the brisque model seems yield wrong result quite often. I have original png image, jpeg compressed with 90% quality, jpeg with 60% quality.
The computed score is:
- (23.201696395874023, 0.0, 0.0, 0.0) for png
- (19.102746963500977, 0.0, 0.0, 0.0) for high quality jpg
- (17.447845458984375, 0.0, 0.0, 0.0) for low quality jpg
If I get the paper correct, the higher the score the lower the quality.
png:

high quality jpeg:

low quality jpeg:
