Peak Signalto-Noise Ratio (PSNR) is a widely used metric for asseming thor quality of compresed or rekonstrukted images. It compares thee original image with thee processed image to quantify the level of distortion or noise introed during procesing. PSNR is expressed in decibels (dB), with higer values indicating better image quality.

Understanding PSNR

PSNR is calculated based on thoe Mean Squared Error (MSE) between een thee original and thee processed image. Te formula for PSNR is:

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Where MAX is thee maximum possible pixel value of thee image. For 8-bit images, MAX is255.

Calculating PSNR Step- by- Step

To compute PSNR, follow these steps:

  • Vypočítejte si, že MSE by averaging that e squared differences s between corresponding pixels of the original and processed images.
  • Určete maximální hodnotu pixelu (např. 255 for 8-bit images).
  • Aplikujte tento vzorec PSNR using te MSE and MAX value.

Praktická posouzení

Wile PSNR is simple to o compute and widely used, it does not always correlate perfectly with perfeivek image quality. Factors such as human visual perception are not directly accounted for in PSNR calculations. Therefore, it is often used alongside othermetrics like Structural applitary discrity discrix (SSIM).