Orientation corners of a QR-code

Question

As of now, when Android Vision detects a QR-code, the array "Barcode.cornerPoints" (which contains the code's corner points) is populated in a seemingly random order. I need is to determine which 3 out of the 4 corner points that contains "orientation squares".

The current approach I am using is very unsatisfying:

1. For every detected QR-code, I am forced to create a bitmap and attempt to find the QR-code again with another library (Zxing) that always returns the corner points in a consistent order with respect to rotation.

2. If Zxing finds the QR-code (which sadly doesn't happen about four times out of five), I need to cross-check and match the Zxing-corners with Android Vision corners.

What I would like is to get the array "Barcode.cornerPoints" populated with respect to orientation.

For example and clarification:

cornerPoints[0] = //First corner-point with an orientation square
cornerPoints[1] = //Second corner-point with an orientation square
cornerPoints[2] = //Third corner-point with an orientation square
cornerPoints[3] = //The corner-point that does not contain a orientation square

> Like in this picture <

I have been trying to find a clever workaround to this issue for quire a while now but I can't come up with any good solution, and it does not appear as Google has open source'd the code used when population the qrCorners array so i can't extend it...

Any help out there? I am not the only one who has been looking for a solution to this issue:

https://github.com/googlesamples/android-vision/issues/103

Answer 1

I am in a similar situation as well. What might help you to know is that Android Vision does not return the corner points in a completely random order.

I believe that the detector scans the image from top left to bottom right of the frame. The QR-code-corner which is detected first in the image will be returned as corner 0 and the rest in a clockwise direction.

What would be really helpful was if Android Vision returned the corners like you said, in a "static" order depending on orientation. I barely see any reason for the chosen way to return the corner points. Maybe better performance? For the QR-code to be read it has to be done according to a certain orientation which is determined by the corners of the QR-code. Which means Android Vision already has identified the orientation and corners but does not give this information to us. Maybe this could be added in future updates?