An image correspondence determining method is provided that includes the steps outlined below. A first image and a second image are concatenated to generate a concatenated image having global information. Features are extracted from the concatenated image to generate a plurality of feature maps and the feature maps are divided into first feature maps and second feature maps. First image patches are extracted from the first feature maps corresponding to a first region and second image patches are extracted from the second feature maps corresponding to a second region. The first and the second image patches are concatenated to generate concatenated image patches. A similarity metric is calculated according to the concatenated image patches to determine a similarity between the first region and the second region.