Hello,

I have an image of a 2D plot (data of y versus x) copied from a PDF file and stored in TIFF format. I used some simple image manipulation to read the scales of the axes (in pixels), define some scale transformations, and read the numbers in the graph. That worked fine and now I have a rather long list (~ 60K) of x-y data points.

Now I want to overlay the original image and a ListPlot of the data. I can make the original image semitransparent with SetAlphaChannel and adjust its size with ImageResize, but I have difficulties controlling the relative sizing and aligning of the image and the ListPlot, so as to get the axes to match exactly (I am OK with adjusting the parameters by trial and error).

I have tried Overlay, Prolog, Epilog, Inset, ImageCompose, but there is always some part of the sizing or aligning that does not respond as expected. There is obviously something I am missing. I have done this in Excel before, and it was not very hard (but it is hard with 60K data points).

Any ideas will be greatly appreciated.

OL.