From 14b5933e8c51abd50a11b545a8808b07ee51f0eb Mon Sep 17 00:00:00 2001
From: sitong lian <563052165@qq.com>
Date: Tue, 6 Sep 2022 23:58:19 +0800
Subject: [PATCH 1/7] fix the bug that cannot detect multi qrcode when
 use_nn_detector is false

---
 .vscode/settings.json                         |  6 ++
 .../samples/qrcode_example_without_nn.cpp     | 67 +++++++++++++++++++
 .../samples/qrcode_without_nn.py              | 50 ++++++++++++++
 modules/wechat_qrcode/src/decodermgr.cpp      | 36 +++++-----
 modules/wechat_qrcode/src/decodermgr.hpp      |  6 +-
 modules/wechat_qrcode/src/wechat_qrcode.cpp   | 26 +++----
 .../src/zxing/qrcode/qrcode_reader.cpp        | 37 +++++-----
 .../src/zxing/qrcode/qrcode_reader.hpp        |  6 +-
 modules/wechat_qrcode/src/zxing/reader.cpp    |  2 +-
 modules/wechat_qrcode/src/zxing/reader.hpp    |  4 +-
 10 files changed, 186 insertions(+), 54 deletions(-)
 create mode 100644 .vscode/settings.json
 create mode 100644 modules/wechat_qrcode/samples/qrcode_example_without_nn.cpp
 create mode 100644 modules/wechat_qrcode/samples/qrcode_without_nn.py

diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 000000000..553817fbf
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,6 @@
+{
+    "cquery.cacheDirectory": "${workspaceFolder}/.vscode/cquery_cached_index/",
+    "files.associations": {
+        "vector": "cpp"
+    }
+}
\ No newline at end of file
diff --git a/modules/wechat_qrcode/samples/qrcode_example_without_nn.cpp b/modules/wechat_qrcode/samples/qrcode_example_without_nn.cpp
new file mode 100644
index 000000000..7428d0dd6
--- /dev/null
+++ b/modules/wechat_qrcode/samples/qrcode_example_without_nn.cpp
@@ -0,0 +1,67 @@
+#include <iostream>
+#include <opencv2/core.hpp>
+#include <opencv2/highgui.hpp>
+#include <opencv2/imgproc.hpp>
+
+using namespace std;
+using namespace cv;
+
+#include <opencv2/wechat_qrcode.hpp>
+
+int main(int argc, char* argv[]) {
+    cout << endl << argv[0] << endl << endl;
+    cout << "A demo program of WeChat QRCode Detector: " << endl;
+
+    Mat img;
+    int camIdx = -1;
+    if (argc > 1) {
+        bool live = strcmp(argv[1], "-camera") == 0;
+        if (live) {
+            camIdx = argc > 2 ? atoi(argv[2]) : 0;
+        } else {
+            img = imread(argv[1]);
+        }
+    } else {
+        cout << "    Usage: " << argv[0] << " <input_image>" << endl;
+        return 0;
+    }
+    // The model is downloaded to ${CMAKE_BINARY_DIR}/downloads/wechat_qrcode if cmake runs without warnings,
+    // otherwise you can download them from https://github.com/WeChatCV/opencv_3rdparty/tree/wechat_qrcode.
+    Ptr<wechat_qrcode::WeChatQRCode> detector;
+
+    try {
+        detector = makePtr<wechat_qrcode::WeChatQRCode>("", "", "", "");
+    } catch (const std::exception& e) {
+        cout <<
+            "\n---------------------------------------------------------------\n"
+            "Failed to initialize WeChatQRCode.\n"
+            "---------------------------------------------------------------\n";
+        cout << e.what() << endl;
+        return 0;
+    }
+    string prevstr = "";
+    vector<Mat> points;
+
+    if (camIdx < 0) {
+        auto res = detector->detectAndDecode(img, points);
+        for (const auto& t : res) cout << t << endl;
+    } else {
+        VideoCapture cap(camIdx);
+        for(;;) {
+            cap >> img;
+            if (img.empty())
+                break;
+            auto res = detector->detectAndDecode(img, points);
+            for (const auto& t : res) {
+                if (t != prevstr)
+                    cout << t << endl;
+            }
+            if (!res.empty())
+                prevstr = res.back();
+            imshow("image", img);
+            if (waitKey(30) >= 0)
+                break;
+        }
+    }
+    return 0;
+}
\ No newline at end of file
diff --git a/modules/wechat_qrcode/samples/qrcode_without_nn.py b/modules/wechat_qrcode/samples/qrcode_without_nn.py
new file mode 100644
index 000000000..9b8feb520
--- /dev/null
+++ b/modules/wechat_qrcode/samples/qrcode_without_nn.py
@@ -0,0 +1,50 @@
+import cv2
+import sys
+
+print(sys.argv[0])
+print('A demo program of WeChat QRCode Detector:')
+camIdx = -1
+if len(sys.argv) > 1:
+    if sys.argv[1] == "-camera":
+        camIdx = int(sys.argv[2]) if len(sys.argv)>2 else 0
+    img = cv2.imread(sys.argv[1])
+else:
+    print("    Usage: " + sys.argv[0] + "  <input_image>")
+    exit(0)
+
+# For python API generator, it follows the template: {module_name}_{class_name},
+# so it is a little weird.
+# The model is downloaded to ${CMAKE_BINARY_DIR}/downloads/wechat_qrcode if cmake runs without warnings,
+# otherwise you can download them from https://github.com/WeChatCV/opencv_3rdparty/tree/wechat_qrcode.
+try:
+    detector = cv2.wechat_qrcode_WeChatQRCode(
+        "", "", "", "")
+except:
+    print("---------------------------------------------------------------")
+    print("Failed to initialize WeChatQRCode.")
+    print("---------------------------------------------------------------")
+    exit(0)
+
+prevstr = ""
+
+if camIdx < 0:
+    res, points = detector.detectAndDecode(img)
+    print(res,points)
+else:
+    cap = cv2.VideoCapture(camIdx)
+    while True:
+        res, img = cap.read()
+        if img is None:
+            break
+        res, points = detector.detectAndDecode(img)
+        for t in res:
+            if t != prevstr:
+                print(t)
+        if res:
+            prevstr = res[-1]
+        cv2.imshow("image", img)
+        if cv2.waitKey(30) >= 0:
+            break
+    # When everything done, release the capture
+    cap.release()
+    cv2.destroyAllWindows()
diff --git a/modules/wechat_qrcode/src/decodermgr.cpp b/modules/wechat_qrcode/src/decodermgr.cpp
index d4b8edf6f..47a9ec775 100644
--- a/modules/wechat_qrcode/src/decodermgr.cpp
+++ b/modules/wechat_qrcode/src/decodermgr.cpp
@@ -18,7 +18,7 @@ using zxing::Result;
 using zxing::UnicomBlock;
 namespace cv {
 namespace wechat_qrcode {
-int DecoderMgr::decodeImage(cv::Mat src, bool use_nn_detector, string& result, vector<Point2f>& points) {
+int DecoderMgr::decodeImage(cv::Mat src, bool use_nn_detector, vector<string>& results, vector<vector<Point2f>>& zxing_points) {
     int width = src.cols;
     int height = src.rows;
     if (width <= 20 || height <= 20)
@@ -28,7 +28,7 @@ int DecoderMgr::decodeImage(cv::Mat src, bool use_nn_detector, string& result, v
     zxing::ArrayRef<uint8_t> scaled_img_zx =
         zxing::ArrayRef<uint8_t>(new zxing::Array<uint8_t>(scaled_img_data));
 
-    zxing::Ref<zxing::Result> zx_result;
+    vector<zxing::Ref<zxing::Result>> zx_results;
 
     decode_hints_.setUseNNDetector(use_nn_detector);
 
@@ -43,16 +43,20 @@ int DecoderMgr::decodeImage(cv::Mat src, bool use_nn_detector, string& result, v
         } else {
             source->reset(scaled_img_zx.data(), width, height);
         }
-        int ret = TryDecode(source, zx_result);
+        int ret = TryDecode(source, zx_results);
         if (!ret) {
-            result = zx_result->getText()->getText();
-            auto result_points = zx_result->getResultPoints();
-            for(int i = 0; i < result_points->size() / 4; i++) {
-                const int ind = i * 4;
-                for (int j = 1; j < 4; j++)
-                    points.emplace_back(result_points[ind+j]->getX(), result_points[ind+j]->getY());
-
-               points.emplace_back(result_points[ind]->getX(), result_points[ind]->getY());
+            for(unsigned int i=0; i<zx_results.size(); i++){
+                results.emplace_back(zx_result->getText()->getText());
+                vector<Point2f> tmp_qr_points;
+                auto tmp_zx_points = zx_results[i]->getResultPoints();
+                for(int i = 0; i < tmp_zx_points->size() / 4; i++) {
+                    const int ind = i * 4;
+                    for (int j = 1; j < 4; j++){
+                        tmp_qr_points.emplace_back(tmp_zx_points[ind+j]->getX(), tmp_zx_points[ind+j]->getY());
+                    }
+                    tmp_qr_points.emplace_back(tmp_zx_points[ind]->getX(), tmp_zx_points[ind]->getY());
+                }
+                zxing_points.push_back(tmp_qr_points);
             }
             return ret;
         }
@@ -62,7 +66,7 @@ int DecoderMgr::decodeImage(cv::Mat src, bool use_nn_detector, string& result, v
     return -1;
 }
 
