Hi,
Usually, data are given by a chart in picture form, such as JPG,TIF,BMP,PNG... and not all the points in picture are useful value.
Like below, it is the V-I charactristic of a diode.
I want to get the V and corresponding I value, then I can get a fit function V(I) (or I(V) ).
Although,we can read several more exact points by eye-measurement, and get a fit function, i think the fit function will be less precise if we read more points.
How can I do to extract as much points as possible? Any help will be appriciated