If we have a sprite image, like the StackOverflow sprite, and CSS properties like:
background-position: 0px 0px;
width: 250px;
height: 61px;
We can use the Chunky PNG library to crop out a specific part of the sprite. However, some websites use negative background positions, such as ccs. Their sprite image is located at and the logo has the following CSS attributes:
background-position: -300px -100px;
width: 166px;
height: 80x;
When trying to crop using coordinates with methods that only accept positive values, how do we translate these negative values into something that the method can work with?