This post is a useful link to Tampere Image Database (TID) and visual quality metric test suite, that I would like to have close at hand.
TID is intended for evaluation of full-reference image visual
quality assessment metrics. TID allows estimating how a given
metric corresponds to mean human perception. For example, in
accordance with TID2008, Spearman correlation between the metric
PSNR (Peak Signal to Noise Ratio) and mean human perception (MOS,
Mean Opinion Score) is 0.525.
How to test your metric?
Step 1. Download the TID2008.
Step 2. Calculate values of your metric
for each distorted image of TID2008.
Step 3. Use included software
("spearman.exe" or "kendall.exe") for calculate a correlation between your metric and MOS.
In case of publishing results obtained by means of TID2008 please
refer to one of the following papers:
(full description of TID2008)
 N. Ponomarenko, V. Lukin, A. Zelensky, K. Egiazarian, M. Carli,
F. Battisti, "TID2008 - A Database for Evaluation of Full-Reference
Visual Quality Assessment Metrics", Advances of Modern
Radioelectronics, Vol. 10, pp. 30-45, 2009.
(a short description of TID2008)
 N. Ponomarenko, F. Battisti, K. Egiazarian, J. Astola, V. Lukin
"Metrics performance comparison for color image database", Fourth international
workshop on video processing and quality metrics for consumer electronics,
Scottsdale, Arizona, USA. Jan. 14-16, 2009, 6 p.