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I work on EasyALPR which I’m putting through Startup School. One thing often missed in license plate reading is that the tech is really well solved now using a

I work on EasyALPR which I’m putting through Startup School. One thing often missed in license plate reading is that the tech is really well solved now using an open source stack. There is always room for improvement so I welcome new technological approaches like this. However when thinking about license plate data, the real trouble is in what you do with the data, how you handle duplication, and create rules and interface to make the collection useful.

TuringNYC 7y ago
I'd love to hear about your stack. I tried this with -- Object Detection for Plate localization; -- OpenCV for de-obliqueing angled images -- Character separation from background; -- OCR around individual characters via Convnet Classifier I tried this with decent results, but I wonder what state of the art open-source is?
- m463 7y ago
  probably this? https://github.com/openalpr/openalpr https://github.com/openalpr/openalpr
aidenn0 7y ago
My uncle is a cop in DC and he says >90% of the hits on plates are for the same number but a different state. Is there any work in identifying the state a license plate is from? Just the style is often enough to narrow it down, despite the fact that most license plate frames partially or totally cover up the state name.
- bredren 7y ago
  I’m. It aware if efforts to identify same plate, different state. If the data quality is so good you’re getting exact same plate different states, that is impressive. Instead, I’d look at vehicle type identification. There is at least one startup selling an API that determines make / model info that when combined with license plate you would very likely find unique data.
- thaumasiotes 7y ago
  > My uncle is a cop in DC and he says >90% of the hits on plates are for the same number but a different state. Is there any work in identifying the state a license plate is from? As is so often the case, it seems like it'd be easier to move ourselves to the machine, by including the state information in the code. If a code can only belong to one state, this problem just can't arise.
  - stevewodil 7y ago
    Perhaps each new plate issued should include the state abbreviation in one of the corners (such as CA for California)
    - thaumasiotes 7y ago
      It's possible but not necessary. License plates already feature non-overlap -- a standard California plate is 2AAA222, while a New Mexico plate is AAA222. Neither template can be confused for the other.
      - dragonwriter 7y ago
        > License plates already feature non-overlap No, they don't. > a standard California plate is 2AAA222, while a New Mexico plate is AAA222. And the New Mexico AAA222 pattern is currently shared with Arkansas, Indiana, Iowa, one of the optional Michigan designs, Mississippi, one of the Montana designs, some Nebraska plates, North Carolina, the Northern Mariana Islands, Oklahoma, Puerto Rico, South Carolina, Vermont, and the US Virgin Islands. To be fair, only NC, OK, and PR share NMs use of a dash between the alpha and numeric portion.
        aidenn0 7y ago
        Virginia used to issue in that pattern, with a dash between. Then they ran out and added a 4th digit. However, there are plenty of VA plates still around with the old pattern.
        7y ago
joewee 7y ago
Any improvement in reading plates at a angle? From my experiments it’s very difficult to ready plates from dash cameras of cars in the left and right lane, even though the human eye can identify them.

TuringNYC 7y ago

I'd love to hear about your stack. I tried this with -- Object Detection for Plate localization; -- OpenCV for de-obliqueing angled images -- Character separation from background; -- OCR around individual characters via Convnet Classifier I tried this with decent results, but I wonder what state of the art open-source is?

m463 7y ago
probably this? https://github.com/openalpr/openalpr https://github.com/openalpr/openalpr

aidenn0 7y ago

My uncle is a cop in DC and he says >90% of the hits on plates are for the same number but a different state. Is there any work in identifying the state a license plate is from? Just the style is often enough to narrow it down, despite the fact that most license plate frames partially or totally cover up the state name.

bredren 7y ago
I’m. It aware if efforts to identify same plate, different state. If the data quality is so good you’re getting exact same plate different states, that is impressive. Instead, I’d look at vehicle type identification. There is at least one startup selling an API that determines make / model info that when combined with license plate you would very likely find unique data.
thaumasiotes 7y ago
> My uncle is a cop in DC and he says >90% of the hits on plates are for the same number but a different state. Is there any work in identifying the state a license plate is from? As is so often the case, it seems like it'd be easier to move ourselves to the machine, by including the state information in the code. If a code can only belong to one state, this problem just can't arise.
- stevewodil 7y ago
  Perhaps each new plate issued should include the state abbreviation in one of the corners (such as CA for California)
  - thaumasiotes 7y ago
    It's possible but not necessary. License plates already feature non-overlap -- a standard California plate is 2AAA222, while a New Mexico plate is AAA222. Neither template can be confused for the other.
    - dragonwriter 7y ago
      > License plates already feature non-overlap No, they don't. > a standard California plate is 2AAA222, while a New Mexico plate is AAA222. And the New Mexico AAA222 pattern is currently shared with Arkansas, Indiana, Iowa, one of the optional Michigan designs, Mississippi, one of the Montana designs, some Nebraska plates, North Carolina, the Northern Mariana Islands, Oklahoma, Puerto Rico, South Carolina, Vermont, and the US Virgin Islands. To be fair, only NC, OK, and PR share NMs use of a dash between the alpha and numeric portion.
      - aidenn0 7y ago
        Virginia used to issue in that pattern, with a dash between. Then they ran out and added a 4th digit. However, there are plenty of VA plates still around with the old pattern.
      - 7y ago

joewee 7y ago

Any improvement in reading plates at a angle? From my experiments it’s very difficult to ready plates from dash cameras of cars in the left and right lane, even though the human eye can identify them.