I know its an old technique but can someone tell me in which areas the image dithering technique is used and why?
Please edit the question to limit it to a specific problem with enough detail to identify an adequate answer. Avoid asking multiple distinct questions at once. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.
In image compression, when the number of bits per pixel are reduced, you might see an artifact called contouring. Dithering is used to reduce this artifact.
For more information, please see