Notices

It's a high-density barcode, and QR codes can be up to about twice this big, according to Wikipedia.

And I don't want to nag or anything, but a colleague's Android 2.2 device (running on HTC's Desire hardware) is scanning the one above without any problem.

Quick reply...
http://commons.wikimedia.org/wiki/File:CodiQR.png
can be read.
The problem is, your code seems to be 6.25 simes larger than the above-mentioned, and with small size of image (400*240) the code is difficult to recognise precisely.
Taking larger image from camera could resolve the problem, maybe.

The reason I've chosen such a low resolution is because higher resolutions affect the performance much more. 400x240 is also the aspect ratio of the screen.

We might avoid this if we don't crop the image (as much) or by increasing the recorded resolution. The former will increase performance, but make it harder to aim, and the latter will decrease performance.

Maybe we could implement this as a user option, as it is a special case?

Ok, I'm planning the following:

Leaving the output image at the current res and add in another scaling element before the screen sink to ensure this always remains the same. Generate higher res frames from the camera and pass them through another scaler so that we can alter the size of the frames being fed to the decoder threads.

That way the UI should remain ok (i.e. no changes necessary and still quick enough), and we will be able to vary the data passed to the decoders from the current low res (i.e. quick scanning) up to something large enough to handle these high density barcodes.

The only slow down then should be from the large volumes of data being passed around, and the additional scaling operation, I hope!

I'll have to test and see whether that produces acceptable performance.

I don't know much (read: nothing) about image processing, but would it be possible to use low-res to detect things that look like barcodes, and only then take a hi-res picture to pass to the decoder? The "look like barcodes" part being the difficult one, of course, but I wonder if an image classifier couldn't do the trick there (I have no idea how computing intensive it would be compared to decoding hi-res pictures).

ever since one or perhaps a few updates ago all the plugins are gone even though they're installed, all i get is the copy button

btw, the automatic portrait mode is borky

(is this the rhread for this?)

Quick reply.
Type
mbarcode
in X Terminal
and read what is says about plugins.

Most QRCode readers that I recall seeing in Japan require the user line it up then click a button, allowing processing from a higher resolution image. I don't know how the Android readers do it, I suspect it may be similar (haven't used any to find out.)

One way to work around this issue could be having it watch for the control points enter the box and change the color of the line (or mark the points) and intercepting the shutter button.

Probably easier said than done. We also use external libs to perform the decoding so this would require more integration, however there's no reason it couldn't be done inside these external libs, it's just a question of whether it's necessary for them, and whether the cost of scaling is less than the cost of trying to decode the whole frame. I don't know.

In the latest update you should get mBarcode installed and it depends on the plugin meta package, which should install all of the plugins. Are you on the latest extras-devel version? If so, I'll have to do some checking for you.

Yeah, portrait mode is no doubt borky, needs some work