Do you think this licence plate could be enhanced?

asked 2015-10-19 05:42:36 -0500

Wicio gravatar image

I have just a couple of snapshots of a car. The license plate is unreadable. I tried SuperResolution (on manually extracted and perspective corrected license plates), but it did not help much. Do you think it is possible to enhance these images so that at least something can be read?

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I do not think that this is possible. Your camera is too far, and the quality of image does not help either. Therefore, most likely you are helpless here.

theodore gravatar imagetheodore ( 2015-10-19 09:41:36 -0500 )edit

What is wrong with the car? Is it the speed? Isn't there a color shift?

thdrksdfthmn gravatar imagethdrksdfthmn ( 2015-10-19 09:42:54 -0500 )edit

I think that even if somebody can found an answer. Is it fair to give it on a forum?

LBerger gravatar imageLBerger ( 2015-10-19 12:06:45 -0500 )edit

These are images from a city camera system and this pink coloring appears on every bright surface in strong sunshine :( The images are generally of not bad quality and resolution (1920x1440), but fine details (such as license plate characters) are deteriorated by compression. Another problem is that the frame rate is only 5 fps, so it is impossible to get more images with just minimal variation.

I, too, think that it is not possible to get anything from these photos, but before giving up I thought I better ask some experts :)

Giving an answer or at least some suggestion is more than fair I think. This is not a homework or something....

Wicio gravatar imageWicio ( 2015-10-19 12:47:19 -0500 )edit

PS Giving a license plate it's not fair (Would you like it if it is your car?).

Now about your problem I cannot say that's not possible to read license plate. I need one or two days to try one method.

If without shine you can read license plate have you try to insert a polarised filter in front of your camera?

LBerger gravatar imageLBerger ( 2015-10-19 16:31:37 -0500 )edit

@LBerger you really think that you can acquire such an information from these images? I would be really interested to hear about your approach.

theodore gravatar imagetheodore ( 2015-10-19 17:56:18 -0500 )edit

@theodore No I think it's not possible but I must try before yes or no

LBerger gravatar imageLBerger ( 2015-10-20 02:16:19 -0500 )edit

It is ugly that you have such a big resolution and it compresses it to destroy in fact the details... But I see color shifting (at least blue of the car)

thdrksdfthmn gravatar imagethdrksdfthmn ( 2015-10-20 03:25:38 -0500 )edit

What companies using similar software do is

  • Since the camera is fixed, in position, they know the actual distance to an object
  • Grab a picture of 1 average resolution cam, to grab the car
  • Calibrate a second high resolution cam, to grab only the front end of the car on the complete resolution

Try this maybe?

StevenPuttemans gravatar imageStevenPuttemans ( 2015-10-20 04:52:54 -0500 )edit

@StevenPuttemans so it's a need of 2 cameras?

thdrksdfthmn gravatar imagethdrksdfthmn ( 2015-10-20 05:03:08 -0500 )edit

Thanks for all the comments.

I cannot modify the camera system in any way. It is fixed, it is not mine and I was just asked to try finding a way of getting SOMETHING out of these particular images.

That would be great if someone could come up with something. Even a part of the number will be a success. But it is going to be hard as we even do not know how many characters there are! Most likely the format is XYZ 123?? or XY 123??, where ? stands for any letter on digit

Wicio gravatar imageWicio ( 2015-10-20 05:56:15 -0500 )edit

@StevenPuttemans I have got some results which are not very good. Do you think that I can post it here?

LBerger gravatar imageLBerger ( 2015-10-20 07:16:44 -0500 )edit

@LBerger I think you should. Also I think you should provide some info behind the idea that you used and how you thought that it would help. Because it might not help in this case but for someone else it could be useful ;-)

theodore gravatar imagetheodore ( 2015-10-20 07:42:35 -0500 )edit

Of course you can @LBerger :D go ahead!

StevenPuttemans gravatar imageStevenPuttemans ( 2015-10-21 02:57:47 -0500 )edit

As to @thdrksdfthmn I know of 3 companies who do it this way, but I also know of a system that does it with a single camera. Problem always is, that their codes are closed source, so it is guessing how they are doing it.

StevenPuttemans gravatar imageStevenPuttemans ( 2015-10-21 02:58:40 -0500 )edit

@Wicio there is a reason why most systems are not using RGB cameras for this but NIR cameras. The paint of the license plate has worldwide guidelines to have a high reflectance in the NIR spectrum. It might be that your setup just makes it impossible to read number plates...

StevenPuttemans gravatar imageStevenPuttemans ( 2015-10-21 03:00:17 -0500 )edit

As I said my results are not very goods but you can download here.

LBerger gravatar imageLBerger ( 2015-10-24 07:18:08 -0500 )edit

Thanx a lot. It looks like the number might be 1261, but it's more of a guess. The last digit could as well be the frame. What methods/programs did you use? I got a similar result with SmartDeblur but less sharp. Yours is clearer.

Wicio gravatar imageWicio ( 2015-10-24 09:59:26 -0500 )edit