-int DecoderMgr::TryDecode(Ref<LuminanceSource> source, Ref<Result>& result) {
+int DecoderMgr::TryDecode(Ref<LuminanceSource> source, vector<Ref<Result>>& results) {
     int res = -1;
     string cell_result;
 
@@ -71,17 +75,17 @@ int DecoderMgr::TryDecode(Ref<LuminanceSource> source, Ref<Result>& result) {
     zxing::Ref<zxing::BinaryBitmap> binary_bitmap(new BinaryBitmap(binarizer));
     binary_bitmap->m_poUnicomBlock = qbarUicomBlock_;
 
-    result = Decode(binary_bitmap, decode_hints_);
-    res = (result == NULL) ? 1 : 0;
+    results = Decode(binary_bitmap, decode_hints_);
+    res = (results.size() == 0) ? 1 : 0;
 
     if (res == 0) {
-        result->setBinaryMethod(int(binarizer_mgr_.GetCurBinarizer()));
+        results[0]->setBinaryMethod(int(binarizer_mgr_.GetCurBinarizer()));
     }
 
     return res;
 }
 
-Ref<Result> DecoderMgr::Decode(Ref<BinaryBitmap> image, DecodeHints hints) {
+vector<Ref<Result>> DecoderMgr::Decode(Ref<BinaryBitmap> image, DecodeHints hints) {
     return reader_->decode(image, hints);
 }
 }  // namespace wechat_qrcode
diff --git a/modules/wechat_qrcode/src/decodermgr.hpp b/modules/wechat_qrcode/src/decodermgr.hpp
index c2f29dbe2..1e04203b2 100644
--- a/modules/wechat_qrcode/src/decodermgr.hpp
+++ b/modules/wechat_qrcode/src/decodermgr.hpp
@@ -26,7 +26,7 @@ public:
     DecoderMgr() { reader_ = new zxing::qrcode::QRCodeReader(); };
     ~DecoderMgr(){};
 
-    int decodeImage(cv::Mat src, bool use_nn_detector, string& result, vector<Point2f>& points);
+    int decodeImage(cv::Mat src, bool use_nn_detector, vector<string>& result, vector<vector<Point2f>>& zxing_points);
 
 private:
     zxing::Ref<zxing::UnicomBlock> qbarUicomBlock_;
@@ -35,10 +35,10 @@ private:
     zxing::Ref<zxing::qrcode::QRCodeReader> reader_;
     BinarizerMgr binarizer_mgr_;
 
-    zxing::Ref<zxing::Result> Decode(zxing::Ref<zxing::BinaryBitmap> image,
+    vector<zxing::Ref<zxing::Result>> Decode(zxing::Ref<zxing::BinaryBitmap> image,
                                      zxing::DecodeHints hints);
 
-    int TryDecode(zxing::Ref<zxing::LuminanceSource> source, zxing::Ref<zxing::Result>& result);
+    int TryDecode(zxing::Ref<zxing::LuminanceSource> source, vector<zxing::Ref<zxing::Result>>& result);
 };
 
 }  // namespace wechat_qrcode
diff --git a/modules/wechat_qrcode/src/wechat_qrcode.cpp b/modules/wechat_qrcode/src/wechat_qrcode.cpp
index 3836ea467..596a72269 100644
--- a/modules/wechat_qrcode/src/wechat_qrcode.cpp
+++ b/modules/wechat_qrcode/src/wechat_qrcode.cpp
@@ -144,21 +144,23 @@ vector<string> WeChatQRCode::Impl::decode(const Mat& img, vector<Mat>& candidate
                 super_resolution_model_->processImageScale(cropped_img, cur_scale, use_nn_sr_);
             string result;
             DecoderMgr decodemgr;
-            vector<Point2f> points_qr;
-            auto ret = decodemgr.decodeImage(scaled_img, use_nn_detector_, result, points_qr);
+            vector<vector<Point2f>> zxing_points;
+            auto ret = decodemgr.decodeImage(scaled_img, use_nn_detector_, decode_results, zxing_points);
             if (ret == 0) {
-                for (auto&& pt: points_qr) {
-                    pt /= cur_scale;
-                }
+                for(unsigned int i=0; i<zxing_points.size(); ++i){
+                    vector<Point2f> points_qr = zxing_points[i];
+                    for (auto&& pt: points_qr) {
+                        pt /= cur_scale;
+                    }
 
