flipbytes.c

matlab处理图像的一些基本方法。其中有一部分mex程序需要安装编译

/*
FLIPBYTES.C
        	Cmex function to flip the bytes of a given number or matrix.
		This function is usefull to read and write the Nanoscope
		file in the correct way. 

  The calling syntax is:

			[Q] = flipbytes(R)


  Claudio   October 2, 1994

*/

#include <math.h>
#include "mex.h"

/* Input Arguments */

#define	M_IN	prhs[0]


/* Output Arguments */

#define	M_OUT	plhs[0]



static
void flip(	
	    double pin[],
	    double pout[],
	    int s
	)
{
	unsigned short p;
	short q;
	int i;

	for(i=0; i<s;i++)
	  {
	    p=(short)pin[i];
	    q=p<<8 | p>>8;
       	    pout[i]=(double)q;
	  }

	return;
}

void mexFunction(
	int		nlhs,
	Matrix	*plhs[],
	int		nrhs,
	Matrix	*prhs[]
	)
{
	double	*pin;
	double	*pout;
	unsigned int row,col;

	/* Check for proper number of arguments */

	if (nrhs != 1) {
		mexErrMsgTxt("FLIPBYTES requires one input arguments.");
	} else if (nlhs > 1) {
		mexErrMsgTxt("FLIPBYTES requires one output argument.");
	}


	/* Check the dimensions of M_IN */

	row = mxGetM(M_IN);
	col = mxGetN(M_IN);


	/* Create a matrix for the return argument */

	M_OUT = mxCreateFull(row, col, REAL);


	/* Assign pointers to the various parameters */

	pout = mxGetPr(M_OUT);

	pin  = mxGetPr(M_IN);
      


	/* Do the actual computations in a subroutine */

	flip(pin,pout,row*col);
	return;
}