A method and image processing circuit for performing searching operations regarding an image are provided, wherein the image includes a plurality of blocks. The method includes: utilizing a grouping circuit to divide the plurality of blocks into a plurality of groups, wherein a group within the plurality of groups corresponds to a searching region within a target image, the group includes NB reference blocks within the plurality of blocks, the searching region includes NB sub-regions, and NB is an integer greater than one; utilizing a searching circuit to search for the NB reference blocks in the NB sub-regions, respectively, to generate NB searching results respectively corresponding to the NB reference blocks; and utilizing a selecting circuit to select a searching result from the NB searching results, for utilizing the searching result to represent a portion or all of the NB searching results.