1. A method, comprising: performing, by a computing device: generating target luminance values for each of a plurality of blocks for an image, wherein said generating is based at least in part on a brightness representation of the image; generating luminance histogram information for each of the plurality of blocks; for each of the plurality of blocks of the image: determining one or more neighboring blocks for the block; determining, for the block, one or more tone adjustment values that when jointly applied to the respective histogram information for the block and each of the one or more neighboring blocks generate new luminance values for the block and each of the one or more neighboring blocks that match the respective target luminance values for the block and each of the one or more neighboring blocks; and performing one or more tone adjustments on the image according to the one or more tone adjustment values.