombine color channels. As new approach we propose the idea of recombining the channels following measures taken from the image itself. Preliminary tests and results are presented and discussed.