1. A system, comprising: a processor configured to: receive a set of data comprising at least a first tile and a second tile included in a time series of images; determine a gradient magnitude for each pixel location included in each of the first tile and the second tile; determine, for each pixel location included in both the first tile and the second tile, a measure of whether the pixel location meets a boundary criterion, at least in part by using the respective determined gradient magnitudes for the pixel location in the respective first tile and second tile; and generate as output a boundary map that corresponds to at least one of: a set of pixel locations determined to be boundary pixels, and a set of pixel locations determined to be non-boundary pixels; and a memory coupled to the processor and configured to provide the processor with instructions.