"kinor" wrote in message <firstname.lastname@example.org>... > Jan > > you want to insert the points into your image data. plot does the display job.. > > kinor Hi Jan. In case you're having a mask (as far as I can ssee you're working on snakes methods) and you want the edge coordinates you can do it via the contour function or my mask2poly (http://www.mathworks.com/matlabcentral/fileexchange/32112-mask2poly) function. To the issue: in case you're using imshow, you may have to reverse the Y coordinates befor the plot\line command. You should note the X and Y coordinates- those are reversed in plot/line and image axes. A simple flilr, or coordinates hift resolves the issue. If you want to generate an image with the line in it my function addMarkerLines2Img (http://www.mathworks.com/matlabcentral/fileexchange/37427-plot-on-an-image-addmarkerlines2img) can be handy.