System Information

OpenCV version: 4.9.0
Operating System / Platform: Windows 64 Bit
Language: Java

Detailed description

Hello there ! I’m working with OpenCV in order to generate QR Codes.
I want to use the function encodeStructuredAppend
If I try with params.structure_number = 3 it generates 3 QR code with all the informations in it but if I use QR Scan Tool, it cannot read correct.

Result:
Scan image 1: QRCode Structure Append: 4 of 3 was found.
Scan image 2: QRCode Structure Append: 3 of 3 was found.
Scan image 3: QRCode Structure Append: 2 of 3 was found.

Steps to reproduce

// java code sample
package test1;

import java.util.ArrayList;
import java.util.List;
import org.opencv.core.Mat;
import org.opencv.core.Size;
import org.opencv.imgcodecs.Imgcodecs;
import org.opencv.imgproc.Imgproc;
import org.opencv.objdetect.QRCodeEncoder;
import org.opencv.objdetect.QRCodeEncoder_Params;

public class opencv_demo {

public static void main(String[] args) {
	
	// TODO Auto-generated method stub
	System.loadLibrary("opencv_java490");
	
	QRCodeEncoder_Params param = new QRCodeEncoder_Params();
	param.set_structure_number(3);
	
	List<Mat> qrcodes = new ArrayList<Mat>();
	
	QRCodeEncoder.create(param).encodeStructuredAppend("Some text to test, more or less big, i tried differents things, 123456", qrcodes);

	for(int i = 0; i < qrcodes.size(); i++) {
		
		Mat qrcode = qrcodes.get(i);
        
		Mat dst = new Mat();
		Size size = new Size(256, 256);
		
		Imgproc.resize(qrcode, dst, size, 0, 0, Imgproc.INTER_AREA);
		Imgcodecs.imwrite("D:\\test\\demo" + String.valueOf(i)+ ".png", dst);
		
	}
}

}

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues, forum.opencv.org, Stack Overflow, etc and have not found any solution
• I updated to the latest OpenCV version and the issue is still there
• There is reproducer code and related data files (videos, images, onnx, etc)