How do width, height and resolution matter, and what's the standard or how to calculate the right resolution for current width and height in order to achieve a well refined image or retina image, or an image that is not pixelated?
I want to make some images that are very good quality like an android icon, a game character, and a wallpaper. But I don't know if there are any standards on deciding the size. References and cheat sheets would be a great help. Thanks in advance :)