1. A method, comprising: displaying a digital image on an electronic device, wherein the electronic device is configured to receive sets of gestural inputs; receiving, via the electronic device, a gestural input set, wherein the gestural input set comprises a plurality of gestures, and wherein each given gesture of the received plurality of gestures: corresponds to one of multiple different regions within the digital image; and specifies a respective type of image processing constraint for processing the corresponding one of the multiple different regions within the digital image, wherein the respective type of image processing constraint depends on the gesture type of the given gesture; wherein the plurality of gestures in the received gestural input set include multiple different types of gestures such that the received gestural input set collectively specifies multiple types of image processing constraints; analyzing the received gestural input set to determine, for each region of the multiple different regions, the respective type of image processing constraint for processing the region, as specified by the given gesture of the received plurality of gestures that corresponds to the region; and subsequent to receiving the plurality of gestures including multiple different types of gestures, performing a particular image processing operation on the multiple different regions within the digital image according to each region's respective specified image processing constraint as specified by the type of gesture applied to that region.