App generates foreground mask for rgba image, integrated into labeling UI (the first version can be without UI)
features:
- keep only top-K biggest connected components
- highlight pixels with medium opacity
- show stats for image (pixels with opacity 255 (count / percent), pixels with opacity 0 (count / percent), number of connected components) -to image metadata in v0
- opacity threshold
- add fg bitmap
- ignore image if condition
example visualization - http://kaiminghe.com/cvpr10/index.htm
