about QZXingLive + iOS about qzxing HOT 8 CLOSED

Same problem for me. I'm trying to have an app that reads qrcodes on android and ios.
I've tested QZXingLive on Windows 7 and Android and they both work well (with the only problem that in Android the image processing seems to be slow and the camera view every "certain" seconds freezes for a while).
On iOS (iphone 5c) the app starts correctly and the image processing seems to be smooth, but unfortunately it can only recognize barcodes, qrcodes are not recognized.
Could it be a problem with the camera image resolution (maybe too high)?
Please help, otherwise I will have to choose another library :-(

from qzxing.

Hello @rigoryan @mrAlmond

indeed i have never tried the library on iOS due to my lack of iOS device. I only had reports of its functionality by people that have already used it.

I believe that i can acquire an iPhone 7 for the next few days so i will test it and get back to you.

Best regards

from qzxing.

That would be great. Thank you.

from qzxing.

Thanks too.
I just ran tests on my galaxy S4, and works smoothly.

J

from qzxing.

After some tests with the iPhone i saw that the image was flipped and rotated. To commit it properly i need to do some tests and further optimizations.

Though, if you need a quick fix for you to continue your development, you can apply the following change:

diff --git a/src/QZXingFilter.cpp b/src/QZXingFilter.cpp
index f37100b..3b89613 100644
--- a/src/QZXingFilter.cpp
+++ b/src/QZXingFilter.cpp
@@ -158,7 +159,7 @@ static QImage rgbDataToGrayscale(const uchar* data, const CaptureRect& captureRe
     uchar* pixelInit = image.bits();
     data += (captureRect.startY * captureRect.sourceWidth + captureRect.startX) * stride;
     for (int y = 1; y <= captureRect.targetHeight; ++y) {
-        uchar* pixel = pixelInit + (captureRect.targetHeight - y) * captureRect.targetWidth;
+        uchar* pixel = pixelInit + y * captureRect.targetWidth;
         for (int x = 0; x < captureRect.targetWidth; ++x) {
             uchar r = data[red];
             uchar g = data[green];

It would be great if you could give it a try and share your results.

from qzxing.

Again, thanks for quick response and great project.
I confirm the patch works on my iphone 7+ now.

So far, both my galaxy s4 and iphone 7+ work great in daytime when QRCode is shown on my computer screen. I am using a MACBOOK retina screen.

The detection rate dropped when I tried on some product package qrcodes at home in house light condition.

I am wondering whether there are some recommendations on capturing video frames from QML?
E.g. Videofrom/image pre-processing etc.

Just for record, I am using the following QR test code.
https://www.printbusinesscards.com/marketing/qrcode/QR-Code-Quality-Standards-Test.php

from qzxing.

Hi thank you for the fast answer. Today I'm going to do some tests with my iphone 5 and I will let you know ASAP.

from qzxing.

Yes it works! Thank you!

from qzxing.