Focus Issues?

[mstoetz1 0]

I have a question I hope someone can help...

 

I'm focusing a camera via a 12" tv and composite video cable and its actually quite clear.

 

But when I connect it to my DVR (QSEE QT428), and view it in CMS or its web client, the image is not very clear.

 

Does anyone know why it would be clear on a regular monitor, but not through the DVR?

 

Thanks!

Michelle

[Soundy 1]

Because viewing it on your TV is a direct analog video connection.

 

Your DVR is taking that analog signal and digitizing it, which right there makes the picture "blocky" - how blocky depends on the resolution settings. Your DVR is also compressing the video, using one form or another of "lossy" compression, which means it discards some less important visual data to save space.

 

So yes, the video quality is being reduced by the DVR - this is universal and there's no way to get away from it. Mitigate it, yes - avoid it, no.

 

To further complicate it, some DVRs re-compress the video again when you view it over the network, to reduce bandwidth requirements even more and allow for smoother streaming.

[mstoetz1 0]

Thanks for the quick reply.

 

I probably lose 20% of the clarity of the video.

 

Its too bad, since at that point you probably lose much of the ability for facial recognition.

[Soundy 1]

You'll want to check your various quality-related settings - if you're losing that much clarity, it sounds like you're recording at CIF resolution (352x240).

 

How is it if you view it on a monitor connected directly to the machine, vs. over the network?

 

You might want to check this thread as well: viewtopic.php?f=3&t=23471

[groovyman 0]

Another issue could be the screen resolution on your PC monitor. I have a couple of 19" Standard (not wide screen) LCD monitors connected to the PC I'm using right now. They are set at their native resolution (1280x1024) and Medium (125%) Display (a setting in Windows 7 that makes text and other items appear larger).

 

Live or recorded video on this system with those monitors and settings looks crappy. However, if I set the Display to normal it looks much better, but as I start to increase the live or playback size, let's say 200% - 300% of normal size so it fills the screen, the video will start to get pixelated.

 

I have another system with a quality, widescreen monitor. Live streaming & video playback on this system blows away what I get on the other system. It also looks great on my newer laptop - older laptop not so good.

 

Bottom line is there could be a variety of reasons why video doesn't look very clear on your PC. Just need to know the most likely causes and tweak both the DVR and PC to get the best possible viewing experience.

[Soundy 1]

^This is a good point as well - in short, your digital image doesn't stop at the DVR, but goes through several other stages of processing, sizing, stretching, and other degradations before you see it.

 

If you have a 1280x1024 monitor, with your DVR software, the camera window may be, say, 700x520 (just random numbers I pulled out of my arse)... so now you have a 702x480 image that you're resizing to 700x520, which will generate artifacts of its own...

 

A lot of times you see widescreen monitors on DVRs that don't do widescreen display properly... a 19" monitor is typically 1440x900 "native" resolution (the actual number of physical image-generating pixels in the LCD panel), so then you might have the 1280x1024 display being resized again to 1440x900, and stretched horizontally to fill the screen...

 

All put together, things like this can really adversely affect the image you're looking at.