Colour image thresholding at pixel rate using rational arithmetic hardware

Thresholding of images is a common precursor to many object recognition or image analysis methods. Colours images contain more information than monochrome images of the same spatial resolution and in many applications of colour image processing there will be a need for thresholding. The paper presents a hardware implementation and development of a technique published by Pritchard et al. (1994). A brief review is given of the rational arithmetic representation; the authors then discuss the definition of colour purity, present a description of the thresholding algorithm as implemented in hardware and finally, give a block-level description of the hardware implementation and some results obtained