how to use "imresize" in mex file

Hi guys

I have wrote the following code to use "imresize" function in mex file.

void mexFunction(int nlhs, mxArray *plhs[], int nrhs, mxArray *prhs[])
 {
     mxArray *output[1];
     mxArray *input[3];

     input[0] = prhs[0];
     input[1] = mxCreateDoubleMatrix(1, 1, mxCOMPLEX);
     double *x = mxGetPr(input[1]);
     x[0] = 0.5;

     //double *p = mxGetPr(input[1]);
     //mexPrintf("%f\n", p[0]);
     input[2] = mxCreateString("bilinear");

     mexCallMATLAB(0, NULL, 1, &prhs[0], "imshow");
     mexCallMATLAB(1, output, 3, input, "imresize");
     mexCallMATLAB(0, NULL, 1, &output[0], "imshow");  
}

But it always gives me the error "Function IMRESIZE expected its second input, SCALE, to be nonzero." Actually, I use "mexPrintf" to print the content of input[1]. It's 0.5. Can anyone tell me what does happen?

Thanks,

Zhong

Answer 1

[zhang]

This problem is kind of solved.

I use

     input[1]=mxCreateDoubleScalar(0.5);

to replace

    input[1] = mxCreateDoubleMatrix(1, 1, mxCOMPLEX);
    double *x = mxGetPr(input[1]);
    x[0] = 0.5;

And the it works.