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plankanban / planka

The realtime kanban board for workgroups built with React and Redux.
https://planka.app
GNU Affero General Public License v3.0
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Thumbnail image quality #114

Closed mottosso closed 3 years ago

mottosso commented 3 years ago

Hi all,

Is there a way to control the image quality that ends up in the thumbnails of each card? I find it a little too blurry, especially with a display at higher resolutions/pixel densities. I can understand the diskspace/quality tradeoff, but in my case I'm happy to spend more disk space in exhange for more visibility amongst my cards. In this case, the thumbnail is 4.6 kb, even a 10x fold increase of that is very acceptible.

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nickbe commented 3 years ago

When zooming into your original image I can see that it's already somewhat blurry. Also the image contrast favors a certain degree of blurring when downsizing the image, except when I use a second step to sharpen the image afterwards. So far I didn't encounter other problems here, but I'll check with Maks if there's something we can optimize easily here.

mottosso commented 3 years ago

The browser tends to ignore pixel density from screen captures, but the card was screenshotted at 1.5x resolution scale which makes the issue a little trickier to spot.

But if you compare the thumbnail image to the text below that's about as clear I think I can make it. The text is blurry due to browser-upscaling, but does not have the JPEG artefacts found in the thumbnail, especially around the silhouettes of things like the tail or speech bubbles. That's typical JPEG quality issues. Have you considered using PNG instead?

meltyshev commented 3 years ago

I will set JPG quality to 100% and chroma subsampling to 4:4:4 for attachment thumbnails. Tested it already - a lot better result.