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I built a DIY license plate reader with a Raspberry Pi and machine learning

towardsdatascience.com

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Re: I built a DIY license plate reader with a Raspberry Pi and machine learning

#71

Post by paganel »

Piskvorrr wrote: post #64
0x0aff374668 wrote: post #43

Earlier quoted context omitted.

The reason for the negativity is that this demonstrates the "Design by StackOverflow" mentality where the solution is like swatting a fly with a sledgehammer and no real domain knowledge. Plus the author didn't even train the neural nets: it's just a LEGO project. I'd higher this person to be a lab intern, but nothing above that. The fact the author couldn't solve it locally and had to invoke the CLOUD is... laughabl…

TL;DR: reinventing wheels is a good way to learn a lot. For trying out something in a few hours, of course you don't want to spend hundreds of hours setting it up, by definition. Yes, the result is "just about works, but doesn't scale" - but that's the point of experimenting . Sure, this is a LEGO-style experiment in reinventing the wheel, but exactly for that, an excellent way to start learning about this problem do…

> Sure, this is a LEGO-style experiment in reinventing the wheel

If I'm not mistaken Larry Page used to be praised some time ago for building a printer out of LEGO pieces (that may just be an urban legend, I admit I never verified this information).

Re: I built a DIY license plate reader with a Raspberry Pi and machine learning

#72

Post by darkarmani »

simon_000666 wrote: post #44

Ok, I have a use case for this. If you could figure out how to get it off the cloud and low power, it would be awesome to have one of these on the gates to my house, so when I drive up the plates are automatically recognized and the gates open to my car.

Better to use the tire pressure sensors and a software defined radio module to pick up the unique identifiers of your wheels. Way lower power than OCR.

Re: I built a DIY license plate reader with a Raspberry Pi and machine learning

#74

Post by heavenlyblue »

beagle3 wrote: post #38
jlarocco wrote: post #13

"Machine Learning" is the wrong tool for the job here. Tesseract OCR can do this, using only the Raspberry Pi, at a "good enough" framerate for any real driving situation.

Tesseract only does well if the input is clean, aligned, two tone image, already cut down -- but LPR images you get from a moving camera are anything but. Machine learning is a fine tool for this job. The specific machine learning setup is an overkill, though.

Most of these problems are much easier to solve by simply picking a better camera. Moreover license plates are specifically made to be easier to read (ie reflective).

Re: I built a DIY license plate reader with a Raspberry Pi and machine learning

#76

Post by beagle3 »

heavenlyblue wrote: post #74
beagle3 wrote: post #38

Earlier quoted context omitted.

Tesseract only does well if the input is clean, aligned, two tone image, already cut down -- but LPR images you get from a moving camera are anything but. Machine learning is a fine tool for this job. The specific machine learning setup is an overkill, though.

Most of these problems are much easier to solve by simply picking a better camera. Moreover license plates are specifically made to be easier to read (ie reflective).

No they are not. Converting a semi-shaded black-on-yellow to clean black-and-white is not a matter of picking a better camera. Aligning it into am axis aligned rectangle form (from whatever angle you managed to capture them) is not a matter of picking a better camera. Tesseract is really bad unless your input is really clean.

Reflective helps you only if you actually shine light from the direction of the camera. which you can't practically do from within a car (the setup described in the post), and in most jurisdictions cannot legally do at all.

Re: I built a DIY license plate reader with a Raspberry Pi and machine learning

#77

Post by [deleted] »

omneity wrote: post #67
sgt wrote: post #36

Earlier quoted context omitted.

Would be great if we could have built-in Outline support on HN, or some kind of bot commenting a link automatically when someone posts a story with a paywall. Just throwing an idea out there. :)

That's a great idea actually! @dang are such bots allowed in HN? I can roll it out pretty easily with Monitoro ( https://monitoro.xyz ) and would be happy to cover the costs.

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