About challenge metric, SSIM

It says on the website(http://fastmri.org/submission_guidelines) that "The metric is calculated using the measure.compare_ssim function from the skimage python module with default parameters.’

The default parameters of compare_ssim are below.
compare_ssim(X, Y, win_size=None, gradient=False, data_range=None, multichannel=False, gaussian_weights=False, full=False, **kwargs)

But, on the github(https://github.com/facebookresearch/fastMRI/blob/master/common/evaluate.py), it says that
def ssim(gt, pred):
return compare_ssim(
gt.transpose(1, 2, 0), pred.transpose(1, 2, 0), multichannel=True, data_range=gt.max()
)

That is, “multichannel=True, data_range=gt.max()” is different from default parameters.
Which is correct?

Thanks

Good catch. The SSIM values are computed using the code that you linked to. We will update the submission guidelines to reflect that.