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this is a software code for corner extraction

FAST feature detectors in C
---------------------------

The files are valid C and C++ code, and have no special requirements for
compiling, and they do not depend on any libraries. Just compile them along with
the rest of your project. 

With gcc, for extra speed, first compile the code with "-fprofile-arcs" as an
option. Then, run the program and recompile with 
"-fbranch-probabilities -freorder-functions -ftsp-ordering".
This can make a significant improvement in speed.



To use the functions, #include "fast.h"

The corner detectors have the following prototype (where X is 9, 10, 11 or 12):

xy* fast_corner_detect_X(const unsigned char * data, int xsize, int ysize, int threshold, int* numcorners)

Where xy is the following simple struct typedef:

typedef struct 
{
	int x, y;
} xy;


The image is passed in as a block of data and dimensions, and the list of
corners is returned as an array of xy structs, and an integer (numcorners)
with the number of corners returned.  The data can be deallocated with free().
Nonmaximal suppression can be performed with the following function:

xy*  fast_nonmax(const unsigned char* im, int xsize, int ysize, xy* corners, int numcorners, int threshold, int* num_nonmax)