-                if (use_nn_detector_)
-                    points_qr = aligner.warpBack(points_qr);
-                for (int i = 0; i < 4; ++i) {
-                    point.at<float>(i, 0) = points_qr[i].x;
-                    point.at<float>(i, 1) = points_qr[i].y;
+                    if (use_nn_detector_)
+                        points_qr = aligner.warpBack(points_qr);
+                    for (int j = 0; j < 4; ++j) {
+                        point.at<float>(j, 0) = points_qr[j].x;
+                        point.at<float>(j, 1) = points_qr[j].y;
+                    }
+                    points.push_back(point);
                 }
-                decode_results.push_back(result);
-                points.push_back(point);
                 break;
             }
         }
diff --git a/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.cpp b/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.cpp
index 64a6c08c9..c5b526263 100644
--- a/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.cpp
+++ b/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.cpp
@@ -34,33 +34,33 @@ QRCodeReader::QRCodeReader() : decoder_() {
     smoothMaxMultiple_ = 40;
 }
 
-Ref<Result> QRCodeReader::decode(Ref<BinaryBitmap> image) { return decode(image, DecodeHints()); }
+vector<Ref<Result>> QRCodeReader::decode(Ref<BinaryBitmap> image) { return decode(image, DecodeHints()); }
 
-Ref<Result> QRCodeReader::decode(Ref<BinaryBitmap> image, DecodeHints hints) {
+vector<Ref<Result>> QRCodeReader::decode(Ref<BinaryBitmap> image, DecodeHints hints) {
     // Binarize image using the Histogram Binarized method and be binarized
     ErrorHandler err_handler;
+    vector<Ref<Result>> result_list;
     Ref<BitMatrix> imageBitMatrix = image->getBlackMatrix(err_handler);
-    if (err_handler.ErrCode() || imageBitMatrix == NULL) return Ref<Result>();
+    if (err_handler.ErrCode() || imageBitMatrix == NULL) return result_list;
 
-    Ref<Result> rst = decodeMore(image, imageBitMatrix, hints, err_handler);
-    if (err_handler.ErrCode() || rst == NULL) {
+    vector<Ref<Result>> rst = decodeMore(image, imageBitMatrix, hints, err_handler);
+    if (err_handler.ErrCode() || rst.empty()) {
         // black white mirro!!!
         Ref<BitMatrix> invertedMatrix = image->getInvertedMatrix(err_handler);
-        if (err_handler.ErrCode() || invertedMatrix == NULL) return Ref<Result>();
-        Ref<Result> tmp_rst = decodeMore(image, invertedMatrix, hints, err_handler);
-        if (err_handler.ErrCode() || tmp_rst == NULL) return Ref<Result>();
-        return tmp_rst;
+        if (err_handler.ErrCode() || invertedMatrix == NULL) return result_list;
+        vector<Ref<Result>> tmp_rst = decodeMore(image, invertedMatrix, hints, err_handler);
+        if (err_handler.ErrCode() || tmp_rst.empty()) return tmp_rst;
     }
 
     return rst;
 }
 
-Ref<Result> QRCodeReader::decodeMore(Ref<BinaryBitmap> image, Ref<BitMatrix> imageBitMatrix,
+vector<Ref<Result>> QRCodeReader::decodeMore(Ref<BinaryBitmap> image, Ref<BitMatrix> imageBitMatrix,
                                      DecodeHints hints, ErrorHandler &err_handler) {
     nowHints_ = hints;
     std::string ept;
-
-    if (imageBitMatrix == NULL) return Ref<Result>();
+    vector<Ref<Result>> result_list;
+    if (imageBitMatrix == NULL) return result_list;
     image->m_poUnicomBlock->Init();
     image->m_poUnicomBlock->Reset(imageBitMatrix);
 
