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markummitchell / engauge-digitizer

Extracts data points from images of graphs
GNU General Public License v2.0
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Feature Request: Keystone Image Correction #357

Open bmbeyers opened 5 years ago

bmbeyers commented 5 years ago

Hi Mark,

Love using this software. One issues that I consistently run in to is coming across scanned-in or photographed images of 2D Cartesian plots, and the scanning / photography ends up skewing the plot to look trapezoidal rather than rectangular. A keystone image correction would likely solve this issue, but I'd imagine that a fourth axis point would be required in order to determine the horizontal and vertical keystone effect that would be required. Is this something that you've considered or something that anyone else has brought up in the past?

Thanks!

markummitchell commented 5 years ago

That sounds like a great idea. It will take a while though.

There are 3 and 4 point modes now, but the 4 point mode (accessible by Import Advanced) is only for affine transformations and axes with only one coordinate known at the tics.

gerritnowald commented 2 years ago

A workaround is to do the keystone image correction in GIMP.