[AG-TECH] Image quality

[Brian Corrie]

Hi Natalai,

No one has suggested this yet, but you might want to look at whether you 
are using the right setting in terms of PAL/NTSC etc. If xawtv looks 
good but vic does not this implies that is an application level problem, 
not a camera problem. If you don't have the right video settings we find 
that the image becomes almost a greyscale image etc. This might be the 
problem.

Brian


Natalia Costas Lago wrote:

> 
> Thank you for the hints, in xawtv the image is not that bad, but in VIC it's
> terrible (colors and definition), it doesnt make much difference to increase
> quality and bandwith to the maximun. I was wondering wich tricks or codecs
> do people use. Am I wrong in my thought about h261 being the only codec
> available to AG2.1.2?
> 
> 
> 
>>Nothing about your equipment, of itself, should cause any major
>>image quality deterioration.  Of course, if the camera has been
>>used before and left pointed at a bright source for a long time,
>>say in a surveillance role, it could be the problem.  Equally if
>>someone has set up the monitors for a particular application, they
>>could be the problem.  If you have a decent AV department around,
>>you could try to eliminate the camera as the problem by plugging
>>in a video signal generator instead, with it set to colour bars,
>>and see how they come out - they should really shine on a PC
>>monitor.  If they do, then try a different camera.  If they don't, look
>>at the display side of things.  Make sure you don't have any
>>excessive cable runs - many cameras don't have very powerful output
>>drivers and the first thing to go can be colour.  Also check you
>>are using proper video cable from camera to capture card - an
>>underspecified cable will lose high frequencies (say above 3 MHz)
>>more than lower ones, and so reduce the colour information.
>>
>>Cheers
>>
>>Chris
>>
>>____________________________________________________________________
>>Chris Osland                                               Office tel:
>>+44 (0) 1235 446565
>>Digital Media and Access Grid                          Medialab tel:
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>>e-mail:   C.D.Osland at rl.ac.uk
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>>Chilton, DIDCOT, Oxon OX11 0QX, UK
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>>
>>
>>
>>
>>>-----Original Message-----
>>>From: owner-ag-tech at mcs.anl.gov [mailto:owner-ag-tech at mcs.anl.gov]On
>>>Behalf Of Natalia Costas Lago
>>>Sent: 13 May 2004 08:43
>>>To: ag-tech at mcs.anl.gov
>>>Subject: [AG-TECH] Image quality
>>>
>>>
>>>
>>>
>>>Hi all,
>>>
>>>
>>>We have noticed that image color in our videostream seems to
>>>have a lack of
>>>....accuracy to reality... i've seen other video streams that seem to
>>>reflect colors better and probably in a more real way. I was
>>>wondering where
>>>in the chain we can fix that. We are using a provisional Sony EVI D30
>>>camera, pinnacle pctv pro capture cards (i've tried as well
>>>with osprey 500,
>>>osprey 100 and hauppauge wintv go). Our display grahpics card
>>>is a nvidia
>>>quadro nvs and, finally, our display right now is composed of
>>>a brand new
>>>fujitsu TFT and a plasma TV.
>>>
>>>The codecs we are using are h261 (i think h263 cant be used
>>>with AG2.1.2 so
>>>far, is there any date about when will it be available?).
>>>
>>>Can anyone give us a piece of advice where we can improve our
>>>video quality?
>>>
>>>Kind regards and thank you in advance.
>>>Natalia.
>>>
>>>
>>>-----------------------------------
>>>Natalia Costas Lago
>>>email: natalia at cesga.es
>>>
>>>Centro de Supercomputacion de Galicia (CESGA)
>>>Avenida de Vigo, s/n Campus Sur
>>>15705 Santiago de Compostela - SPAIN
>>>Tel:   +34  981 56 98 10
>>>Fax:  +34  981 59 46 16
>>>http://www.cesga.es/
>>>
>>>
> 
> 
> 
> 
> -----------------------------------
> Natalia Costas Lago
> mailto: natalia at cesga.es
> 
> Centro de Supercomputacion de Galicia (CESGA)
> Avenida de Vigo, s/n Campus Sur
> 15705 Santiago de Compostela - SPAIN
> Tel: +34  981 56 98 10
> Fax: +34  981 59 46 16
> http://www.cesga.es/
> 
>