![]() ![]() Filter Lite is an algorithm by Sierra that is much simpler and faster than Floyd–Steinberg, while still yielding similar (according to Sierra, better) results.Sierra dithering is based on Jarvis dithering, but it's faster while giving similar results.Stucki dithering is based on the above, but is slightly faster.It is slower than Floyd–Steinberg dithering because it distributes errors among 12 nearby pixels instead of 4 nearby pixels for Floyd–Steinberg. The dithering is coarser, but has fewer visual artifacts. Jarvis, Judice, and Ninke dithering diffuses the error also to pixels one step further away.This results in very fine-grained dithering. Floyd–Steinberg dithering only diffuses the error to neighboring pixels.One of the strengths of this algorithm is that it minimizes visual artifacts through an error-diffusion process error-diffusion algorithms typically produce images that more closely represent the original than simpler dithering algorithms.Įrror-diffusion dithering is a feedback process that diffuses the quantization error to neighboring pixels. One of the earliest, and still one of the most popular, is the Floyd–Steinberg dithering algorithm, developed in 1975. There are several algorithms designed to perform dithering. Dithering takes advantage of the human eye's tendency to "mix" two colors in close proximity to one another.įor Eink panel, since it is grayscale image only, we can use the dithering algorism to reduce the grayscale level even to black/white only but still get better visual results. Without dithering, the colors in the original image might simply be "rounded off" to the closest available color, resulting in a new image that is a poor representation of the original. The 256 available colors would be used to generate a dithered approximation of the original image. For example, dithering might be used in order to display a photographic image containing millions of colors on video hardware that is only capable of showing 256 colors at a time. One common application of dithering is to more accurately display graphics containing a greater range of colors than the hardware is capable of showing. Note that even though the same palette is used, the application of dithering gives a better representation of the originalĭisplay hardware, including early computer video adapters and many modern LCDs used in mobile phonesand inexpensive digital cameras, show a much smaller color range than more advanced displays. Original image using the web-safe color palette with Floyd–Steinberg dithering. Note the large flat areas and loss of detail.įigure 3. Original image using the web-safe color palette with no dithering applied. Original photo note the smoothness in the detailįigure 2. ![]() Dithered images, particularly those with relatively few colors, can often be distinguished by a characteristic graininess, or speckled appearance.įigure 1. ![]() The human eye perceives the diffusion as a mixture of the colors within it (see color vision). In a dithered image, colors not available in the palette are approximated by a diffusion of colored pixels from within the available palette. Dithering Implementation for Eink D isplay Panelĭithering is a technique used in computer graphics to create the illusion of color depth in images with a limited color palette ( color quantization). ![]()
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