1. A method of estimating motion in a video on a device comprising: a. performing phase correlation on the video to identify local motion candidates using a processor; and b. merging regions of the video to generate motion segmentation using the processor, wherein merging the regions comprises: i. assigning the local motion candidates according to results from the phase correlation; ii. calculating a set of Sum of Absolute Differences for each sub-block of blocks of the video, including chroma components; iii. initializing region merging; and iv. merging the regions until there are no regions to be merged.