pub unsafe extern "C" fn im_correl(
ref_: *mut VipsImage,
sec: *mut VipsImage,
xref: c_int,
yref: c_int,
xsec: c_int,
ysec: c_int,
hwindowsize: c_int,
hsearchsize: c_int,
correlation: *mut f64,
x: *mut c_int,
y: *mut c_int,
) -> c_int