GRASS GIS 7 Programmer's Manual
7.9.dev(2021)e5379bbd7

Zero Crossing functions. More...
#include <stdio.h>
#include <math.h>
Go to the source code of this file.
Macros  
#define  TINY 1.0e3 
Functions  
int  G_math_findzc (double conv[], int size, double zc[], double thresh, int num_orients) 
Finds locations and orientations of zero crossings. More...  
Zero Crossing functions.
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Definition in file findzc.c.
#define TINY 1.0e3 
Definition at line 32 of file findzc.c.
Referenced by G_math_findzc().
int G_math_findzc  (  double  conv[], 
int  size,  
double  zc[],  
double  thresh,  
int  num_orients  
) 
Finds locations and orientations of zero crossings.
Finds the locations and orientations of zero crossings in the input array conv, which is the result of the convolution of the MarrHildreth operator with the image. The output array is zc, which is nonzero only at zero crossing pixels. At those pixels, the value is 1 + (orientation), where orientation is a value from 0 to num_orients.
[in]  conv  input 
[in]  size  size of largest matrix column or row 
[out]  zc  output 
[in]  thresh  magnitude threshold 
[in]  num_orients 