Sub-Pixel Accuracy

Every quantity, piece of information, or feature that can be extracted from an image is limited by the image's pixel quantization. However, by examining a neighborhood of the point to be extracted, it is possible to provide an approximate estimate of the feature's position with sub-pixel precision. These approaches are all based on locally modeling the quantized image function, attempting to reconstruct the information lost through spatial quantization.

Each problem has its own specific technique for extracting this information. Some of them are examined in this section.