fusing an quiver with a contour

Tried to fuse two images - a contour and a quiver plot. Didn't work. Thoughts

C = contour(filteredreducedSection);
[Gx, Gy] = imgradientxy(uint8(filteredreducedSection), 'CentralDifference');
Gx = flipud(Gx);
Q = quiver(Gy,Gx,4);
END = imfuse(Q,C);
figure (5);
imshow (END);