What is "perceptually lossless"?
Whenever an image that is sent to a remote client is not pixel exact, it is considered lossy rather than lossless. The human eye is not always able to perceive these lossy differences. For example, the human eye is much less sensitive to errors in the color blue than in the color green. The PCoIP lossy compression algorithms make use of these human characteristics to deliver a lossy image that is perceptually lossless even though the image is not pixel exact.
HP Anyware uses a mixture of objective and subjective measures to determine at which Q level of quality a PCoIP connection is perceptually lossless. The objective measures we use are Peak Signal to Noise Ratio (PSNR) and Structural Similarity (SSIM). We supplement both those measures with assessments by our most stringent customers. Using these measures, most video content you view on the TV or computer is approximately a Q80 level of quality. For most image content, PCoIP will use Q90 level of quality. For use cases with the highest demand, such as CAD drawings or raw video footage, you can configure PCoIP for Q100 level of quality. Naturally, as you increase the image quality level, the protocol will require higher bandwidth.
See Also:
What is the impact of minimum and maximum initial image quality on a PCoIP Session?