With dynamic region of interest (ROI), the video stream is analyzed to identify the areas of greatest interest, that is, those with detail or motion. These areas are compressed to a lesser degree, to preserve detail, while other areas are compressed much more. In the example image below, the areas containing the man and the text are compressed at the level 30, whilst the rest of the image is compressed harder, at level 60.
Figure 2: Areas of potential interest are compressed less severely.