@@ -88,7 +88,7 @@ Ref<Result> QRCodeReader::decodeMore(Ref<BinaryBitmap> image, Ref<BitMatrix> ima
             Ref<FinderPatternInfo> patternInfo = detector->getFinderPatternInfo(i);
             setPatternFix(patternInfo->getPossibleFix());
             if (patternInfo->getAnglePossibleFix() < 0.6 && i) continue;
-
+            bool patternFoundFlag = false;
             int possibleAlignmentCount = 0;
             possibleAlignmentCount = detector->getPossibleAlignmentCount(i);
             if (possibleAlignmentCount < 0) continue;
@@ -99,6 +99,7 @@ Ref<Result> QRCodeReader::decodeMore(Ref<BinaryBitmap> image, Ref<BitMatrix> ima
 
             vector<bool> needTryVariousDeimensions(possibleAlignmentCount, false);
             for (int j = 0; j < possibleAlignmentCount; j++) {
+                if (patternFoundFlag){break;}
                 ArrayRef<Ref<ResultPoint> > points;
                 err_handler.Reset();
                 Ref<DetectorResult> detectorResult =
@@ -142,11 +143,12 @@ Ref<Result> QRCodeReader::decodeMore(Ref<BinaryBitmap> image, Ref<BitMatrix> ima
                                decoderResult->getCharset(), decoderResult->getQRCodeVersion(),
                                decoderResult->getEcLevel(), decoderResult->getCharsetMode()));
                 setSuccFix(points);
-
-                return result;
+                result_list.push_back(result);
+                patternFoundFlag = true;
             }
             // try different dimentions
             for (int j = 0; j < possibleAlignmentCount; j++) {
+                if (patternFoundFlag){break;}
                 err_handler.Reset();
                 ArrayRef<Ref<ResultPoint> > points;
                 if (needTryVariousDeimensions[j]) {
@@ -188,13 +190,14 @@ Ref<Result> QRCodeReader::decodeMore(Ref<BinaryBitmap> image, Ref<BitMatrix> ima
                             decoderResult->getEcLevel(), decoderResult->getCharsetMode()));
 
                         setSuccFix(points);
-                        return result;
+                        result_list.push_back(result);
+                        patternFoundFlag = true;
                     }
                 }
             }
         }
     }
-    return Ref<Result>();
+    return result_list;
 }
 
 vector<int> QRCodeReader::getPossibleDimentions(int detectDimension) {
diff --git a/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.hpp b/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.hpp
index bb0ccf61e..613286c2c 100644
--- a/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.hpp
+++ b/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.hpp
@@ -75,10 +75,10 @@ public:
     virtual ~QRCodeReader();
     string name() override { return "qrcode"; }
 
-    Ref<Result> decode(Ref<BinaryBitmap> image) override;
-    Ref<Result> decode(Ref<BinaryBitmap> image, DecodeHints hints) override;
+    vector<Ref<Result>> decode(Ref<BinaryBitmap> image) override;
+    vector<Ref<Result>> decode(Ref<BinaryBitmap> image, DecodeHints hints) override;
 
-    Ref<Result> decodeMore(Ref<BinaryBitmap> image, Ref<BitMatrix> imageBitMatrix,
+    vector<Ref<Result>> decodeMore(Ref<BinaryBitmap> image, Ref<BitMatrix> imageBitMatrix,
                            DecodeHints hints, ErrorHandler& err_handler);
 
 private:
diff --git a/modules/wechat_qrcode/src/zxing/reader.cpp b/modules/wechat_qrcode/src/zxing/reader.cpp
index da54ccb6b..7fa6b65f9 100644
--- a/modules/wechat_qrcode/src/zxing/reader.cpp
+++ b/modules/wechat_qrcode/src/zxing/reader.cpp
@@ -14,7 +14,7 @@ namespace zxing {
 
 Reader::~Reader() {}
 
-Ref<Result> Reader::decode(Ref<BinaryBitmap> image) { return decode(image, DecodeHints()); }
+vector<Ref<Result>> Reader::decode(Ref<BinaryBitmap> image) { return decode(image, DecodeHints()); }
 
 unsigned int Reader::getDecodeID() { return 0; }
 
diff --git a/modules/wechat_qrcode/src/zxing/reader.hpp b/modules/wechat_qrcode/src/zxing/reader.hpp
index cb3e7eaf3..e958013ca 100644
--- a/modules/wechat_qrcode/src/zxing/reader.hpp
+++ b/modules/wechat_qrcode/src/zxing/reader.hpp
@@ -23,8 +23,8 @@ protected:
     Reader() {}
 
 public:
-    virtual Ref<Result> decode(Ref<BinaryBitmap> image);
-    virtual Ref<Result> decode(Ref<BinaryBitmap> image, DecodeHints hints) = 0;
+    virtual vector<Ref<Result>> decode(Ref<BinaryBitmap> image);
+    virtual vector<Ref<Result>> decode(Ref<BinaryBitmap> image, DecodeHints hints) = 0;
 
     virtual ~Reader();
     virtual string name();

