Digitize a graph automatically

Hi

I have some paper graphs and need to extract data in (x, y) format. I scan all graphs to convert them in *.png file format. My problem is extract data from *.png files.

I search and find some codes, but they ask me to click over graph line manually. I need a practical code to do that automatically.

I google about my problem and find a website which extract data automatically. I test website with attached "chart1.png" file and set parameters as "SetParameters.png". It works perfectly.

I'm looking for a solution in MATLAB to extract data from my *.png files. Please help me to solve my problem.

Thanks a lot

Mani

[Walter Roberson]

Did you look at the over 20 File Exchange contributions?

https://www.mathworks.com/matlabcentral/fileexchange/?utf8=%E2%9C%93&term=tag%3Adigitize

[Mani Ahmadian]

Dear Walter

I test this sample codes, all of them have a common point in digitize process; user should pick some points in graph manually. I need a code which can pick points automatically by use of image processing.

Thanks a lot

Mani

[Walter Roberson]

I am certain that there is no "practical" code that can handle all of the various cases automatically. Possibly there might be practical code for one particular kind of graph, especially if it is all generated by the same software.