How to dither an image

For editing an image with Dithering method you can specify `ThresholdDithering` or `FloydSteinbergDithering` options. The `ThresholdDitherig` is a more simple and fast dithering method, but the `FloydSteinbergDithering` is a more complex method that calculates nearest neighbors' pixels' intensity values for more smooth results. You can additionally indicate the color palette in bits for use for dithering. More bits mean a higher quality of the resulting image, but at the same time a larger image size: