Fixed several issues found by static analysis

modules/calib3d/src/calibration.cpp

@@ -1133,6 +1133,7 @@ CV_IMPL void cvFindExtrinsicCameraParams2( const CvMat* objectPoints,
             if( cvDet(&_RR) < 0 )
                 cvScale( &_RRt, &_RRt, -1 );
             sc = cvNorm(&_RR);
+            CV_Assert(fabs(sc) > DBL_EPSILON);
             cvSVD( &_RR, &matW, &matU, &matV, CV_SVD_MODIFY_A + CV_SVD_U_T + CV_SVD_V_T );
             cvGEMM( &matU, &matV, 1, 0, 0, &matR, CV_GEMM_A_T );
             cvScale( &_tt, &_t, cvNorm(&matR)/sc );

modules/calib3d/src/chessboard.cpp

@@ -164,7 +164,9 @@ cv::Mat findHomography1D(cv::InputArray _src,cv::InputArray _dst)
     Mat H = dst_T.inv()*Mat(H_, false)*src_T;
 
     // enforce frobeniusnorm of one
-    double scale = 1.0/cv::norm(H);
+    double scale = cv::norm(H);
+    CV_Assert(fabs(scale) > DBL_EPSILON);
+    scale = 1.0 / scale;
     return H*scale;
 }
 void polyfit(const Mat& src_x, const Mat& src_y, Mat& dst, int order)

modules/core/include/opencv2/core/cvdef.h

@@ -654,7 +654,7 @@ class float16_t
 public:
 #if CV_FP16_TYPE
 
-    float16_t() {}
+    float16_t() : h(0) {}
     explicit float16_t(float x) { h = (__fp16)x; }
     operator float() const { return (float)h; }
     static float16_t fromBits(ushort w)
@@ -681,7 +681,7 @@ protected:
     __fp16 h;
 
 #else
-    float16_t() {}
+    float16_t() : w(0) {}
     explicit float16_t(float x)
     {
     #if CV_AVX2

modules/dnn/src/layers/pooling_layer.cpp

@@ -332,7 +332,8 @@ public:
         int poolingType;
         float spatialScale;
 
-        PoolingInvoker() : src(0), rois(0), dst(0), mask(0), avePoolPaddedArea(false), nstripes(0),
+        PoolingInvoker() : src(0), rois(0), dst(0), mask(0), pad_l(0), pad_t(0), pad_r(0), pad_b(0),
+                           avePoolPaddedArea(false), nstripes(0),
                            computeMaxIdx(0), poolingType(MAX), spatialScale(0) {}
 
         static void run(const Mat& src, const Mat& rois, Mat& dst, Mat& mask, Size kernel,

modules/imgcodecs/src/grfmt_pfm.cpp

@@ -79,7 +79,7 @@ PFMDecoder::~PFMDecoder()
 {
 }
 
-PFMDecoder::PFMDecoder()
+PFMDecoder::PFMDecoder() : m_scale_factor(0), m_swap_byte_order(false)
 {
   m_strm.close();
 }

modules/imgproc/src/contours.cpp

@@ -1532,6 +1532,7 @@ icvFindContoursInInterval( const CvArr* src,
     tmp_prev->link = 0;
 
     // First line. None of runs is binded
+    tmp.pt.x = 0;
     tmp.pt.y = 0;
     CV_WRITE_SEQ_ELEM( tmp, writer );
     upper_line = (CvLinkedRunPoint*)CV_GET_WRITTEN_ELEM( writer );

modules/objdetect/src/hog.cpp

@@ -240,6 +240,7 @@ void HOGDescriptor::computeGradient(InputArray _img, InputOutputArray _grad, Inp
     CV_INSTRUMENT_REGION();
 
     Mat img = _img.getMat();
+    CV_Assert(!img.empty());
     CV_Assert( img.type() == CV_8U || img.type() == CV_8UC3 );
 
     Size gradsize(img.cols + paddingTL.width + paddingBR.width,