From f30e80e026074fcbf190acd47270bf3fcf7fcb00 Mon Sep 17 00:00:00 2001
From: sitong lian <563052165@qq.com>
Date: Wed, 7 Sep 2022 00:03:50 +0800
Subject: [PATCH 2/7] fix the bug that cannot detect multi qrcode when
 use_nn_detector is false

---
 .vscode/settings.json | 6 ------
 1 file changed, 6 deletions(-)
 delete mode 100644 .vscode/settings.json

diff --git a/.vscode/settings.json b/.vscode/settings.json
deleted file mode 100644
index 553817fbf..000000000
--- a/.vscode/settings.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-    "cquery.cacheDirectory": "${workspaceFolder}/.vscode/cquery_cached_index/",
-    "files.associations": {
-        "vector": "cpp"
-    }
-}
\ No newline at end of file

From 4c2283fa9952c241584936d64103cb059910408a Mon Sep 17 00:00:00 2001
From: sitong lian <563052165@qq.com>
Date: Wed, 7 Sep 2022 00:19:14 +0800
Subject: [PATCH 3/7] fix the bug that cannot detect multi qrcode when
 use_nn_detector is false

---
 .vscode/settings.json                    | 3 +++
 modules/wechat_qrcode/src/decodermgr.cpp | 6 +++---
 2 files changed, 6 insertions(+), 3 deletions(-)
 create mode 100644 .vscode/settings.json

diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 000000000..f5d622ff1
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,3 @@
+{
+    "cquery.cacheDirectory": "${workspaceFolder}/.vscode/cquery_cached_index/"
+}
\ No newline at end of file
diff --git a/modules/wechat_qrcode/src/decodermgr.cpp b/modules/wechat_qrcode/src/decodermgr.cpp
index 47a9ec775..9f8ad419a 100644
--- a/modules/wechat_qrcode/src/decodermgr.cpp
+++ b/modules/wechat_qrcode/src/decodermgr.cpp
@@ -45,10 +45,10 @@ int DecoderMgr::decodeImage(cv::Mat src, bool use_nn_detector, vector<string>& r
         }
         int ret = TryDecode(source, zx_results);
         if (!ret) {
-            for(unsigned int i=0; i<zx_results.size(); i++){
-                results.emplace_back(zx_result->getText()->getText());
+            for(unsigned int k=0; k<zx_results.size(); k++){
+                results.emplace_back(zx_results[k]->getText()->getText());
                 vector<Point2f> tmp_qr_points;
-                auto tmp_zx_points = zx_results[i]->getResultPoints();
+                auto tmp_zx_points = zx_results[k]->getResultPoints();
                 for(int i = 0; i < tmp_zx_points->size() / 4; i++) {
                     const int ind = i * 4;
                     for (int j = 1; j < 4; j++){

From 5d9067933e59436f48066bcb9326b8972a68ae74 Mon Sep 17 00:00:00 2001
From: sitong lian <563052165@qq.com>
Date: Wed, 7 Sep 2022 00:22:33 +0800
Subject: [PATCH 4/7] fix the bug that cannot detect multi qrcode when
 use_nn_detector is false

---
 .vscode/settings.json | 3 ---
 1 file changed, 3 deletions(-)
 delete mode 100644 .vscode/settings.json

diff --git a/.vscode/settings.json b/.vscode/settings.json
deleted file mode 100644
index f5d622ff1..000000000
--- a/.vscode/settings.json
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-    "cquery.cacheDirectory": "${workspaceFolder}/.vscode/cquery_cached_index/"
-}
\ No newline at end of file

From 14157b140ea83777dede37cd7dbeb75c64fc7a7a Mon Sep 17 00:00:00 2001
From: AleksandrPanov <alexander.panov@xperience.ai>
Date: Mon, 19 Sep 2022 23:13:05 +0300
Subject: [PATCH 5/7] fixed duplicate corners and style

