http://waifu2x.udp.jp/ (not https, not safe connection but faster than the other one and has photo preset)
https://waifu2x.booru.pics/ (has no photo preset, just noise reduction and scaling)
you can use these websites to increase the quality of your images
or
https://github.com/lltcggie/waifu2x-caffe/releasesdownload the pc gui (might need to go to "App Setting" and check Use CPU)
things it can do :
remove noise
attempt to increase the resolution and quality of an image. (denoise + magnify)
note most settings are optimized for "anime styles" but the Photography and PhotoUp pre-sets work on photos too, just needs a bit more denoising
it can probably do other things too but regardless try it out and post results here? i would imagine it would be useful to boost your art quality or something