added special function to patch NaN's in image. call this function from bilateralfilter (should fix bug #1811)

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

@@ -2214,6 +2214,9 @@ CV_EXPORTS_W void magnitude(InputArray x, InputArray y, OutputArray magnitude);
 //! checks that each matrix element is within the specified range.
 CV_EXPORTS_W bool checkRange(InputArray a, bool quiet=true, CV_OUT Point* pos=0,
                             double minVal=-DBL_MAX, double maxVal=DBL_MAX);
+//! converts NaN's to the given number
+CV_EXPORTS_W void patchNaNs(InputOutputArray a, double val=0);
+    
 //! implements generalized matrix product algorithm GEMM from BLAS
 CV_EXPORTS_W void gemm(InputArray src1, InputArray src2, double alpha,
                        InputArray src3, double gamma, OutputArray dst, int flags=0);