Whats the difference between resolution and pixel spacing?
The terms resolution, pixel size and pixel spacing are related terms, but cannot be used interchangeably. Pixel spacing represents how much area each pixel covers, while resolution indicates the smallest object you could pick out in an image. Each pixel represents one solid color, so of course you can’t see anything within it. When you place other pixels around it, though, you might notice a few pixels are rather different in color than surrounding pixels and conclude that you have identified a distinct object. For example, an image that has 12.5 m pixel spacing and about 30 m resolution.
