1. A crop quality sensor for a harvesting machine, comprising: an illumination source; an imaging device; a processor; software executing on the processor; wherein the imaging device is mounted in the clean grain elevator of a harvesting machine such that it can capture images of a crop sample moving through the clean grain elevator; wherein the illumination source is mounted near the imaging device and shone onto the crop sample; wherein the crop sample is such that individual kernels of the crop have a shiny outer casing and a dull inner surface when broken open; wherein an image is taken with the imaging device of the illuminated crop sample; wherein the software is executing on the processor; wherein the software is used to analyze the image to identify the outlines of individual kernels and to identify which of those outlines contain a specular highlight; and wherein the presence of a specular highlight within an outline is indicative that the kernel is whole and unbroken and the absence of such a specular highlight is indicative of a broken kernel.