Better jpeg scaling

Support and queries relating to all previous versions of ZoneMinder
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loop
Posts: 69
Joined: Thu Nov 06, 2003 3:10 pm

Better jpeg scaling

Post by loop »

I'm capturing at 352x288 but I'd like to display streaming jpegs at 75% scale size. But the scaled image is distorted. Is it possible to scale it and get a good looking streaming image, like if I would resize it in Photoshop? Perhaps some antialias parameter somewhere in source code could be added ?

DN
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zoneminder
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Post by zoneminder »

Can you post a screenshot? I have cameras at 352x288 and they look ok when scaled at 3/4x.

Phil
loop
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Joined: Thu Nov 06, 2003 3:10 pm

Post by loop »

Hi Phil. I've sent you 100% and 75% images over email (didn't know how to include them in a post reply).

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zoneminder
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Post by zoneminder »

I've had a look at them, and they look more or less ok to me. I don't know if you are referring to the squished timestamp (which you can configure to be put on after scaling), or the 'stepped' effect on diagonal lines. Unfortunately this is a consequence of dropping 1 in 4 pixels horizontally and vertically. I think antialiasing streamed images in realtime might put an unacceptable load on the system.

Phil
loop
Posts: 69
Joined: Thu Nov 06, 2003 3:10 pm

Post by loop »

Yes, I was looking at the diagonal lines. Ok, we'll use is as it is.
Thank you.
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