The objective method

The objective quality assessment method is presented first. For monochrome image (8 bits per pixel), the Peak Signal to Noise Ratio is defined by:

where Mean Square Error is:

and

,

are the values of the decoded and original pixels at position (x,y) respectively;

X and Y are the line and column sizes.

For color images, PSNR values for all components are usually presented.

For video, the error for all frames is averaged; thus giving one PSNR for whole sequence. Alternatively, PSNR for every frame can be reported, usually in the plot form.

	The objective method is:
+	fast
-	too simple for human sensitivity modeling

According to the International Telecommunication Union Recommendation [BT.813] PSNR is used when similar processing algorithms are compared.