Re: [MLUG] Followup on WebCam.

["Christian M. Cepel" <EMAIL:PROTECTED>]

Zack and Mark.. Thanks for the replys... Here's the thing I don't 
understand.  This happens even when no compression is applied.  Like you 
say, it's not using a true lossless format.  What I'm wondering is... 
Why?  I've taken snapshots using the software that came with the camera, 
and I get the same thing.  Could the Hardware be doing this?  I wouldn't 
think anybody would develop a hardware/driver interface that would 
intentionally throw out data it's already captured.  Very odd.  Very 
frustrating.

If I had my way, I'd use my Kodak DC4800, but Kodak saw fit to flip the 
bird at their customers had has refused for the past 3 years to allow 
method of accessing the camera other than their vile 'easy share' 
software.  People are begging for Twain, or similar.  Kodak could care less.

It's driving me crazy.  I keep messing with the focus, 'cause I keep 
thinking I can improve the crispness.

 //Christian

vapor wrote:

> It is a result of the jpeg.  Unfortunately, there is no one standard 
> for lossless jpeg... there's 3 different standards if I recall 
> correctly, and the ISO standard is the only one that is truely 
> lossless.  Even so, to get lossless out of the image you need to 
> decompress it back into a truely lossless format (not jpeg).  The ISO 
> standard only works well with smoothly-changing-in-tone images and 
> still typically compresses the shown image by 2:1, which I would guess 
> is what is happening as "HamsterCam.jpg" is only 77k.  There's no real 
> point to having a lossless jpeg as you still need to decompress it to 
> utilize the data available.
>
> Regards,
> Zach
>
> Christian M. Cepel wrote:
>
>> http://HamsterCam.bramblethorne.org/
>>
>> Its been live for about a week, and underwent the normal few days of 
>> shakedown for any new gadget.  Its proving popular with the 'hamster 
>> community' :)
>>
>> Hardware:
>> Ended up getting a Logitech Messenger IM cam.  Not really happy with 
>> it, but considering I bought the $20 off brand and then had to return 
>> it and came home with something with true 640x480 CMOS 30fps, I guess 
>> I didn't do too badly.  The one thing I cannot figure out is why if 
>> it takes at 640x480 CMOS TRUE, why I'm seeing macropixeling in an 
>> uncompressed image.  Here's the thing.  I would expect 640x480 
>> distinct pixels, but I do not expect them to be grouped  and aliased 
>> into little blocks of 64 pixels, 8 per side.  Here's what I mean.
>>
>> http://hamstercam.bramblethorne.org/HamsterCam-Macropixel.jpg
>>
>> Anyone know why this is?  I'm considering trying a webcam in linux 
>> just to see if its something other than hardware.
>>
>> Wife doesn't want to leave the machine in Linux all the time so was 
>> forced to find Windoze software to drive it.  Ended up using Active.  
>> Fairly happy with it except that it won't do incremental numbers on 
>> the FTP setup with the oldest being deleted, keeping only the newest 
>> X shots.  Came with a slim little Java applet that I will keep even 
>> if I switch software later on.  Would be happier if it (or the camera 
>> hardware) would allow 90deg rotation instead of just 180, and if one 
>> could set multiple events of the same type (multiple FTP 
>> destinations/tasks).
>>
>> Anyways...
>
>
>
>
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-- 

|Christian Marcus Cepel           | And the wrens have returned &
EMAIL:PROTECTED icq:12384980 | are nesting; In the hollow of
371 Crown Point, Columbia, MO    | that oak where his heart once
65203-2202 573.999.2370          | had been; And he lifts up his
Computer Support Specialist, Sr. | arms in a blessing; For being
University of Missouri-Columbia  | born again. --Rich Mullins|

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