How to read the data point from a image?

The data in the literature is always important, and worth reuse. How to get the data if I only have image file, eg jpg, bmp, png, etc. A image example is attached in this question.

Thanks

Q.Q.

Answer 1

[Walter Roberson]

In no particular order, and probably not complete:

http://www.mathworks.com/matlabcentral/fileexchange/30418-graphscannergui

http://www.mathworks.com/matlabcentral/fileexchange/7173-grabit

http://www.mathworks.com/matlabcentral/fileexchange/23317-graph-digitzer

http://www.mathworks.com/matlabcentral/fileexchange/33122-readdata

http://www.mathworks.com/matlabcentral/fileexchange/928-digitize2-m

http://www.mathworks.com/matlabcentral/fileexchange/36904-matlab-script-for-digitizing-a-published-graph

http://www.mathworks.com/matlabcentral/fileexchange/11077-figure-digitizer

http://www.mathworks.com/matlabcentral/fileexchange/49009-image-digitizer

http://www.mathworks.com/matlabcentral/fileexchange/287-digitize-m

http://www.mathworks.com/matlabcentral/fileexchange/27884-manually-digitize-scanned-chart

[Matthias]

https://www.mathworks.com/matlabcentral/fileexchange/928-digitize2-m

was once a pick of the week and worked well for me.

However, I had to change line 273 from

if (writefname == 0) | (writepname == 0),

into

if sum(writefname == 0) || sum(writepname == 0),

to work properly.