mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-24 13:31:07 +00:00
bfcb95b297
* fixup! Format Python code with psf/black push * Create codespell.yml * fixup! Format Python code with psf/black push
44 lines
1.2 KiB
Python
44 lines
1.2 KiB
Python
"""
|
|
Peak signal-to-noise ratio - PSNR - https://en.wikipedia.org/wiki/Peak_signal-to-noise_ratio
|
|
Source: https://tutorials.techonical.com/how-to-calculate-psnr-value-of-two-images-using-python/
|
|
"""
|
|
|
|
import math
|
|
import os
|
|
|
|
import cv2
|
|
import numpy as np
|
|
|
|
|
|
def psnr(original, contrast):
|
|
mse = np.mean((original - contrast) ** 2)
|
|
if mse == 0:
|
|
return 100
|
|
PIXEL_MAX = 255.0
|
|
PSNR = 20 * math.log10(PIXEL_MAX / math.sqrt(mse))
|
|
return PSNR
|
|
|
|
|
|
def main():
|
|
dir_path = os.path.dirname(os.path.realpath(__file__))
|
|
# Loading images (original image and compressed image)
|
|
original = cv2.imread(os.path.join(dir_path, "image_data/original_image.png"))
|
|
contrast = cv2.imread(os.path.join(dir_path, "image_data/compressed_image.png"), 1)
|
|
|
|
original2 = cv2.imread(os.path.join(dir_path, "image_data/PSNR-example-base.png"))
|
|
contrast2 = cv2.imread(
|
|
os.path.join(dir_path, "image_data/PSNR-example-comp-10.jpg"), 1
|
|
)
|
|
|
|
# Value expected: 29.73dB
|
|
print("-- First Test --")
|
|
print(f"PSNR value is {psnr(original, contrast)} dB")
|
|
|
|
# # Value expected: 31.53dB (Wikipedia Example)
|
|
print("\n-- Second Test --")
|
|
print(f"PSNR value is {psnr(original2, contrast2)} dB")
|
|
|
|
|
|
if __name__ == "__main__":
|
|
main()
|