modified data matrix detection interface (that does not use any new data…

modified data matrix detection interface (that does not use any new data structures). Added Python sample for data matrix detection. Ticket #1664

modules/core/include/opencv2/core/core.hpp

@@ -2142,11 +2142,11 @@ CV_EXPORTS Mat repeat(const Mat& src, int ny, int nx);
         
 CV_EXPORTS void hconcat(const Mat* src, size_t nsrc, OutputArray dst);
 CV_EXPORTS void hconcat(InputArray src1, InputArray src2, OutputArray dst);
-CV_EXPORTS_W void hconcat(InputArray src, OutputArray dst);
+CV_EXPORTS_W void hconcat(InputArrayOfArrays src, OutputArray dst);
 
 CV_EXPORTS void vconcat(const Mat* src, size_t nsrc, OutputArray dst);
 CV_EXPORTS void vconcat(InputArray src1, InputArray src2, OutputArray dst);
-CV_EXPORTS_W void vconcat(InputArray src, OutputArray dst);
+CV_EXPORTS_W void vconcat(InputArrayOfArrays src, OutputArray dst);
     
 //! computes bitwise conjunction of the two arrays (dst = src1 & src2)
 CV_EXPORTS_W void bitwise_and(InputArray src1, InputArray src2,

modules/objdetect/include/opencv2/objdetect/objdetect.hpp

@@ -586,16 +586,13 @@ public:
 };
 
 
-    
-    
-struct CV_EXPORTS DataMatrixCode {
-  char msg[4]; //TODO std::string
-  Mat original;
-  Point corners[4]; //TODO vector
-};
-
-CV_EXPORTS void findDataMatrix(const Mat& image, std::vector<DataMatrixCode>& codes);
-CV_EXPORTS  void drawDataMatrixCodes(const std::vector<DataMatrixCode>& codes, Mat& drawImage);
+CV_EXPORTS_W void findDataMatrix(InputArray image,
+                                 CV_OUT vector<string>& codes,
+                                 OutputArray corners=noArray(),
+                                 OutputArrayOfArrays dmtx=noArray());
+CV_EXPORTS_W void drawDataMatrixCodes(InputOutputArray image,
+                                      const vector<string>& codes,
+                                      InputArray corners);
 }
 
 /****************************************************************************************\

modules/objdetect/src/datamatrix.cpp

@@ -496,60 +496,80 @@ endo: ; // end search for this o
 
 namespace cv
 {
-namespace
+    
+void findDataMatrix(InputArray _image,
+                    vector<string>& codes,
+                    OutputArray _corners,
+                    OutputArrayOfArrays _dmtx)
 {
-  struct CvDM2DM_transform
-  {
-    DataMatrixCode operator()(CvDataMatrixCode& cvdm)
+    Mat image = _image.getMat();
+    CvMat m(image);
+    deque <CvDataMatrixCode> rc = cvFindDataMatrix(&m);
+    int i, n = (int)rc.size();
+    Mat corners;
+    
+    if( _corners.needed() )
     {
-      DataMatrixCode dm;
-      memcpy(dm.msg,cvdm.msg,sizeof(cvdm.msg));
-      dm.original = cv::Mat(cvdm.original,true);
-      cvReleaseMat(&cvdm.original);
-      cv::Mat c(cvdm.corners,true);
-      dm.corners[0] = c.at<Point>(0,0);
-      dm.corners[1] = c.at<Point>(1,0);
-      dm.corners[2] = c.at<Point>(2,0);
-      dm.corners[3] = c.at<Point>(3,0);
-      cvReleaseMat(&cvdm.corners);
-      return dm;
-    }
-  };
-  
-  struct DrawDataMatrixCode
+        _corners.create(n, 4, CV_32SC2);
+        corners = _corners.getMat();
+    }
+    
+    if( _dmtx.needed() )
+        _dmtx.create(n, 1, CV_8U);
+    
+    codes.resize(n);
+    
+    for( i = 0; i < n; i++ )
     {
-    DrawDataMatrixCode(cv::Mat& image):image(image){}
-    void operator()(const DataMatrixCode& code)
+        CvDataMatrixCode& rc_i = rc[i];
+        codes[i] = string(rc_i.msg);
+        
+        if( corners.data )
         {
-      Scalar c(0, 255, 0);
-      Scalar c2(255, 0,0);
-      line(image, code.corners[0], code.corners[1], c);
-      line(image, code.corners[1], code.corners[2], c);
-      line(image, code.corners[2], code.corners[3], c);
-      line(image, code.corners[3], code.corners[0], c);
-      string code_text(code.msg,4);
-      //int baseline = 0;
-      //Size sz = getTextSize(code_text, CV_FONT_HERSHEY_SIMPLEX, 1, 1, &baseline);
-      putText(image, code_text, code.corners[0], CV_FONT_HERSHEY_SIMPLEX, 0.8, c2, 1, CV_AA, false);
+            const Point* srcpt = (Point*)rc_i.corners->data.ptr;
+            Point* dstpt = (Point*)corners.ptr(i);
+            for( int k = 0; k < 4; k++ )
+                dstpt[k] = srcpt[k];
         }
-    cv::Mat& image;
+        cvReleaseMat(&rc_i.corners);
         
-    DrawDataMatrixCode& operator=(const DrawDataMatrixCode&);
-  };
+        if( _dmtx.needed() )
+        {
+            _dmtx.create(rc_i.original->rows, rc_i.original->cols, rc_i.original->type, i);
+            Mat dst = _dmtx.getMat(i);
+            Mat(rc_i.original).copyTo(dst);
+        }
+        cvReleaseMat(&rc_i.original);
+    }
 }
 
