added support of multichannel matrices in gpu::minMax

modules/gpu/src/arithm.cpp

@@ -496,34 +496,34 @@ namespace cv { namespace gpu { namespace mathfunc {
 
 void cv::gpu::minMax(const GpuMat& src, double* minVal, double* maxVal)
 {
-    CV_Assert(src.channels() == 1);
+    GpuMat src_ = src.reshape(1);
 
     double maxVal_;
     if (!maxVal) 
         maxVal = &maxVal_;
   
-    switch (src.type())
+    switch (src_.type())
     {
     case CV_8U:
-        mathfunc::min_max_caller<unsigned char>(src, minVal, maxVal);
+        mathfunc::min_max_caller<unsigned char>(src_, minVal, maxVal);
         break;
     case CV_8S:
-        mathfunc::min_max_caller<signed char>(src, minVal, maxVal);
+        mathfunc::min_max_caller<signed char>(src_, minVal, maxVal);
         break;
     case CV_16U:
-        mathfunc::min_max_caller<unsigned short>(src, minVal, maxVal);
+        mathfunc::min_max_caller<unsigned short>(src_, minVal, maxVal);
         break;
     case CV_16S:
-        mathfunc::min_max_caller<signed short>(src, minVal, maxVal);
+        mathfunc::min_max_caller<signed short>(src_, minVal, maxVal);
         break;
     case CV_32S:
-        mathfunc::min_max_caller<int>(src, minVal, maxVal);
+        mathfunc::min_max_caller<int>(src_, minVal, maxVal);
         break;
     case CV_32F:
-        mathfunc::min_max_caller<float>(src, minVal, maxVal);
+        mathfunc::min_max_caller<float>(src_, minVal, maxVal);
         break;
     case CV_64F:
-        mathfunc::min_max_caller<double>(src, minVal, maxVal);
+        mathfunc::min_max_caller<double>(src_, minVal, maxVal);
         break;
     default:
         CV_Error(CV_StsBadArg, "Unsupported type");

tests/gpu/src/arithm.cpp

@@ -678,22 +678,23 @@ struct CV_GpuMinMaxTest: public CvTest
 
     void run(int)
     {
-        for (int type = CV_8U; type <= CV_64F; ++type)
+        for (int cn = 1; cn <= 4; ++cn)
+            for (int depth = CV_8U; depth <= CV_64F; ++depth)
             {
                 int rows = 1, cols = 3;
-            test(rows, cols, type);
+                test(rows, cols, cn, depth);
                 for (int i = 0; i < 4; ++i)
                 {
                     int rows = 1 + rand() % 1000;
                     int cols = 1 + rand() % 1000;
-                test(rows, cols, type);
+                    test(rows, cols, cn, depth);
                 }
             }
     }
 
-    void test(int rows, int cols, int type)
+    void test(int rows, int cols, int cn, int depth)
     {
-        cv::Mat src(rows, cols, type);
+        cv::Mat src(rows, cols, CV_MAKE_TYPE(depth, cn));
         cv::RNG rng;
         for (int i = 0; i < src.rows; ++i)
         { 
@@ -702,20 +703,21 @@ struct CV_GpuMinMaxTest: public CvTest
         }
 
         double minVal, maxVal;
-        if (type != CV_8S)
+        Mat src_ = src.reshape(1);
+        if (depth != CV_8S)
         {
             cv::Point minLoc, maxLoc;
-            cv::minMaxLoc(src, &minVal, &maxVal, &minLoc, &maxLoc);
+            cv::minMaxLoc(src_, &minVal, &maxVal, &minLoc, &maxLoc);
         }
         else 
         {
             // OpenCV's minMaxLoc doesn't support CV_8S type 
             minVal = std::numeric_limits<double>::max();
             maxVal = std::numeric_limits<double>::min();
-            for (int i = 0; i < src.rows; ++i)
-                for (int j = 0; j < src.cols; ++j)
+            for (int i = 0; i < src_.rows; ++i)
+                for (int j = 0; j < src_.cols; ++j)
                 {
-                    char val = src.at<char>(i, j);
+                    char val = src_.at<char>(i, j);
                     if (val < minVal) minVal = val;
                     if (val > maxVal) maxVal = val;
                 }