How do I convert the following image graph into data (if possible into function)?

enter image description here

I checked this answer and found that my problem is grid and plot have same color.

  • 1
    $\begingroup$ what about: 3831 $\endgroup$
    – Kuba
    Feb 1, 2016 at 7:18
  • $\begingroup$ @Kuba thank you i'll check it out. $\endgroup$
    – S L
    Feb 1, 2016 at 7:19
  • $\begingroup$ Here is a solution that might work for you: mathematica.stackexchange.com/a/167483/55694 $\endgroup$
    – Vixillator
    Mar 8, 2018 at 23:17
  • $\begingroup$ Maybe you should try plotdigitizer. You can eliminate the grid lines by masking the curve. $\endgroup$
    – Anonymous
    Apr 9, 2021 at 12:29

1 Answer 1


If the problem is only to remove the grid, that's relatively easy. You just remove everything but the grid, then take the difference.

You can use Closing with a rectangular structuring element to remove everything but the horizontal / vertical grid lines, like this:

img = Import["https://i.stack.imgur.com/TkvSR.png"];    
hFilter = Closing[img, BoxMatrix[{10, 0}]];
vFilter = Closing[img, BoxMatrix[{0, 10}]];

then take the pixel-wise min to get the full grid:

grid = ImageApply[Min, {hFilter, vFilter}];

enter image description here

Then simply binarize the difference:

Binarize[ImageDifference[img, grid]]

enter image description here

(From here, you should be able to use code from the answers already linked.)


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