PFF file support about dezoomify-rs

[look2020]

@lovasoa , this is really an amazing tool to download very large images! I also found it can even save those large dimension (over 30000 pixel) images to JPG format and the file size is much much less than that of the same image downloaded via http://ophir.alwaysdata.net/dezoomify/dezoomify.html. This is going to save my hard drive space. Great work!

[lovasoa]

This looks like a pff image. I do not have the time to check right now, but I think you can download the whole file and then convert it to jpeg with https://github.com/lovasoa/pff-extract

[lovasoa]

I added support for zoomify PFF in dezoomify-rs. This will be available in version v1.7.0, you will be able to download it in a few minutes, once it finishes building.

[lovasoa]

(the quality of this preview has been reduced to fit on github. see the image in full quality on wikimedia)

[lovasoa]

Be careful when saving large JPEG images, though. The JPEG format limits image sizes to a maximum of 65,535×65,535 pixels.