How to dither an image

To edit an image with Dithering method you can specify `ThresholdDithering` or `FloydSteinbergDithering` options. The `ThresholdDitherig` is a simple and fast dithering method, and the `FloydSteinbergDithering` is a more complex method that takes into account nearest neighbors' pixels' intensity values. And as a second parameter, you can 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: