1. A method to zoom a region of interest from a digital image comprises the following steps: (1) define size and location of region of interest as part of source image; (2) calculate scale of conversion in x- and y-direction; (3) calculate number of rows of pixels of destination image according to scale of conversion desired in y-direction; (4) calculate number of pixels contained in a row of pixels of destination image according to scale of conversion desired in x-direction; (5) calculate color values of each pixel along the rows of pixels of the destination image by interpolation from nearest row of pixels of source image; and (6) display zoomed region of interest in destination image.