[HN Gopher] Show HN: OpenScan - open-source document scanner app
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Show HN: OpenScan - open-source document scanner app
Author : mighty3xodus
Score : 137 points
Date : 2021-01-03 14:57 UTC (8 hours ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| jabberwcky wrote:
| Quick take: this is staying on my phone, great effort :)
|
| Notes:
|
| - Doesn't keep flash permanently on (like CamScanner)
|
| - Skew correction looks maybe worse quality (than CamScanner)
|
| - Totally fine for at least 80% of the things I'd use CamScanner
| for. Super well done!
| mighty3xodus wrote:
| Your suggestions are noted. Thank you for your feedback!
| quuuux wrote:
| Looks like a really great start! Just gave the app a quick test
| and the basics seem to be working fine.
|
| Apart from automatic cropping and perspective distortion
| correction others have mentioned already, the white margins of
| the exported PDFs are IMHO quite a bit too large. In fact, as the
| app is a document scanner, I'd not expect any border at all.
| ssheth wrote:
| NAPS2 (https://www.naps2.com/) is also a similar open-source app
| with OCR built in.
| rkagerer wrote:
| What OCR engine does it use and is it any good? (I see
| tesseract mentioned in the dependencies?)
| alexmcc81 wrote:
| I see there is an F-Droid compatible repo linked. Is there a
| reason it has not been submitted to F-Droid proper? Sounds like a
| perfect addition to the default repo.
| mighty3xodus wrote:
| True. Have started the process. Hopefully it builds without
| much problems.
| mawise wrote:
| I don't see anything on the readme about OCR. In the PDF
| conversion, does OpenScan do any OCR? I guess I expect this from
| a document scanning app these days, but I don't really know the
| space. Are there any good open-source OCR libraries?
| bane wrote:
| I would recommend https://github.com/PaddlePaddle/PaddleOCR
| over the default tesseract. It seems to do a better job these
| days and uses more modern approaches.
| pedro2 wrote:
| Tesseract? The page does not refer OCR anywhere, neither does
| it appear on its issues.
| mighty3xodus wrote:
| There are no OCR capabilities. Just managed to get a good
| cropper implemented with perspective cropping. There were very
| few options of which only one was viable.
| BorisEm wrote:
| A related open source library for iOS.
| https://github.com/wetransfer/wescan
| gregod wrote:
| Btw: The Apple Notes application has this functionality built-
| in if you are just interested in scanning.
| twobitshifter wrote:
| And in the files app, long tapping gives the option to scan a
| document, which works great. I'm trying to retain fewer
| pieces of paper and this is super convenient.
| pricci wrote:
| I like that you are using Flutter. Will give a look at the code.
|
| The image quality is not good, but probably due to my camera. CS
| CamScanner gives me better results but I don't trust it.
| adontz wrote:
| User Experience: This app does not open scan dialog immediately,
| annoying.
|
| Features: This app does not fix perspective distortion.
|
| Office Lens
| (https://play.google.com/store/apps/details?id=com.microsoft....)
| is so much better, I get rectangular image without any hints, to
| say nothing about manually selecting anything.
|
| Office Lens really creates this https://play-
| lh.googleusercontent.com/AgErNUVn_Jg41jSQO2p2CF... from this
| https://play-lh.googleusercontent.com/yv6eUY6EyR8x2Hd6NB1SBW...
| and that is amazing.
| solarkraft wrote:
| Office Lens is very good, but huge (> 100MB) and ... pretty
| proprietary and with some UX quirks. I'd greatly appreciate a
| FOSS version of it.
| hawski wrote:
| I always wanted a tool to place a polygon (even just four
| corners) and ability to set an aspect ratio (custom or preset
| like 4:3, 16:9 and A-series) and have perspective fixed image
| or just move vertices around (just like you expect by having a
| textured polygon). I would like to have this tool as a part of
| GIMP and a standard around light image editing tools like many
| viewers are. Perspective correction tools are either designed
| for photography or I don't really know how to use them. When
| you have this you can add edge detection and you're almost done
| to do this automatically.
| deknos wrote:
| is it able to store the document somewhere via a protocol? that
| would be really helpful, perhaps with tags?
| vzaliva wrote:
| It is nice start, but cropping function is pretty much not
| working. When scanning with the phone the page is rarely properly
| alighned ans cropping step should be automatic (like with
| CamScan). Even if performing it manually under perfect conditions
| (white page on back background) it fails to detect page
| boundaries. Screenshot:
| https://www.dropbox.com/s/cpvdidugiy7n3lk/Screenshot_2021010...
| gman83 wrote:
| What are you using for state management besides setState() ?
| mighty3xodus wrote:
| None. Any suggestions? Because most of the state manipulation
| is done in a single screen.
| renewiltord wrote:
| Very cool. I currently use PhotoScan. I'll give this a shot.
| nimbius wrote:
| Question: can it remove printer steganographic tracking dots?
|
| https://en.wikipedia.org/wiki/Printer_steganography
| mighty3xodus wrote:
| I'm not sure that it can...
| gsich wrote:
| If your camera is low-res enough, sure.
| pinusc wrote:
| My first instinct is to compare this to OpenNoteScanner, the only
| other quasi-functioning FOSS note scanning app.
|
| The UI here is significantly more polished and better. The only
| thing OpenNoteScanner does better is that it starts in camera
| mode, and therefore the workflow is a bit faster.
|
| However, feature-wise this is seriously lacking. I would not
| consider using this until it can automatically crop and correct
| perspective distortion.
|
| Also the default filters are seriously lacking. Either make them
| smarter or give the user more control (e.g. for B/W allow setting
| the threshold, even for decently-lit documents I get poor results
| with random black areas)
|
| You can do both by integrating with OpenCV. No idea how easy it
| is to integrate it with flutter though...
|
| Anyways, good job! I'll keep following the project and might
| consider contributing if you ever start working on these
| features.
| mighty3xodus wrote:
| Thank you for the suggestions! I will for sure take it into
| consideration.
|
| The scanner itself is from another open source project, the
| only one which was a viable option. I'll have to look into
| OpenNoteScanner's scanner if I were to improve mine. Seems
| people are happy with the edge detection it offers.
|
| Thank you :)
| sdwolfz wrote:
| I've used OpenNoteScan before:
|
| * https://f-droid.org/en/packages/com.todobom.opennotescanner/
|
| * https://github.com/allgood/OpenNoteScanner
|
| It works OK but it looks a bit old, and you need to install
| OpenCV Manager separately, outside of F-Droid for it to work.
|
| I can deal with it, but there's no way I could ever be able to
| convince anybody else, especially non-tech people to use it.
|
| This one looks like a winner in terms of UX, so I'll be using it
| from now on, Thank you for creating it!
| app4soft wrote:
| > _I 've used OpenNoteScan before:_
|
| Small correction: it is _Open Note Scanner_ app (NOT
| _OpenNoteScan_ )
| mighty3xodus wrote:
| Thank you!
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(page generated 2021-01-03 23:01 UTC)