basicvsr calculate y-channel psnr

[youyoubud]

In basicvsr_vimeo90k_bi.py:
train_pipeline loads image in RGB channel order, and calculates y-channel psnr.
but when computing psnr for 'Y', the images are assumed to be in BGR order.
why?🙏

`def psnr(img1, img2, crop_border=0, input_order='HWC', convert_to=None):
"""Calculate PSNR (Peak Signal-to-Noise Ratio).

Ref: https://en.wikipedia.org/wiki/Peak_signal-to-noise_ratio

Args:
    img1 (ndarray): Images with range [0, 255].
    img2 (ndarray): Images with range [0, 255].
    crop_border (int): Cropped pixels in each edges of an image. These
        pixels are not involved in the PSNR calculation. Default: 0.
    input_order (str): Whether the input order is 'HWC' or 'CHW'.
        Default: 'HWC'.
    convert_to (str): Whether to convert the images to other color models.
        If None, the images are not altered. When computing for 'Y',
        the images are assumed to be in BGR order. Options are 'Y' and
        None. Default: None.

Returns:
    float: psnr result.
"""`

[Z-Fran]

Hi, you can view these codes. Before calling psnr(), we will use tensor2img() to convert the image to BGR. And we recommend you use new version MMEditing

[youyoubud]

thank you! 🌹