Table 4.1.2 combines both sets of scores for each picture used in the experiment. All figures are measure in the units of JPEG Compression index. Table 4.1.2 shows the improvement in compression ratio when different cut-off points are used; a JPEG compression index of 75 was used as the baseline. Finally table 4.1.2 shows the probabilities and significance that the scores generated across subjects and between pictures are draw from the same population. Clearly, in all cases but one the images can be said to have different JPDs.
1st and 2nd Set Combined (JPEG index) | ||||
mean | sd | wse | wie | |
face | 27.13 | 8.37 | 8.22 | 13.65 |
tree | 18.10 | 10.18 | 7.48 | 18.43 |
map | 25.06 | 8.92 | 9.85 | 18.31 |
room | 31.40 | 8.92 | 6.02 | 10.63 |
all | 25.42 | 8.48 | 7.89 | 12.95 |
wse=within subject mean squared err | ||||
wie=within image mean squared error |
mean+2*sd | 42.38 | 57% |
mean+sd | 33.90 | 78% |
mean | 25.42 | 113% |
sets | P of Similarity | Significance |
face-tree | 3.26e-09 | High |
face-map | 0.0724 | None |
face-room | 4.18e-05 | High |
tree-map | 2.41e-05 | High |
tree-room | 5.08e-10 | High |
map-oom | 1.21e-06 | High |