Hi 0
> From: [EMAIL PROTECTED]
> Subject: [Mjpeg-users] Re: [Possible SPAM] Mjpeg-users digest, Vol 1 #888 - 15 msgs
Interesting subject - wonder where that came from?
> Out of curiosity what threshold (-t) and depth (-d) values did you
>
> I used your suggested parameters, actually. (I assume you meant -l?) :
Yes, I did mean '-l' (writing mail before the 2nd/3rd cup of coffee
on the day ;)).
> yuvdenoise -r 24 -t 6 -l 2 -L 100 -C 110 -S 0
> I use -C 110 because to my eyes yuvdenoise lowers the color saturation
> (as well as shift the color a little bit).
-S 0 is the important one, it speeds things up and avoids introducing
bitnoise (quite noticeable at SVCD resolutions because the bit budget
is low and bitnoise eats into the available bits).
> BTW - Did you lower -l to improve fast motion? I noticed the default
> value of 3 left artifacts when things moved too quickly. Maybe
Not really for that reason. On clean material I didn't see the
need for the more aggressive value. For DV sources (from a
Digital8 camcoder) '-l 1 -t 6' is good, for captures from a good
source (laserdisc) '-l 2 -t 6'. The really bad sources such as VHS
get '-l 3 -t 4' (VHS is so low quality it's hard to tell the artifacts
from the original noise ;)).
For black&white movies it would be nice to kill the chroma completely
and "-C 0" is _supposed_ to do that but in my looking at the output from
yuvdenoise with a hexdump I still see the spurious chroma information
(centered around 128). So, for the few black&white movies I've
used 'yuvscaler -O MONOCHROME' in the pipeline.
> I just hadn't tried it out till now, and was very surprised that it
> lowers the bitrate so much yet I'm not sure I could tell in a double
> blind test - certainly NOT the case for yuvdenoise and
> yuvmedianfilter. Although my camera is so noisy in low light that I
> need yuvdenoise just to make it look presentable.
"yuvmedianfilter -t 0 -T 4" (leave the luma unchanged and filter
only on the chroma) has noticeably less softening of the detail but
is still fairly effective. I take that to mean that in the data I
was using most of the "noise" was in the color area.
I've noticed that (many) digital cameras do not do well in low light
situations - my old Hi8 camcorder did better I think in those cases.
More $$$ of course can take care of that - the better 3CCD cameras
have better lowlight capabilities, better picture quality and so on.
I see that Panasonic is introducing a 3chip miniDV unit for under
$1k - that's quite a breakthru (previous ones were in the $1500 to $2500
range).
Cheers,
Steven Schultz
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