I'm interest in extracting barcode image. And I'm using ZXing C++ Port from https://github.com/glassechidna/zxing-cpp.
But when I build with cmake and run with all barcodes which ZXing support, only 8/15 barcodes can be decoded, including:
Code 39, Code 93, Code 128, ITF, Codabar, Aztec, UPC-A and UPC-E
The remaining barcodes: QR Code, Data Matrix, PDF 417, EAN-8, EAN-13, RSS-14 and RSS Expanded can't be decoded.
And I don't know why, while with the same barcodes, I test in ZXing home page (online) from: http://zxing.org/w/decode.jspx, all barcodes are decoded normally.
Anyone has been met as same as me? Or if you know why, please help me!
Anyone looking for an up-to-date c++ port of ZXing, you might want to give https://github.com/nu-book/zxing-cpp a try. It can decode all the mentioned codes and do that more reliably and faster than the original Java upstream project.
Related
Running the latest java version produces "no barcode found" on an image.
java -cp core-3.4.0.jar:javase-3.4.0.jar:jcommander-1.72.jar:jai-imageio-core-1.4.0.jar com.google.zxing.client.j2se.CommandLineRunner --try_harder ./IMG.jpg
file:///home/tom/Projects/mTicketing/zxing_java/./IMG.jpg: No barcode found
However, using the web site https://zxing.org/w/decode and the same image produces:
eyJ2ZXJzaW9uIjoidGZpLjEiLCJhbGciOiJSUzI1NiIsImFjdCI6IjIwMjAtMDQtMjhUMDc6NTc6NDYrMDE6MDAifQ==.eyJkdXIiOiJQVDkwTSIsIm9wIjoiQnVzIEVpcmVhbm4iLCJwciI6IlNpbmdsZSBKb3VybmV5IFRpY2tldCBBZHVsdCIsImZyb20iOiJDbGFyZWNhc3RsZSIsInRvIjoiU2hhbm5vbiBJbmR1c3RyaWFsIEVzdC4iLCJybiI6IjExMjE5IiwiYW4iOiJUb20gQnlybmUiLCJ1dG4iOiI2OTE2NDQzOC02M2RkLTRhY2YtOGZlNS01MjUyMjZmYjhmOTcifQ.Aw_3tELIvR6EqatwR-QxwXC5V1F7Cznr0FfZkl8O8SIYzwcOyJ_coCqBs_2UKMghv0WVNAXikHmavMqLLEaug2H41ElFs48lBz8yEgsCsrbeau2AWDd14KixsfITx3rps9HqMf-aPxb5B3Dw6vYFh2Gnokb1Dhbqfhb1a5j5UJI
However, if the base64 padding is removed from the header in the JWT token ('==') and a QR code generated, the barcode is decoded successfully by both the site and the java code.
I know Base64Url should be used but why is the image successfully decoded by the zxing site and not by the latest jar files?
And why would padding produce an image that is hard to decode?
So, after some more research, I'm pretty sure that the issue I noticed was associated with the length of the data encoded and the resolution of the device displaying the Aztec code and nothing to do with the padding.
As the length of encoded data increases in size, the visual complexity of the Aztec QR code increases. I found that if I used a lower resolution device or deliberately set the screen resolution of a device to low, more complex codes were not reliably decoded.
There was some differences between the ZXING site and the java code but I suspect the site may have a set of decode hints pre-configured.
Is it possible to scan multiple qr codes from a single image ? If so how can I implement it ? I have a requirement to scan all qr codes from the single image..
In the svn trunk, there's support for multiple QR codes in QRCodeMultiReader. Not sure what you're using on the iPad but (the widget or the objc library) but it should be pretty easy to tie the QRCodeMultiReader in to those.
The Java version of zxing, which is the main version, contains support for reading multiple barcodes in one image. Look at MultipleBarcodeReader. You'd have to port it, but, it's not that hard.
I am developing App in which PDF text searching & highlighting is needed. I found like its very difficult to highlight in PDF. So i thought to convert PDF to HTML then by using java-script, Search the string & Highlight it. Actually i got success in searching & highlighting on HTML text using java script.If any1 need source code send your email id.
But my obstacle is PDF to HTML conversion. I know it is very hard,bcoz PDF is enrich text & HTML doesn't support all the features. In between i got some source code in Python i.e. PDFMiner. With out jail breaking its hard to use Python in IOS. So i dropped this idea also.
Now i m looking on xPDF, its C++ based code to convert PDF to HTML. Did any1 got success over integrating xPDF into your IOS app. I want to know feasibility of this.
Thanks in advance for ur thoughtful reply,
Naveen Thunga.
Here you can find an example. Still has some problems, but is a good start:
https://github.com/KurtCode/PDFKitten
I am looking to encode a jpg sequence into an mpeg format on an iphone project I am working on. My google searches are coming up pretty short. Does anyone happen to know of a library that would let me do something like this?
have a look at ffmpeg
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Hope You all are fine and also in one of your best of moods!!
Hope You all are Enjoying iPhone development.
I herewith one issue that i am not able to solve, may be i don't know the depth concept of iPhone.
So Its my humble requet to you to guide me or suggest or share your ideas.
I do find an issue with getting an image from Bytes array.
I am calling a webservice which returns an image in form of Bytes Array as response.
I have Converted this bytes array in to form of NSData, Now i have NSData, But When i Try to get an image from this NSData, It shows nil.
I Did lots of R&D and Find one suggestion to use base64 encoder, But unfortunately because of not proper guidance I was not able to Implement that.
I was also suggested to use OPenSSL Library for base64 from url http://www.cocoadev.com/index.pl?BaseSixtyFour
But again i was not able to include #include #include these two files. as in Newer Version of SDK 3.X family Apple has depreciated those (as i guess).
So Now i need help from you guys. kindly help me if you have solution or if you know the steps to solve these.
Looking Forwards.
Regards,
Arun Thakkar
Using OpenSSL on the iPhone seems like a very heavy-weight solution if all you need is Base64 encoding/decoding. Look at this post for how to use a category for NSData to add base64 encoding/decoding. You want the second section of this blog post as the first deals with OpenSSL :)
base64-encoding-options-on-mac-and-iphone