contrast enhancement?

[wwuster]

I've got some raw .dv video from a digital tape player. If I play the tape on a tv the colors ar bright and the video looks good. If I play the raw video (obtained with dvgrab in linux) on my lcd monitor the video looks muddy or washed out. It looks like there is a light haze over it. Otherwise it looks fine. I've tested converting the raw video to xvid using transcode, mencoder, and ffmpeg and the xvid file also looks washed out. I've tried adjusting the monitor settings and the video card settings but can't find anything that makes it look like it does on a TV.

Can someone explain why the video looks so different on the computer?

Is there any filter that would enhance the contrast and brighten up the colors for a LCD screen?

thanks,
William

[JohnnyMalaria]

Can someone explain why the video looks so different on the computer?

http://en.wikipedia.org/wiki/Gamma_correction

If your video card has separate controls for the overlay, you can adjust the gamma settings.

[wwuster]

I've tried running 'nvidia settings' to play with gamma settings and can improve the look some, but still can't get it to look as good as on a TV. I'll try it some more. But does anyway know of any contrast enhancement filters? I've also tried may gamma,brightness,contrast settings in transcode etc but can't get the video to look as goot. I've seen some good results with something called 'HDR filters', but can't find one to use. I'm running linux mostly but can run xp also.

thanks,
William

[edDV]

Sounds like the video in the file was captured NTSC (7.5-100IRE) and that linux program or the recording VCR was expecting 0-100IRE.

That results in black being mapped to level 32 instead of 16 hence the washed out look.

Watch this tutorial and then ask again if there are questions
http://pro.jvc.com/pro/attributes/prodv/clips/blacksetup/JVC_DEMO.swf

The issue was also disussed in many other threads including this one
https://forum.videohelp.com/viewtopic.php?t=277980&highlight=jvc+black+level

Once levels are set, fine tune with gamma.

[JohnnyMalaria]

I'm running linux mostly but can run xp also.

thanks,
William

Under XP, you could use our Enosoft DV Processor - it will let you adjust contrast (and brightness + more) in real time while transferring the DV from camcorder to hard drive.

[wwuster]

Sounds like the video in the file was captured NTSC (7.5-100IRE) and that linux program or the recording VCR was expecting 0-100IRE.

That results in black being mapped to level 32 instead of 16 hence the washed out look.

Watch this tutorial and then ask again if there are questions
http://pro.jvc.com/pro/attributes/prodv/clips/blacksetup/JVC_DEMO.swf

The issue was also disussed in many other threads including this one
https://forum.videohelp.com/viewtopic.php?t=277980&highlight=jvc+black+level

Once levels are set, fine tune with gamma.

I looked at that thread and the example of a "washed out" frame looks like what I'm seeing. I have a video tape that was recorded with a Canon GL2 by someone else. I captured the raw video from the tape using a Sony DSR-11 tape player using firewire. Do you know what black levels these devices use and is there a free utility to find out what black level the downloaded .dv file is?

William

[edDV]

Sounds like the video in the file was captured NTSC (7.5-100IRE) and that linux program or the recording VCR was expecting 0-100IRE.

That results in black being mapped to level 32 instead of 16 hence the washed out look.

Watch this tutorial and then ask again if there are questions
http://pro.jvc.com/pro/attributes/prodv/clips/blacksetup/JVC_DEMO.swf

The issue was also disussed in many other threads including this one
https://forum.videohelp.com/viewtopic.php?t=277980&highlight=jvc+black+level

Once levels are set, fine tune with gamma.

I looked at that thread and the example of a "washed out" frame looks like what I'm seeing. I have a video tape that was recorded with a Canon GL2 by someone else. I captured the raw video from the tape using a Sony DSR-11 tape player using firewire. Do you know what black levels these devices use and is there a free utility to find out what black level the downloaded .dv file is?

William

If it was recorded from the camera the scaling would be 0-100IRE (digital 16-235). If the camcorder was used to record broadcast NTSC 7.5-100IRE (composite or S-Video in) then black would be found at digital level 32 and white at level 235 or 255 depending on the camcorder. Since the Mpeg2 encoder wants to see black at 16, the resulting signal will look washed out.