-void findDataMatrix(const cv::Mat& image, std::vector<DataMatrixCode>& codes)
+void drawDataMatrixCodes(InputOutputArray _image,
+                         const vector<string>& codes,
+                         InputArray _corners)
 {
-  CvMat m(image);
-  deque <CvDataMatrixCode> rc = cvFindDataMatrix(&m);
-  codes.clear();
-  codes.resize(rc.size());
-  std::transform(rc.begin(),rc.end(),codes.begin(),CvDM2DM_transform());  
-}
+    Mat image = _image.getMat();
+    Mat corners = _corners.getMat();
+    int i, n = corners.rows;
     
-void drawDataMatrixCodes(const std::vector<DataMatrixCode>& codes, Mat& drawImage)
-{
-  std::for_each(codes.begin(),codes.end(),DrawDataMatrixCode(drawImage));
+    if( n > 0 )
+    {
+        CV_Assert( corners.depth() == CV_32S &&
+                  corners.cols*corners.channels() == 8 &&
+                  n == (int)codes.size() );
+    }
+    
+    for( i = 0; i < n; i++ )
+    {
+        Scalar c(0, 255, 0);
+        Scalar c2(255, 0,0);
+        const Point* pt = (const Point*)corners.ptr(i);
+        
+        for( int k = 0; k < 4; k++ )
+            line(image, pt[k], pt[(k+1)%4], c);
+        //int baseline = 0;
+        //Size sz = getTextSize(code_text, CV_FONT_HERSHEY_SIMPLEX, 1, 1, &baseline);
+        putText(image, codes[i], pt[0], CV_FONT_HERSHEY_SIMPLEX, 0.8, c2, 1, CV_AA, false);
+    }
 }
     
 }

samples/cpp/video_dmtx.cpp

@@ -21,8 +21,8 @@ using namespace std;
 //hide the local functions in an anon namespace
 namespace
 {
-void help(char** av)
-{
+    void help(char** av)
+    {
         cout << "\nThis program justs gets you started reading images from video\n"
         "Usage:\n./" << av[0] << " <video device number>\n" << "q,Q,esc -- quit\n"
         << "space   -- save frame\n\n"
@@ -36,11 +36,10 @@ void help(char** av)
         << "  NOTE: This only handles strings of len 3 or less\n"
         << "  Resize the screen to be large enough for your camera to see, and it should find an read it.\n\n"
         << endl;
-}
+    }
     
-int process(VideoCapture& capture)
-{
-  std::vector<DataMatrixCode> codes;
+    int process(VideoCapture& capture)
+    {
         int n = 0;
         char filename[200];
         string window_name = "video | q or esc to quit";
@@ -54,8 +53,10 @@ int process(VideoCapture& capture)
                 break;
             cv::Mat gray;
             cv::cvtColor(frame,gray,CV_RGB2GRAY);
-    findDataMatrix(gray, codes);
-    drawDataMatrixCodes(codes, frame);
+            vector<string> codes;
+            Mat corners;
+            findDataMatrix(gray, codes, corners);
+            drawDataMatrixCodes(frame, codes, corners);
             imshow(window_name, frame);
             char key = (char) waitKey(5); //delay N millis, usually long enough to display and capture input
             switch (key)
@@ -74,7 +75,7 @@ int process(VideoCapture& capture)
             }
         }
         return 0;
-}
+    }
     
 }
 

samples/python2/video_dmtx.py

+help='''
+Data matrix detector sample.
+Usage:
+   video_dmtx {<video device number>|<video file name>}
+
+   Generate a datamatrix from  from http://datamatrix.kaywa.com/ and print it out.
+   NOTE: This only handles data matrices, generated for text strings of max 3 characters
+
+   Resize the screen to be large enough for your camera to see, and it should find an read it.
+   
+Keyboard shortcuts:
+
+   q or ESC - exit
+   space - save current image as datamatrix<frame_number>.jpg
+'''
+
+import cv2
+import numpy as np
+import sys
+
+def data_matrix_demo(cap):
+    window_name = "Data Matrix Detector"
+    frame_number = 0
+    need_to_save = False
+    
+    while 1:
+        ret, frame = cap.read()
+        if not ret:
+            break
+            
+        gray = cv2.cvtColor(frame, cv2.COLOR_RGB2GRAY)
+        codes, corners, dmtx = cv2.findDataMatrix(gray)
+        
+        cv2.drawDataMatrixCodes(frame, codes, corners)
+        cv2.imshow(window_name, frame)
+        
+        key = cv2.waitKey(30)
+        c = chr(key & 255)
+        if c in ['q', 'Q', chr(27)]:
+            break
+            
+        if c == ' ':
+            need_to_save = True
+            
+        if need_to_save and codes:
+            filename = ("datamatrix%03d.jpg" % frame_number)
+            cv2.imwrite(filename, frame)
+            print "Saved frame to " + filename
+            need_to_save = False
+            
+        frame_number += 1
+
+
+if __name__ == '__main__':
+    print help
+
+    if len(sys.argv) == 1:
+        cap = cv2.VideoCapture(0)
+    else:
+        cap = cv2.VideoCapture(sys.argv[1])
+        if not cap.isOpened():
+            cap = cv2.VideoCapture(int(sys.argv[1]))
+        
+    if not cap.isOpened():
+        print 'Cannot initialize video capture'
+        sys.exit(-1)
+        
+    data_matrix_demo(cap)