Difference between SNR and PSNR

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.

1. Why is PSNR used?
2. What is the difference between PSNR and SSIM?
3. What is the difference between SNR and CNR?
4. What is PSNR in signal processing?

Why is PSNR used?

Description. 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 difference between PSNR and SSIM?

PSNR is used earlier than SSIM, is easy, has been widely used in various digital image measurements, and has been considered tested and valid. SSIM is a newer measurement tool that is designed based on three factors i.e. luminance, contrast, and structure to better suit the workings of the human visual system.

What is the difference between SNR and CNR?

SNR versus CNR

Contrast-to-noise ratio (CNR) is a measure used to determine image quality. CNR is similar to the metric signal-to-noise ratio (SNR), but subtracts a term before taking the ratio. Signal-to-noise ratio (SNR or S/N) compares the level of a desired signal to the level of background noise.

What is PSNR in signal processing?

Peak signal-to-noise ratio (PSNR) is an engineering term for the ratio between the maximum possible power of a signal and the power of corrupting noise that affects the fidelity of its representation.