Matlab coder "All inputs must be constant"

Hi,

I tried to generate my code to Mex and to C++ using the Matlab coder.

In my m.file I want to do the following lines:

h = round(a*b + b0);

bw_blobs = imclose((clr_cand)>0,ones(h));

When "a" and "b0" are constants and "b" is variable which change between eatch running.

When i tried to generate the code I got the next error message:

"All inputs must be constant"

how can I solve this error?

Please your advise.

Thanks,

Itai