Kuirl / sipi integration

Dear all,

context: we set up a kuirl instance to serve as a default resource viewer and ark final resolver.

It seems that the sipi/openseadragon integration maintains a resolution as image quality, so if I look at a picture in restricted view I see the whole document as blurred as it is displayed with a low resolution.

Apparently the resolution is absolute, so if I zoom in, I get a tile at the same resolution.

Finally, if I zoom close enough, I get a small tile at the full resolution.

Isn’t it so?

maybe I was not very clear: setting the restricted view as a max picture size (blurring comes from reducing the original picture to the restricted-view 128 pixel width) is not enough with a iiif server that makes it possible to request tiles of the said size because it then comes at full resolution.

For example, here are two views of the same image (same url) seen respectively in a session with full rights and another with restricted rights, requested resolution is set at “full”, response is at 300 ppp so size varies according to the rights:

it might not be a surprise that imagemagik reports the last two views as being the same image.

any thought on that @subotic, @lrosenth, @kilchenmann, @flavie.laurens ?

No idea… I think this is a question for @lrosenth

Dear all, should I write a user story about this?

to sum it up, we can set a maximum image size for restricted view in knora, defined like in the example above as 128x128 pixel.

As the images we browse are much bigger, the downscaling makes them blurred.

The problem is that when we zoom in, as knora-app allows us to, we get to smaller portions of the image until we reach a portion of the image that is 128x128 pixels and them we see this portion of the image at its full resolution, without being blurred by downscaling.

So I could for example:

  • see a portion of the image that I would have liked blurred (even though I guess it should not
    replace anonymisation)
  • programmatically retrieve the whole picture at full res by requesting the image by tiles of 128x128

what do you think?

I suggest opening a Sipi issue about this in GitHub:

thanks, doing so now :wink:

while doing so and documenting the problem, it came to my attention that the limit passed to kb:projectRestrictedViewSize is actually the {size} in the iiif protocol.

Crazy cool :slight_smile:

so the answer to our problem is not to pass a max size (meaningless to us when you can zoom) but a max resolution, which is possible with the size passed as pct:n, from iiif documentation:

pct:n The width and height of the returned image is scaled to n% of the width and height of the extracted region. The aspect ratio of the returned image is the same as that of the extracted region.

And I therefore recommand that the default value if changed from !96,128 to pct:3.

Sounds good. Can you open an issue on YT so that it does not get lost?