Peak Signal- to- Noise Ratio (PSNR) is a common metric used to o evaluate thee quality of compresed images. It measures thee differente been een thee original and thee compresed image, proving an indication of how much quality has been logt during compression.

Co to je?

PSNR is expressed in decibels (dB) and compares thee maximum possible pixel value of an image to thee error introded by compression. Higher PSNR values generate indicate better image e quality, with less distortion.

Calculating PSNR

Te calculation of PSNR involves two main steps: computing the Mean Squared Error (MSE) and then converting it to PSNR. Te formula for MSE is:

CLAS1; CLAS1; CLAS3; CLAS3; CLAS3; CLAS3; CLAS3; CLAS3E = (1 / (m × n)) × Σ( CLAS1; I (x, y) - K (x, y) CLAS3; CLAS1; CLAS1; CLAS1; CLAS3; CLAS3CLAS3CLAS3CLAS3CLAS3CLAS3CLAS3CLAS3CLAS3CLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLASLAND;

kde I (x, y) is te original al image pixel value, K (x, y) is te compressed image pixel value, and m and d n are the dimensions of thee images.

Once MSE is calculated, PSNR is determinaud using thee formula:

CLANE1; CLANE1; CLANE1; CLANE3; CLANE3; CLANE3; CLANE3; CLANE3; CLANE3; CLANE3; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c; CLANE3c)

Interpreting PSNR Values

PSNR values typically range from 20 dB to 50 dB. Values estate 30 dB are generaly consided accepable for mogt applications, with hicer values indicating better quality. However, perceptual quality may vary consideing on the image e content and viewer sensitivity.

Použitelnost

PSNR is widely used in image compression, video encoding, and transmission systems to evaluate and compate thee effectiveness of different algoritms. It provides a quick and objective measure of image fidelity after processing.