[OSM-talk] Pictures of opening hours signs for machine learning purposes
iboates at gmail.com
Sat Apr 10 19:40:10 UTC 2021
I took the images from the "deduplicated in Bryce's download link and ran
them through Amazon Rekognition for text extraction. So no actual training
or modelling done by me, but it's a pretty cheap service (1.20 USD per 1000
images on the Frankfurt server). It gives back a JSON for every image with
precise details about what it found, where it is on the image, etc. So I
saved the results for each image with a JSON with the same name as the
image, just with ".json" as a file extension.
I didn't go through the results in detail just yet, I wanted to share them
first so anyone can dig through them to see what's in there & potentially
get ideas from them. One thing I did notice however is that it does not
detect accented characters, so "Öffnungszeiten" becomes "Offnungszeiten".
It will probably then have trouble detecting the "ß" character if it comes
up (will probably often show up as "B", but from what I understand it
doesn't appear in Swiss German.
The data is not big but not tiny either (about 23MB) I've put them into a
Also just as a disclaimer I am not affiliated with Amazon in any way, I
just had some experience with this specific product from them and thought
it would be good to just run the data through a "state of the art"
pre-built ML solution.
On Sat, Apr 10, 2021 at 4:04 PM Isaac Boates <iboates at gmail.com> wrote:
> @Lukas: I was having a bit of trouble getting the guest account
> permissions set up on my AWS but then Bryce went ahead and posted a direct
> link, thanks for that!
> On Sat, Apr 10, 2021 at 5:52 AM Bryce Cogswell via talk <
> talk at openstreetmap.org> wrote:
>> @Bryce: Did you already make significant efforts regarding deduplicating
>> / sorting or otherwise processing the images? If yes, maybe you could share
>> this altered dataset with Isaac and other interested parties?
>> I didn’t do any additional work on deduplicating the images. I’m not sure
>> why you think this is important if you’re going to use it for ML training.
>> @Bryce: Congratulations! I already saw some correctly recognized
>> specimens! That is certainly encouraging, isn't it? Do you already know
>> if/how you would proceed further? If you would be okay with publishing with
>> what you already have, maybe others could build upon that.
>> I remember one idea we had: If users of such a recognition feature would
>> be willing to (automatically, with little/no effort) share the pictures to
>> increase the pool of pictures you could create a virtuos cycle, especially
>> if you can motivate them to either mark detections as correct or let them
>> fix it as needed.
>> Keep in mind I’m not doing any ML training, so having a larger sample
>> size doesn’t benefit me. I wanted a large number of test images in order to
>> measure the expected accuracy of the OCR and algorithm in a real-world
>> settings. My plan now is to build a stand-alone app for testing during
>> surveying, improve the recognition by building better spatial models of how
>> the text is laid out, and then finally integrate it into Go Map!!
>> I’m working on this at https://github.com/bryceco/OpeningHoursPhoto but
>> the code is super rough at this point.
>> The image set it is at
>> <http://gomaposm.com/opening_hours/opening_hours.zip> (12.5GB download)
>> talk mailing list
>> talk at openstreetmap.org
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