Graphest DepthDither is a free filter plug-in for Photoshop, it mainly concerns on generating color dither in Photoshop. When you wants to use the image on LCD screen, such as mobile phone, the color depth is not 24 bit, and mostly it's 16 bit. If the image fills with gradient colors, the screen will display color steps, not continuous color. If you use the DepthDither to process the image, the result on PC and on mobile phone will be the same. DepthDither uses 3 ways to make the image seems to be continuous when the color is below 24 bit. It's just like Photoshop, provides diffusion, pattern and noise as the dither modes. You can choose the destination color depth, such as 2 bit, 4 bit, 12 bit, 15 bit, 16 bit, 18 bit, this is the main difference from Photoshop, the latter only provides less than 256 colors mode.