How iiifhosting site processing images to up/down scale to make it compatible to iiif?

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My question is regarding IIIF. I am using iiifhosting.com but now i want to setup my own server. I want to know how iiifhosting.com processing my images to high resolution?

I have uploaded an image of 2000x1000 and when i get info.json i got width: 11658, height: 6112. Check this url.

http://bafdev.iiifhosting.com/iiif//e6ebb551407a5c64903d100ab8ba9199bb264d1c17cdcf0a9e745cd6c5aea432/info.json

When i try to get full image and save it its just only 1000x524

http://bafdev.iiifhosting.com/iiif//e6ebb551407a5c64903d100ab8ba9199bb264d1c17cdcf0a9e745cd6c5aea432/full/full/0/default.jpg

I want to know how iiifhosting doing this? Any clue?

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Qudrat Ullah On

1- iiifhosting is not upscaling images. It only shows image information which image have. There is no conversion in image to high resolution. In info.json you are getting image info how much width height it has and tiles sizes. Tile sizes formula is (smallest dimension) * 1/2n > endpoint.iiif.min_tile_size

endpoint.iiif.min_tile_size is which you set in cantaloupe.properties file default is 512x512

2- http://bafdev.iiifhosting.com/iiif//e6ebb551407a5c64903d100ab8ba9199bb264d1c17cdcf0a9e745cd6c5aea432/full/full/0/default.jpg

Regarding your second point there is restriction to get full resolution image on iiif hosting so you cant get full image of their client files. Therefore they are serving maximum of 1000x1000 image.

Second thing is if iiifhosting client have 2gb images (very high res) and you request 100 images on your site than it will overwhelm image server.