A Color Separation Algorithm with Multi-Levels Grayscale for Glass Printing

This paper proposes a color separation algorithm with multi-levels grayscale for glass printing. Different from the existing algorithms without grayscale for glass printing, we separate the original image into several color separation layers with given grayscale levels, which can be easily applied to n grayscale levels' case. The number of color separation layers for one type of ink is considered before color separation, and grayscale levels of each pixel are varied by value of corresponding layers. After handling the transparency channel, original image is separated through dithering and the related color separation layers are written based on the grayscale intervals. Moreover, we put forward three methods of dividing grayscale intervals by using RGB values or grayscale values. The experiments show that original image can be appropriately separated into multi-levels grayscale and vividly expressed with a small average value.