why 'load_image' function could n't be used in matlab?

I was trying to process some images in matlab by using linear color space image feature of ipt. For this, I followed a tutorial of MAtLAB central

( http://www.mathworks.com/matlabcentral/fileexchange/9554-a-numerical-tour-of-signal-processing/content/numerical-tour/multidim_color/index.html).

When I was using the following command according to this tutorial an error message was encountered ??? Undefined function or method 'load_image' for input arguments of type 'struct'.

   M='3.BMP';
  >> n=256;
  >> options.nbdims = 3;
  >> N = load_image(M,n,options);

Is it due to the mismatching of image type or there is some other reasons? Any suggestion?

Thanks

[Walter Roberson]

Perhaps you did not follow the steps for adding the routines to your MATLAB path ?

You could try

which -all load_image

to see if it knows about a load_image at all.