extract data from graph ?

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extract data from graph ?

CdeMills
Hello,

I need to correct a paper containing graphs saved as bitmap images. Those
images were generated by a scope, and I can't redo the experiment. Is there
some way to "undo" the graph and get back the curves ?
I can take the image, apply a differentiator, check for regions of high
contrast, and map that region back to values. But if some automatic tool
could do it quickly and without error, it would be better.

Regards

Pascal



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Re: extract data from graph ?

tmacchant
--- Pascal.Dupuis

> Hello,
>
> I need to correct a paper containing graphs saved as bitmap images. Those
> images were generated by a scope, and I can't redo the experiment. Is there
> some way to "undo" the graph and get back the curves ?
> I can take the image, apply a differentiator, check for regions of high
> contrast, and map that region back to values. But if some automatic tool
> could do it quickly and without error, it would be better.
>
> Regards
>
> Pascal

l found the below:

https://automeris.io/WebPlotDigitizer/

Tatsuro


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Re: extract data from graph ?

Przemek Klosowski-7
In reply to this post by CdeMills
On 03/28/2018 09:07 AM, CdeMills wrote:
> Hello,
>
> I need to correct a paper containing graphs saved as bitmap images. Those
> images were generated by a scope, and I can't redo the experiment. Is there
> some way to "undo" the graph and get back the curves ?
> I can take the image, apply a differentiator, check for regions of high
> contrast, and map that region back to values. But if some automatic tool
> could do it quickly and without error, it would be better.
There's Engauge http://markummitchell.github.io/engauge-digitizer/
as well as some excellent web based ones (Tatsuro's email)



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RE: extract data from graph ?

Allen.Windhorn-3
In reply to this post by CdeMills
Pascal,

> -----Original Message-----
> From: Help-octave [mailto:help-octave-
>
> I need to correct a paper containing graphs saved as bitmap images. Those
> images were generated by a scope, and I can't redo the experiment. Is there
> some way to "undo" the graph and get back the curves ?
> I can take the image, apply a differentiator, check for regions of high
> contrast, and map that region back to values. But if some automatic tool
> could do it quickly and without error, it would be better.

Take a look at Datathief, it works pretty well once you get the
hang of it, and it's free to try out at least.  Datathief.org

Regards,
Allen


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Re: extract data from graph ?

Dr.-Ing. Dieter Jurzitza
In reply to this post by Przemek Klosowski-7

Hello CdeMills,

on top of all the suggestions you might consider "PlotDigitzer". It is java based and runs on every operating system; it is specifically suited for x-y data and allows you to enter both a x and a y - scaling before determining the values from the bitmap graphs.

You get scaled values as x-y ascii data - I like it much and have used it very often until now.

Hope this helps,

regards

 

Dieter

Am Mittwoch, 28. März 2018, 15:51:12 CEST schrieb Przemek Klosowski:

> On 03/28/2018 09:07 AM, CdeMills wrote:

> > Hello,

> >

> > I need to correct a paper containing graphs saved as bitmap images. Those

> > images were generated by a scope, and I can't redo the experiment. Is

> > there

> > some way to "undo" the graph and get back the curves ?

> > I can take the image, apply a differentiator, check for regions of high

> > contrast, and map that region back to values. But if some automatic tool

> > could do it quickly and without error, it would be better.

>

> There's Engauge http://markummitchell.github.io/engauge-digitizer/

> as well as some excellent web based ones (Tatsuro's email)

 

 

--

-----------------------------------------------------------

Dr.-Ing. Dieter Jurzitza 76131 Karlsruhe

 



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Re: extract data from graph ?

Francesco Potortì
In reply to this post by CdeMills
>I need to correct a paper containing graphs saved as bitmap images. Those
>images were generated by a scope, and I can't redo the experiment. Is there
>some way to "undo" the graph and get back the curves ?

Use g3data to retrieve point coordinates from a graph.

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ISTI - Area della ricerca CNR          Mobile: +39.348.8283.107
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Re: extract data from graph ?

Alexander Semke
In reply to this post by CdeMills

On 28.03.2018 15:07, CdeMills wrote:
> Hello,
>
> I need to correct a paper containing graphs saved as bitmap images. Those
> images were generated by a scope, and I can't redo the experiment. Is there
> some way to "undo" the graph and get back the curves ?
> I can take the image, apply a differentiator, check for regions of high
> contrast, and map that region back to values. But if some automatic tool
> could do it quickly and without error, it would be better.
Maybe you want to check out LabPlot. We added this feature two years ago
to LabPlot:
https://labplot.kde.org/2016/03/29/labplot-2-2-0-released/

--
Alexander


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Re: extract data from graph ?

CdeMills
Hello,

I was a few days on displacement.

What a great list ! Thanks to everyone who responded.

I worked with engauge. Great job. The original data were quite noisy, it
made a good job of low-pass filtering the curves.

Regards

Pascal



--
Sent from: http://octave.1599824.n4.nabble.com/Octave-General-f1599825.html


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Re: extract data from graph ?

nrjank
On Wed, Apr 4, 2018 at 3:22 AM, CdeMills <[hidden email]> wrote:
> Hello,
>
> I was a few days on displacement.
>
> What a great list ! Thanks to everyone who responded.
>
> I worked with engauge. Great job. The original data were quite noisy, it
> made a good job of low-pass filtering the curves.
>

replying for posterity:

Some of this is out of date, but one list of data digitizers:
http://www.ccp14.ac.uk/solution/hardcopy2data.htm

Also, xyscan is GPLv3 tool:
http://rhig.physics.yale.edu/~ullrich/software/xyscan/

Datamelt (used to be SCaViS) will supposedly let you do this and more:
http://en.wikipedia.org/wiki/DataMelt

and I'm a fan of WebPlotDigitizer, an HTML5 tool with both a web-based
and a standalone, open source (AGPLv3) version:
https://automeris.io/WebPlotDigitizer/

a fan because as long as i can remember the name/website i don't have
to install anything