Image parameters for SRGAN

In some implementations of SRGAN I’ve noticed, that datasets consist of the high-resolution images and the low-resolution images are created later by, e.g. resizing (decreasing the size) hr-images. However, e.g. I have a dataset of both hr-images and lr-images, all of them are of the same size but lr-images are of lower quality (less details, blurred). Is it proper to use SRGAN in such case or should I use another way of image enhancing?