Results for DivX (MPEG-4) encoding

Below we show a comparative study on one video clip, looking at all combinations of the model parameters described above.

• Video compression was performed using the mencoder program, using libavcodec and mpeg4 (DivX 4/5) settings.
• The original clip encoded as DivX has a file size of 3.2 MB (3359592 bytes).
• Presentation of the results below is the same as for the MPEG-1 results above. The demo clips have not been re-created since they are essentially the same as the MPEG-1 demos above.

Saliency Competition	Object Segmentation	Pyramid Depth 2				Pyramid Depth 4				Pyramid Depth 6
		Continuous	1 Fovea	3 Foveas	5 Foveas	Continuous	1 Fovea	3 Foveas	5 Foveas	Continuous	1 Fovea	3 Foveas	5 Foveas
Maxnorm	None	70.7%	65.8%	70.7%	73.1%	60.1%	57.5%	61.8%	64%	56.9%	54.8%	58.3%	60.3%
	FeatureMap		76%	90%	94.3%		68.2%	82.6%	89.9%		65.4%	81.3%	89.7%
FancyOne	None	61%	65.2%	70.8%	74%	55.9%	57%	61.7%	64.4%	54.2%	54.4%	58.3%	60.8%
	FeatureMap		69.4%	78.8%	82.9%		60.7%	69.9%	74.2%		57.5%	66.6%	70.9%
Fancy	None	57.3%	65.7%	71.7%	73.7%	53.6%	56.7%	62.1%	64.3%	53.1%	53.9%	58.6%	60.8%
	FeatureMap		68%	75.6%	77.8%		58.9%	66.2%	68.2%		55.7%	62.5%	64.6%

The gains in file size using our multi-foveation technique are not as high as with MPEG-1 encoding, but the trends are similar. Note that the overall quality of the original clip itself is lower with this encoder than with the MPEG-1 encoder. Pyramid depth 4 and continuous or 3 foveas seems to be an overall visually-pleasant setting.