Update radon_transform.cpp

Author: sturkmen72

modules/ximgproc/src/radon_transform.cpp

@@ -5,77 +5,80 @@
 #include "precomp.hpp"
 
 namespace cv {namespace ximgproc {
-    void RadonTransform(InputArray src,
-                             OutputArray dst,
-                             double theta,
-                             double start_angle,
-                             double end_angle,
-                             bool crop,
-                             bool norm)
-    {
-        CV_Assert(src.dims() == 2);
-        CV_Assert(src.channels() == 1);
-        CV_Assert((end_angle - start_angle) * theta > 0);
+void RadonTransform(InputArray src,
+                    OutputArray dst,
+                    double theta,
+                    double start_angle,
+                    double end_angle,
+                    bool crop,
+                    bool norm)
+{
+    CV_Assert(src.dims() == 2);
+    CV_Assert(src.channels() == 1);
+    CV_Assert((end_angle - start_angle) * theta > 0);
 
-        Mat _srcMat = src.getMat();
+    int col_num = cvRound((end_angle - start_angle) / theta);
+    int row_num, out_mat_type;
+    Point center;
+    Mat srcMat, masked_src;
 
-        int _row_num, _col_num, _out_mat_type;
-        _col_num = cvRound((end_angle - start_angle) / theta);
-        transpose(_srcMat, _srcMat);
-        Mat _masked_src;
-        cv::Point _center;
+    transpose(src, srcMat);
 
-        if (_srcMat.type() == CV_32FC1 || _srcMat.type() == CV_64FC1) {
-            _out_mat_type = CV_64FC1;
-        }
-        else {
-            _out_mat_type = CV_32SC1;
-        }
+    if (srcMat.type() == CV_32FC1 || srcMat.type() == CV_64FC1) {
+        out_mat_type = CV_64FC1;
+    }
+    else {
+        out_mat_type = CV_32SC1;
+    }
 
-        if (crop) {
-            // crop the source into square
-            _row_num = min(_srcMat.rows, _srcMat.cols);
-            cv::Rect _crop_ROI(
-                _srcMat.cols / 2 - _row_num / 2,
-                _srcMat.rows / 2 - _row_num / 2,
-                _row_num, _row_num);
-            _srcMat = _srcMat(_crop_ROI);
-            // crop the source into circle
-            Mat _mask(_srcMat.size(), CV_8UC1, Scalar(0));
-            _center = Point(_srcMat.cols / 2, _srcMat.rows / 2);
-            circle(_mask, _center, _srcMat.cols / 2, Scalar(255), FILLED);
-            _srcMat.copyTo(_masked_src, _mask);
-        }
-        else {
-            // avoid cropping corner when rotating
-            _row_num = cvCeil(sqrt(_srcMat.rows * _srcMat.rows + _srcMat.cols * _srcMat.cols));
-            _masked_src = Mat(Size(_row_num, _row_num), _srcMat.type(), Scalar(0));
-            _center = Point(_masked_src.cols / 2, _masked_src.rows / 2);
-            _srcMat.copyTo(_masked_src(Rect(
-                (_row_num - _srcMat.cols) / 2,
-                (_row_num - _srcMat.rows) / 2,
-                _srcMat.cols, _srcMat.rows)));
-        }
+    if (crop) {
+        // Crop the source into square
+        row_num = min(srcMat.rows, srcMat.cols);
+        Rect crop_ROI(
+            srcMat.cols / 2 - row_num / 2,
+            srcMat.rows / 2 - row_num / 2,
+            row_num, row_num);
+        srcMat = srcMat(crop_ROI);
 
-        double _t;
-        Mat _rotated_src;
-        Mat _radon(_row_num, _col_num, _out_mat_type);
+        // Crop the source into circle
+        Mat mask(srcMat.size(), CV_8UC1, Scalar(0));
+        center = Point(srcMat.cols / 2, srcMat.rows / 2);
+        circle(mask, center, srcMat.cols / 2, Scalar(255), FILLED);
+        srcMat.copyTo(masked_src, mask);
+    }
+    else {
+        // Avoid cropping corner when rotating
+        row_num = cvCeil(sqrt(srcMat.rows * srcMat.rows + srcMat.cols * srcMat.cols));
+        masked_src = Mat(Size(row_num, row_num), srcMat.type(), Scalar(0));
+        center = Point(masked_src.cols / 2, masked_src.rows / 2);
+        srcMat.copyTo(masked_src(Rect(
+            (row_num - srcMat.cols) / 2,
+            (row_num - srcMat.rows) / 2,
+            srcMat.cols, srcMat.rows)));
+    }
 
-        for (int _col = 0; _col < _col_num; _col++) {
-            // rotate the source by _t
-            _t = (start_angle + _col * theta);
-            cv::Mat _r_matrix = cv::getRotationMatrix2D(_center, _t, 1);
-            cv::warpAffine(_masked_src, _rotated_src, _r_matrix, _masked_src.size());
-            Mat _col_mat = _radon.col(_col);
-            // make projection
-            cv::reduce(_rotated_src, _col_mat, 1, REDUCE_SUM, _out_mat_type);
-        }
+    Mat radon(row_num, col_num, out_mat_type);
 
-        if (norm) {
-            normalize(_radon, _radon, 0, 255, NORM_MINMAX, CV_8UC1);
+    // Define the parallel loop as a lambda function
+    parallel_for_(Range(0, col_num), [&](const Range& range) {
+        for (int col = range.start; col < range.end; col++) {
+            // Rotate the source by t
+            double t = (start_angle + col * theta);
+            Mat r_matrix = getRotationMatrix2D(center, t, 1);
+
+            Mat rotated_src;
+            warpAffine(masked_src, rotated_src, r_matrix, masked_src.size());
+
+            Mat col_mat = radon.col(col);
+            // Make projection
+            reduce(rotated_src, col_mat, 1, REDUCE_SUM, out_mat_type);
         }
+    });
 
-        _radon.copyTo(dst);
-        return;
+    if (norm) {
+        normalize(radon, radon, 0, 255, NORM_MINMAX, CV_8UC1);
     }
+
+    radon.copyTo(dst);
+}
 } }