SR_bicubic_test(matlab vs cv2)
This project compares the bicubic and psnr measurements in matlab and python's cv2.
Dependencies and Installation
- Python 3.6
- PyTorch 1.1
- Matlab
- opencv 3.4.2
How to use code
-
Make Down and Up scaled Images by using bicubic in various ways.
run Create_DownUpScaled_Images.m
run Create_DownUpScaled_Images_cv2.py
run Create_DownUpScaled_Images_fakeMatlab.py -
Calculate PSNR
run Get_PSNR_demo.m
run Get_PSNR_demo.py
Experiment result
Since the 'bicubic' and 'bgr2ycbcr' functions are different in cv2 and matlab,
the values are different when measuring the PSNR of SR.
The link below explains why.
https://stackoverflow.com/questions/22092744/what-is-the-difference-between-opencvs-and-matlabs-bicubic-algorithm
Original image
Matlab bicubic
cv2 bicubic
You can see the difference between the two results.
But I thankfully found that the result of xinntao's python code is exactly the same as in matlab. https://github.com/xinntao
PSNR(scale factor : 4, Set5)
| Method | PSNR(dB) |
|---|---|
| down, up scaling by matlab's BICUBIC | 28.419690 |
| down, up scaled from A by python opencv bicubic | 27.683244 |
| down, up scaled from A by Fake matlab(writen by python) | 28.419690 |
It can also be confirmed that the PSNR results of 'Get_PSNR_demo.m' and 'Get_PSNR_demo.py' are the same.