Sub-Pixel Accuracy

Every quantity, piece of information, characteristic that can be extracted from an image is limited by the pixel quantization of the image itself.

However, by examining a neighborhood around the point to be extracted, it is possible to provide an approximate estimate of the position of the feature with sub-pixel accuracy. These approaches are all based on the attempt to locally model the quantized image function, striving to reconstruct the information lost due to spatial quantization.

Every problem has a specific technique for extracting such information. In this section, some of them will be examined.