Why is PSNR used for image quality metrics instead of SNR?

1. What is the difference between PSNR and SNR?
2. Why is PSNR used in image processing?
3. What is the use of PSNR?
4. Which is better PSNR or SSIM?

What is the difference between PSNR and SNR?

SNR is defined relatieve to signal while PSNR is defined relative to peak dynamic range, i.e. 255 for an 8 bit image. SNR is badly defined for homogeneous images so for reconstruction evaluation often PSNR is preferred.

Why is PSNR used in image processing?

The PSNR block computes the peak signal-to-noise ratio, in decibels, between two images. This ratio is used as a quality measurement between the original and a compressed image. The higher the PSNR, the better the quality of the compressed, or reconstructed image.

What is the use of PSNR?

PSNR is most commonly used to measure the quality of reconstruction of lossy compression codecs (e.g., for image compression). The signal in this case is the original data, and the noise is the error introduced by compression.

Which is better PSNR or SSIM?

Based on the results of tests on this research SSIM has a better sensitivity to detect distortions that occur due to embedding messages on steganographic color images when compared with PSNR, this is due to the way SSIM works that are designed based on the human visual system.