pub unsafe extern "C" fn PixelIterateDualRead(
    call_back: PixelIteratorDualReadCallback,
    options: *const PixelIteratorOptions,
    description: *const c_char,
    mutable_data: *mut c_void,
    immutable_data: *const c_void,
    columns: c_ulong,
    rows: c_ulong,
    first_image: *const Image,
    first_x: c_long,
    first_y: c_long,
    second_image: *const Image,
    second_x: c_long,
    second_y: c_long,
    exception: *mut ExceptionInfo
) -> c_uint