CurveSnap – Image curve extractor (12,001 views)
download CurveSnap V1.1 (1154)
1 Capture curve from screen – A first example
2 Choose curve by connectivity
3 Copy the data
4 Open existed image – A second example
6 Erase to make curve isolated
7 Choose data points by dragging a rectangle
8 Choose curve by its color
If the desired data curve is colored, then Choose by Color is recommended.
I realise that I should use the word SELECT instead of CHOOSE, after studying the usage.