WebPlotDigitizer - WebPlotDigitizer - Web based tool to extract numerical data from plots, images and maps.
DigitizeIt - Sometimes it is necessary to extract data values from graphs, e.g.
Engauge Digitizer - This open source, digitizing software converts an image file showing a graph or map, into numbers.
GraphClick - GraphClick is a graph digitizer shareware for Mac OS X which allows to automatically retrieve the original (x,y)-data from the image of a scanned graphor fom QuickTime movies.
im2graph - im2graph graph digitizing software to convert graphs to numbers
g3data - g3data is used for extracting data from graphs.