---
 modules/wechat_qrcode/src/decodermgr.cpp    |  6 ++---
 modules/wechat_qrcode/src/wechat_qrcode.cpp | 27 ++++++++++++++++++---
 2 files changed, 27 insertions(+), 6 deletions(-)

diff --git a/modules/wechat_qrcode/src/decodermgr.cpp b/modules/wechat_qrcode/src/decodermgr.cpp
index 9f8ad419a..1e93aa15c 100644
--- a/modules/wechat_qrcode/src/decodermgr.cpp
+++ b/modules/wechat_qrcode/src/decodermgr.cpp
@@ -45,14 +45,14 @@ int DecoderMgr::decodeImage(cv::Mat src, bool use_nn_detector, vector<string>& r
         }
         int ret = TryDecode(source, zx_results);
         if (!ret) {
-            for(unsigned int k=0; k<zx_results.size(); k++){
+            for(size_t k = 0; k < zx_results.size(); k++) {
                 results.emplace_back(zx_results[k]->getText()->getText());
                 vector<Point2f> tmp_qr_points;
                 auto tmp_zx_points = zx_results[k]->getResultPoints();
-                for(int i = 0; i < tmp_zx_points->size() / 4; i++) {
+                for (int i = 0; i < tmp_zx_points->size() / 4; i++) {
                     const int ind = i * 4;
                     for (int j = 1; j < 4; j++){
-                        tmp_qr_points.emplace_back(tmp_zx_points[ind+j]->getX(), tmp_zx_points[ind+j]->getY());
+                        tmp_qr_points.emplace_back(tmp_zx_points[ind + j]->getX(), tmp_zx_points[ind + j]->getY());
                     }
                     tmp_qr_points.emplace_back(tmp_zx_points[ind]->getX(), tmp_zx_points[ind]->getY());
                 }
diff --git a/modules/wechat_qrcode/src/wechat_qrcode.cpp b/modules/wechat_qrcode/src/wechat_qrcode.cpp
index 596a72269..f4bec7c2b 100644
--- a/modules/wechat_qrcode/src/wechat_qrcode.cpp
+++ b/modules/wechat_qrcode/src/wechat_qrcode.cpp
@@ -144,10 +144,10 @@ vector<string> WeChatQRCode::Impl::decode(const Mat& img, vector<Mat>& candidate
                 super_resolution_model_->processImageScale(cropped_img, cur_scale, use_nn_sr_);
             string result;
             DecoderMgr decodemgr;
-            vector<vector<Point2f>> zxing_points;
+            vector<vector<Point2f>> zxing_points, check_points;
             auto ret = decodemgr.decodeImage(scaled_img, use_nn_detector_, decode_results, zxing_points);
             if (ret == 0) {
-                for(unsigned int i=0; i<zxing_points.size(); ++i){
+                for(size_t i = 0; i <zxing_points.size(); i++){
                     vector<Point2f> points_qr = zxing_points[i];
                     for (auto&& pt: points_qr) {
                         pt /= cur_scale;
@@ -159,7 +159,28 @@ vector<string> WeChatQRCode::Impl::decode(const Mat& img, vector<Mat>& candidate
                         point.at<float>(j, 0) = points_qr[j].x;
                         point.at<float>(j, 1) = points_qr[j].y;
                     }
-                    points.push_back(point);
+                    // try to find duplicate qr corners
+                    bool isDuplicate = false;
+                    for (const auto &tmp_points: check_points) {
+                        const float eps = 10.f;
+                        for (size_t j = 0; j < tmp_points.size(); j++) {
+                            if (abs(tmp_points[j].x - points_qr[j].x) < eps &&
+                                abs(tmp_points[j].y - points_qr[j].y) < eps) {
+                                isDuplicate = true;
+                            }
+                            else {
+                                isDuplicate = false;
+                                break;
+                            }
+                        }
+                    }
+                    if (isDuplicate == false) {
+                        points.push_back(point);
+                        check_points.push_back(points_qr);
+                    }
+                    else {
+                        decode_results.erase(decode_results.begin() + i, decode_results.begin() + i + 1);
+                    }
                 }
                 break;
             }

From cfcfd5f4114a6014d93345a82ea397c2cc1aeb40 Mon Sep 17 00:00:00 2001
From: AleksandrPanov <alexander.panov@xperience.ai>
Date: Mon, 19 Sep 2022 23:13:42 +0300
Subject: [PATCH 6/7] add multi detect test

---
 modules/wechat_qrcode/test/test_qrcode.cpp | 47 ++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/modules/wechat_qrcode/test/test_qrcode.cpp b/modules/wechat_qrcode/test/test_qrcode.cpp
index 49a34978a..d59932b81 100644
--- a/modules/wechat_qrcode/test/test_qrcode.cpp
+++ b/modules/wechat_qrcode/test/test_qrcode.cpp
@@ -408,5 +408,52 @@ TEST(Objdetect_QRCode_Tiny, regression) {
     ASSERT_EQ(expect_msg, decoded_info[0]);
 }
 
