It should be noted that frame 340 is still being kept in storage as a long-term reference. When frame 370 is encountered, a regional change in region 301 is detected and is determined to closely match the corresponding region in frame 340 from storage. So, region 301 in frame 370 references the corresponding region in frame 340 and the remainder of frame 370 references the corresponding remaining portions of frame 360 in storage frame 370 now replaces frame 340 in storage for future reference. Alternatively, as similarly described above with respect to frames 310 and 320, in another example, only portions of frames 360 and 370 can be stored.

The compression efficiency experienced by the region-based reference frame management represented by the diagram of FIG. 4 is greatly improved over that represented by FIG. 3. In FIG. 3, compression efficiency challenges were experienced at least for frames 320, 350, and 370. In FIG. 4, the compression efficiency challenges were overcome for frames 350 and 370, resulting in greater compression efficiency and improved performance.