QR Code Encoder: Timing pattern is broken if version >= 7. #22029
Description
System information (version)
- OpenCV => 3.4
- Operating System / Platform => ubuntu 22.04
- Compiler => gcc11
Detailed description
A part of timing Pattern is broken. (Same as left-bottom parts).
Timing pattern is used to determine version. So QRCodeDetector cannot decode it.
Left image is expected output. Right image is current output.
Reason
Version information and timing pattern is overlapped when ( i== 6 or j == 6).
https://github.com/opencv/opencv/blob/3.4/modules/objdetect/src/qrcode_encoder.cpp#L976
if (version_level >= 7)
{
for (int i = 0; i <= 6; i++) // (1) Version information
{
for (int j = version_size - 11; j <= version_size - 8; j++)
{
original.at<uint8_t>(i, j) = INVALID_REGION_VALUE;
original.at<uint8_t>(j, i) = INVALID_REGION_VALUE;
}
}
}
for (int i = 0; i < version_size; i++) // (2) Timing pattern
{
for (int j = 0; j < version_size; j++)
{
if (original.at<uint8_t>(i, j) == INVALID_REGION_VALUE)
{
continue;
}
if ((i == 6 || j == 6))
{
original.at<uint8_t>(i, j) = INVALID_REGION_VALUE;
if (!((i == 6) && (j - 7) % 2 == 0) &&
!((j == 6) && ((i - 7) % 2 == 0)))
{
masked_data.at<uint8_t>(i, j) = 0;
}
}Steps to reproduce
expect_msg = "OpenCV";
Mat qrimg;
QRCodeEncoder::Params params;
params.version = 7;
Ptr<QRCodeEncoder> qrcode_enc = cv::QRCodeEncoder::create(params);
qrcode_enc->encode(expect_msg, qrimg);
cv::imwrite("qrimg.png", qrimg);How to fix
I feel changing the version information area is better.
- for (int i = 0; i <= 6; i++)
+ for (int i = 0; i <= 5; i++)
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