Welcome to the Visual Quality Testlab (VQT).

Objective quality measurements, using metrics such as PSNR, SSIM, etc., are good and straightforward indicators for assessing the visual quality of an image processing system. Most of these metrics can be reduced to simple mathematical formulas, while others are slightly more complex as they try to take into account the specific properties of the human visual system (HVS). However, these objective quality measurements do not always correlate well with actual perceived visual quality by real human observers. As such, it is important to assess the quality performance of an image processing system, using subjective quality measurements.

Our department's specifically built test room, the Visual Quality Test lab (VQT), facilitates these subjective quality measurements. In order to have the strictly controlled environment, the room was designed to conform to the most current version of the ITU-R Rec. BT.500 specification. During subjective experiments the room can be sealed off from all external influences such as unwanted light sources and all environmental noises. Inside the room, fluorescent tube lamps with a mid-daylight color temperature (6500K) generate about 64 lux of indirect illuminance. The walls, floor, ceiling and furniture of the room are all painted in matte mid-gray (RAL 7047) colors, to eliminate undesired reflections. Thus, a controlled and constant CIE standard illuminant D65 lightning condition is created for the experiments to run in optimal state-of-the-art research surroundings. Moreover, all display equipment required for the different types of tests conform to relevant industry standards by being carefully calibrated.