How to call imresize in mex file (MATLAB)

Question

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

  #include "mex.h" 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"); } 

This gives an error: Function IMRESIZE expected its second input, SCALE, to be nonzero. How can I fix it?

Answer 1

So just try replacing the following code:

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

with this line

  input[1]=mxCreateDoubleScalar(0.5);