For discussing IP and HD-SDI based systems: Cameras, Software and NVR's
Sun May 04, 2014 2:19 am
Hi All. Hope this the the appropriate place to post.
Long time lurker first time poster.
I was hoping my security worries would not rear their ugly heads but they did.
my motocycle was stolen out of sight of my equipment but i was fortunate enough to have 2 neighborcam who caught it on video ~ 2am the video is decent resolution (assuming low grade outdoor HD camera) .
Question- how can detect exact resolution/framerate of exisiting footage?
Im using regular video players (windows media,VLC,imovie ) but stopping it frame by frame results in the images beeing too blurry to make out the license plate of a motorcycle. Basically 2 guys on a bike ..one towed the other on my bike .
I have several sources of vid but i think the problem is getting clear image frame by frame.
Question - Does anyone know what software i could use to manipulate the mp4 file frame by frame..maybe something that allows enhancing (like a photoshop for video ? )
some ninja 007 software would be swell right about now but maybe my imagination of such software is getting the better of me.
i tried manipulating the raw video with imovie but surely that is the wrong tool for this job
Would love it is someone with any previous experience could help me. Any suggestions? Thanks!
Sun May 04, 2014 4:08 am
I doubt it's the best and it's definitely not the most current software, but I use Avidemux when I want to capture a single frame or even edit a short clip of almost any video format.
Don't know if it would help in your case. Avidemux can read most formats but not all.
Sun May 04, 2014 11:59 am
To determine frame rate and resolution, load it in VLC and hit Ctrl-J, or go to Tools, Codec Information.
There's nothing that will help you get more information from images like the one you posted. The exposure time was too long for that amount of motion, and the motion blur is pretty extreme.
If you go frame by frame and there aren't any frames of the object moving slowly or stopped with little or no blur, there's not much to be done.
Mon May 05, 2014 7:23 am
Thanks @maxicon and @latropa
no matter what i tried i think the starting resolution is just not good enough to stop a frame clearly.
The best angle frame i got was this
messed with Photoshop to try to decipher the plate but nothing really worked.
The agony of defeat
moving forward, is there any good recommendation for this type of face/license plate recognition?
Hindsight is 20/20 so What type of setup should i have had to be able to catch the important parts (face recognition/targeting and vehicle license plate) of surveillance video?
Mon May 05, 2014 12:23 pm
Plates are tricky to do. You need a good low light sensitive camera to get faster shutter speeds, we use an Axis Q1604. Then you need lighting. Lighting allows you to set a faster shutter speed to stop motion blur, we use a Raytec RM100. Next you need a telephoto lens, for example, we capture plates at about 70-80' away and have our 5-50mm varifocal lens very close to the max 50mm, maybe get away with 20-30mm if it's closer like 30-40' away. We get crystal clear plates day or night.
It's hard to do with a general purpose camera, but say you are on a budget. Get a 12mm IR bullet, like the Hik 2032. Get the camera in a way so it's no more than say 15-20' away from the plate, set the resolution to 3MP and set the max shutter way up to between 1/120 and 1/250 or the highest you can get and be able to read a plate so it's not blown out as a white rectangle and not too dark where you can't read it. Don't worry about anything else as it will all be pitch black except plate and headlight/taillights. I would go for rear plates because a) they are lit, b) many cars where I live don't have front plates, c), tail lights are less bright than headlights, d) front plates are sometimes dirty from bugs and stuff. Also, set image sharpness way down, like 25%, set contrast up a little and turn off smart ir, not so smart. Also turn off BLC or WDR as that will introduce noise.
Mon May 05, 2014 3:08 pm
Yeah, in that pic, the plates are about 25 pixels wide. In California, motorcycle plates are 7" wide, so that's about 43 pixels per foot. In bright light with good resolution and no motion blur, that might be barely enough to read the plate, but at night, with reduced resolution and motion blur, there's no chance. You'd probably need 2-3x the ppf, and a faster shutter speed, as BW describes.
For any decent chance with plates, you'll need a dedicated plate cam, in addition to your general purpose cam that shows what's going on in the overall scene.
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