+
+typedef testing::TestWithParam<std::string> Objdetect_QRCode_Easy_Multi;
+TEST_P(Objdetect_QRCode_Easy_Multi, regression) {
+    string path_detect_prototxt, path_detect_caffemodel, path_sr_prototxt, path_sr_caffemodel;
+    string model_path = GetParam();
+
+    if (!model_path.empty()) {
+        path_detect_prototxt = findDataFile(model_path + "/detect.prototxt", false);
+        path_detect_caffemodel = findDataFile(model_path + "/detect.caffemodel", false);
+        path_sr_prototxt = findDataFile(model_path + "/sr.prototxt", false);
+        path_sr_caffemodel = findDataFile(model_path + "/sr.caffemodel", false);
+    }
+
+    auto detector = wechat_qrcode::WeChatQRCode(path_detect_prototxt, path_detect_caffemodel, path_sr_prototxt,
+                                                path_sr_caffemodel);
+
+    const cv::String expect_msg1 = "OpenCV1", expect_msg2 = "OpenCV2";
+    QRCodeEncoder::Params params;
+    params.version = 4; // 33x33
+    Ptr<QRCodeEncoder> qrcode_enc = cv::QRCodeEncoder::create(params);
+    Mat qrImage1, qrImage2;
+    qrcode_enc->encode(expect_msg1, qrImage1);
+    qrcode_enc->encode(expect_msg2, qrImage2);
+    const int pixInBlob = 2;
+    const int offset = 14;
+    const int qr_size = (params.version - 1) * 4 + 21;
+    Mat tinyImage = Mat::zeros(qr_size*pixInBlob+offset, (qr_size*pixInBlob+offset)*2, CV_8UC1);
+    Size qrSize = Size(qrImage1.cols, qrImage1.rows);
+
+    Mat roiImage = tinyImage(Rect((tinyImage.cols/2 - qrSize.width)/2, (tinyImage.rows - qrSize.height)/2,
+                                   qrSize.width, qrSize.height));
+    cv::resize(qrImage1, roiImage, qrSize, 1., 1., INTER_NEAREST);
+
+    roiImage = tinyImage(Rect((tinyImage.cols/2 - qrSize.width)/2+tinyImage.cols/2, (tinyImage.rows - qrSize.height)/2,
+                                   qrSize.width, qrSize.height));
+    cv::resize(qrImage2, roiImage, qrSize, 1., 1., INTER_NEAREST);
+
+    vector<Mat> points;
+    auto decoded_info = detector.detectAndDecode(tinyImage, points);
+    ASSERT_EQ(2ull, decoded_info.size());
+    ASSERT_TRUE((expect_msg1 == decoded_info[0] && expect_msg2 == decoded_info[1]) ||
+                (expect_msg1 == decoded_info[1] && expect_msg2 == decoded_info[0]));
+}
+
+std::string qrcode_model_path[] = {"", "dnn/wechat_2021-01"};
+INSTANTIATE_TEST_CASE_P(/**/, Objdetect_QRCode_Easy_Multi, testing::ValuesIn(qrcode_model_path));
+
 }  // namespace
 }  // namespace opencv_test

From a3afb879cab6898a6be787ff6fd2f1cc04beb63f Mon Sep 17 00:00:00 2001
From: AleksandrPanov <alexander.panov@xperience.ai>
Date: Tue, 20 Sep 2022 11:37:53 +0300
Subject: [PATCH 7/7] add return for nn_detector

---
 modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.cpp b/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.cpp
index c5b526263..b6c4c4f71 100644
--- a/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.cpp
+++ b/modules/wechat_qrcode/src/zxing/qrcode/qrcode_reader.cpp
@@ -145,6 +145,9 @@ vector<Ref<Result>> QRCodeReader::decodeMore(Ref<BinaryBitmap> image, Ref<BitMat
                 setSuccFix(points);
                 result_list.push_back(result);
                 patternFoundFlag = true;
+                if (nowHints_.getUseNNDetector()) {
+                    return result_list;
+                }
             }
             // try different dimentions
             for (int j = 0; j < possibleAlignmentCount; j++) {
@@ -192,6 +195,9 @@ vector<Ref<Result>> QRCodeReader::decodeMore(Ref<BinaryBitmap> image, Ref<BitMat
                         setSuccFix(points);
                         result_list.push_back(result);
                         patternFoundFlag = true;
+                        if (nowHints_.getUseNNDetector()) {
+                            return result_list;
+                        }
                     }
                 }
             }