1. A method for aligning a tape cartridge accessor with cartridges in cells of a tape cartridge magazine, comprising: applying IR illumination to an object expected to include a desired physical feature; receiving specular reflections from the illuminated object to create an image of the object; applying dynamic image thresholding to the image to select an optimum gray scale level of the image expected to include the desired physical feature; and using bounding boxes to identify the location of the desired physical feature in the thresholded image.