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Better jpeg scaling
Posted: Thu Mar 24, 2005 10:34 am
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
Posted: Thu Mar 24, 2005 11:46 am
by zoneminder
Can you post a screenshot? I have cameras at 352x288 and they look ok when scaled at 3/4x.
Phil
Posted: Thu Mar 24, 2005 12:49 pm
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).
DN
Posted: Thu Mar 24, 2005 1:06 pm
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
Posted: Thu Mar 24, 2005 1:11 pm
by loop
Yes, I was looking at the diagonal lines. Ok, we'll use is as it is.
Thank you.