uchar* cvPtr3D(CvArr* arr, int idx0, int idx1, int idx2, int* type) {
    void *fptr;
    uchar*retval;

    fptr = dlsym(_Chcv_handle, "cvPtr3D_chdl");
    if(fptr == NULL) {
        fprintf(_stderr, "Error: %s(): dlsym(): %s\n", __func__,  dlerror());
        return NULL;
    }
    dlrunfun(fptr, &retval, cvPtr3D, arr, idx0, idx1, idx2, type);
    return retval;
}
