Details about test set construction

[k-zha14]

Hi, guys! Thanks for your meaningful and interesting works! I am a newbie in this field and encounter some puzzles in test set construction.

As stated in Sec. 4.2, 'Specifially, for images from[5, 29, 68], we crop them at the center to obtain patches with 128x128 resolution.'([5]->RealSR, [29]->DPED-iphone, [68]->DRealSR), I think the 128x128 crop operation should be applied at the LR images, which is paired with 512x512 operation on HR images. Is it right?

BTW, I notice that both RealSR and DRealSR have provided the X2, X3 and X4 datasets. I wonder whether the aforesaid operation only acted on the X4 datasets.

As for DPED-iPhone dataset, these are total 29 x 3 = 87 High-Resolution test images from 3 devices, i.e. blackberry, iphone and sony. My questions are: 1) are the total 87 images used? 2) we treat these images as the LR, and just crop the 128x128 center patch from these high-resolution images?

Thanks for you help!

[IceClear]

1. Correct.
2. We use x4 data for 128 to 512.
3. (1) We use all the test images. (2) Correct.