add scaleFactor/setScaleFactor/getScaleFactor

add test

add dnn data search

Author: AleksandrPanov

modules/wechat_qrcode/CMakeLists.txt

@@ -1,5 +1,5 @@
 set(the_description "WeChat QR code Detector")
-ocv_define_module(wechat_qrcode opencv_core opencv_imgproc opencv_dnn WRAP java objc python js)
+ocv_define_module(wechat_qrcode opencv_core opencv_imgproc opencv_objdetect opencv_dnn WRAP java objc python js)
 
 # iconv support isn't automatic on some systems
 if(CMAKE_VERSION VERSION_GREATER "3.11")

modules/wechat_qrcode/include/opencv2/wechat_qrcode.hpp

@@ -48,8 +48,23 @@ class CV_EXPORTS_W WeChatQRCode {
      * empty if not found.
      * @return list of decoded string.
      */
-    CV_WRAP std::vector<std::string> detectAndDecode(InputArray img,
-                                                     OutputArrayOfArrays points = noArray());
+    CV_WRAP std::vector<std::string> detectAndDecode(InputArray img, OutputArrayOfArrays points = noArray());
+
+    /**
+    * @brief set scale factor
+    * QR code detector use neural network to detect QR.
+    * Before running the neural network, the input image is pre-processed by scaling.
+    * By default, the input image is scaled to an image with an area of 160000 pixels.
+    * The scale factor allows to use custom scale the input image:
+    * width = scaleFactor*width
+    * height = scaleFactor*width
+    *
+    * scaleFactor valuse must be > 0 and <= 1, otherwise the scaleFactor value is set to -1
+    * and use default scaled to an image with an area of 160000 pixels.
+    */
+    CV_WRAP void setScaleFactor(float _scalingFactor);
+
+    CV_WRAP float getScaleFactor();
 
 protected:
     class Impl;

modules/wechat_qrcode/src/wechat_qrcode.cpp

@@ -43,6 +43,7 @@ class WeChatQRCode::Impl {
     std::shared_ptr<SSDDetector> detector_;
     std::shared_ptr<SuperScale> super_resolution_model_;
     bool use_nn_detector_, use_nn_sr_;
+    float scaleFactor = -1.f;
 };
 
 WeChatQRCode::WeChatQRCode(const String& detector_prototxt_path,
@@ -109,6 +110,17 @@ vector<string> WeChatQRCode::detectAndDecode(InputArray img, OutputArrayOfArrays
         points.assign(tmp_points);
     }
     return ret;
+}
+
+void WeChatQRCode::setScaleFactor(float _scaleFactor) {
+    if (_scaleFactor > 0 && _scaleFactor <= 1.f)
+        p->scaleFactor = _scaleFactor;
+    else
+        p->scaleFactor = -1.f;
+};
+
+float WeChatQRCode::getScaleFactor() {
+    return p->scaleFactor;
 };
 
 vector<string> WeChatQRCode::Impl::decode(const Mat& img, vector<Mat>& candidate_points,
@@ -173,11 +185,11 @@ int WeChatQRCode::Impl::applyDetector(const Mat& img, vector<Mat>& points) {
     int img_w = img.cols;
     int img_h = img.rows;
 
+    const float targetArea = 400.f * 400.f;
     // hard code input size
-    int minInputSize = 400;
-    float resizeRatio = sqrt(img_w * img_h * 1.0 / (minInputSize * minInputSize));
-    int detect_width = img_w / resizeRatio;
-    int detect_height = img_h / resizeRatio;
+    const float tmpScaleFactor = scaleFactor == -1.f ? sqrt(targetArea / (img_w * img_h)) : scaleFactor;
+    int detect_width = img_w * tmpScaleFactor;
+    int detect_height = img_h * tmpScaleFactor;
 
     points = detector_->forward(img, detect_width, detect_height);
 

modules/wechat_qrcode/test/test_main.cpp

@@ -11,4 +11,19 @@
 #include <hpx/hpx_main.hpp>
 #endif
 
-CV_TEST_MAIN("cv")
+static
+void initTests()
+{
+#ifdef HAVE_OPENCV_DNN
+    const char* extraTestDataPath =
+#ifdef WINRT
+        NULL;
+#else
+        getenv("OPENCV_DNN_TEST_DATA_PATH");
+#endif
+    if (extraTestDataPath)
+        cvtest::addDataSearchPath(extraTestDataPath);
+#endif  // HAVE_OPENCV_DNN
+}
+
+CV_TEST_MAIN("cv", initTests())

modules/wechat_qrcode/test/test_qrcode.cpp

@@ -6,6 +6,7 @@
 // Copyright (C) 2020 THL A29 Limited, a Tencent company. All rights reserved.
 
 #include "test_precomp.hpp"
+#include "opencv2/objdetect.hpp"
 
 namespace opencv_test {
 namespace {
@@ -289,5 +290,37 @@ INSTANTIATE_TEST_CASE_P(/**/, Objdetect_QRCode_Monitor, testing::ValuesIn(qrcode
 INSTANTIATE_TEST_CASE_P(/**/, Objdetect_QRCode_Curved, testing::ValuesIn(qrcode_images_curved));
 // INSTANTIATE_TEST_CASE_P(/**/, Objdetect_QRCode_Multi, testing::ValuesIn(qrcode_images_multiple));
 
+TEST(Objdetect_QRCode_Big, regression) {
+    string path_detect_prototxt, path_detect_caffemodel, path_sr_prototxt, path_sr_caffemodel;
+    string model_version = "_2021-01";
+    path_detect_prototxt = findDataFile("dnn/wechat"+model_version+"/detect.prototxt", false);
+    path_detect_caffemodel = findDataFile("dnn/wechat"+model_version+"/detect.caffemodel", false);
+    path_sr_prototxt = findDataFile("dnn/wechat"+model_version+"/sr.prototxt", false);
+    path_sr_caffemodel = findDataFile("dnn/wechat"+model_version+"/sr.caffemodel", false);
+
+    auto detector = wechat_qrcode::WeChatQRCode(path_detect_prototxt, path_detect_caffemodel, path_sr_prototxt,
+                                                path_sr_caffemodel);
+
+    const cv::String expect_msg = "OpenCV";
+    QRCodeEncoder::Params params;
+    params.version = 4; // 33x33
+    Ptr<QRCodeEncoder> qrcode_enc = cv::QRCodeEncoder::create(params);
+    Mat qrImage;
+    qrcode_enc->encode(expect_msg, qrImage);
+    Mat largeImage(4032, 3024, CV_8UC1);
+    const int pixInBlob = 4;
+    Size qrSize = Size((21+(params.version-1)*4)*pixInBlob,(21+(params.version-1)*4)*pixInBlob);
+    Mat roiImage = largeImage(Rect((largeImage.cols - qrSize.width)/2, (largeImage.rows - qrSize.height)/2,
+                                   qrSize.width, qrSize.height));
+    cv::resize(qrImage, roiImage, qrSize, 1., 1., INTER_NEAREST);
+
+    vector<Mat> points;
+    detector.setScaleFactor(0.25f);
+    auto decoded_info = detector.detectAndDecode(largeImage, points);
+    ASSERT_EQ(1ull, decoded_info.size());
+    ASSERT_EQ(expect_msg, decoded_info[0]);
+}
+
+
 }  // namespace
 }  // namespace opencv_test