Systems and methods related to video encoding and decoding using decoder-side intra mode derivation (DIMD) are described. In an exemplary method of coding samples in a block in a video, an intra coding mode is selected based on a plurality of reconstructed samples in a template region adjacent to the block, and the samples in the block are predicted with intra prediction using the selected intra coding mode. The intra coding mode may be selected by testing a plurality of candidate intra coding modes for cost (e.g. distortion) of predicting the template region from a set of reconstructed reference samples. The mode with the lowest cost is used for prediction. In exemplary embodiments, explicit signaling of the intra mode is not required.