Described herein is a method and system for video format conversion. Aspects of the current invention may convert decoded video data from 4:2:2 format to 4:4:4 format. Aspects of the current invention may also convert decoded video data from 4:2:0 format to 4:4:4 format. Aspects of the current invention may further convert decoded video data from 4:2:0 format to 4:2:2 format. Aspects of the current invention may provide a region-aware conversion system that monitors the edges of mosaic windows in order to apply proper boundary conditions during the conversion process.