plot with image and set arrow

Hello all.

I need help for the following problem, anyone know the solution plz help.

Line 1 and 2 below show an excerpt from my gnuplot file

1. set arrow from x1,y1 to x2,y2 nohead lw 0
2. plot "file.txt" with image

What I try do to is to plot an image based on data from "file.txt" (line 2).
In this image I want to draw a line from x1,y1 to x2,y2 (line 1). The problem
is that the line draw is hidden behind the image drawn in line 2. Even though
I change the order of line 1 and 2, the same problem occurs.
Anyone know the solution plz help?

Thanks for your time

vph