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The number of possible picture colors is limited to about 200. This is sufficient for drawing pictures, but this need not be sufficient for photographs or some other pictures utilizing more colors. Therefore a technique called dithering is used when loading multicolored pictures. When using the dithering, alternating multicolored dots instead of a compact colored area are utilized, so that a impression of the required color shade may be reached if viewed in a normal way.
The difference is visible in the following pictures. Without using the dithering the original colors are substituted by the nearest color of colors available. This results in origination of colored areas having sharp transitions, as can be seen in the first picture. In the second picture the situation is illustrated when the dithering is used. If viewed closely, alternate multicolored dots are apparent. If viewed in a normal way the individual dots are not distinguishable, thus giving rise to the perception of real color shades.
In spite of that there are cases in which the dithering may cause troubles. This is above all when loading pictures that are intended for drawing. If the dithering were used in this case, then the colored areas would be filled with a grid of multicolored dots. Thus the function of filling the area with paint would be inhibited. Therefore it is possible to switch the use of the dithering off in the menu.
Without dithering:
Image bm13.GIF
With dithering:
Image bm14.GIF

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