Entropy based Saliency detection

This function finds the salient regions in a video using entropy measurement.

At every pixel location in the frame, entropy is found for a patch of a fixed size (user i/p). The locations with an entropy above a threshold (user i/p) are detected as salient.
Limitations:
1. fixed scale (no scale adaptation )
2. fixed threshold
3. Each frame is processed independently
4. Multiple detections
5. slow