Challenge image quality - artefacts due to dpr processing?

Started Jan 20, 2013 | Discussions thread
chrisby OP Regular Member • Posts: 251
RaptorUK, OldArrow - Challenge image quality - artefacts due to dpr processing?

OldArrow wrote:

chrisby wrote:


A thought just occurred to me . . . is it an issue similar to burn-in that we used to get with CRT monitors ? I know there is a similar effect that happens with LCD but the effect is not permanent. Try looking at your image again in Photoshop but zoom in a little so you can move the image around to different parts of your display to see if the artefacts move with the image or not.

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Take a look at my album . . .

Interresting thought, but I cannot see the blockiness in Photoshop, only at dpr.

The thumbnail in my dpr gallery shows allready the blockiness. After clicking on it the next size shows also mosaic, but with rearranged patterns. Each further expanding shows each time blockiness, but different artefacts.

I am afraid Fil is right: I must get someone infront of my pc with more expertise than I have.


If you upload to pages other than DPR... it would be interesting to know whether the same experience repeats elsewhere. Try that, maybe. Then you could determine if it is uniquely DPR-related or something to do with the web presentation. I trust you run the latest version of FireFox (v18.0.1).

Also, try outputting from Photoshop with less compression, as JPEGs are generally compressed by reducement of fineness: the more you compress the final image the less nuances remain...

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Thank you very much again for your engagement! I promised to share the outcome, here is the feed back.

I have only access to the affected laptop on (some) weekends (2nd resisidence), but had now the opportunity to check with some experts.

It seem to be the resolution settings of the laptop which doesn't allow to choose the optimal value. So due to some interpolation the described artefacts occur.

It happens also on other pages than DPR, but nearly not noticeable.

So it has nothing to do with DPR.



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