Inkscape

How to onvert pdf objects to vector objects sin a pdf file

Asked by Kevin

I have scanned a drawing into pdf format. The drawing contains several objects eg. gears. Is there a way I can take this pdf file and convert the objects in this file into vectors so I can use the power of Inkscape?

I need the objects in vector format so they can be manipulated and converted into another pdf file which can be sent to a laser cutter.

Thank you for any help you can provide.

Kevin Chadwick

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Hachmann
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Best Hachmann (marenhachmann) said : 		#1

Hi Kevin,

yes, there is a way to do this (two, actually).
As the pdf file you have seems to contain a raster image, you need to vectorize (or trace) the raster image in Inkscape.

To do this, open the pdf with Inkscape, select everything, then ungroup everything until all you have is ony an embedded bitmap image.

Then you've got two options:
- manual tracing (means: draw along the lines in your drawing, using Bezier or Pencil tool) - tedious, but very accurate
- autotracing (select image, use Path -> Trace bitmap), then - quicker, but might still need manual work if result is not as you like it, takes time to learn

A tutorial for the autotracing feature can be found inside Inkscape: Help -> Tutorials -> Tracing
and there is another, more detailed one, in the manual:
http://tavmjong.free.fr/INKSCAPE/MANUAL/html/Trace.html

When you save the file, make sure you save it as svg, and don't overwrite your pdf (info is lost when saving to pdf, and the pdf will be changed, too).

Hope this will get you started,
 kind regards,
 Maren

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Kevin (kevin-chadwick) said : 		#2

Hi Maren, Thank you for your quick and excellent response. I have not yet tried your suggestions but I am sure one of the two will solve my problem. The tutorials will also be of considerable help.

Very many thanks for your assistance. It's people like you that make the Internet so useful.

Best regards,

Kevin Chadwick
Stittsville, Ontario, Canada

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Hachmann (marenhachmann) said : 		#3

Hi Kevin,

answering your mail via "contact this user":

Attachments aren't supported, neither here, nor did I get one in the mail you sent. You'd have to upload the file somewhere else, unfortunately, if you would like us to have a look.

The number of objects in your pdf file will always be 1, if the only thing it contains is a scan (produced directly by the scanner, I guess?) - it is just a pixel (raster) image embedded in a pdf file.

But sometimes, this single image is grouped when you import it, and Inkscape can't trace a group.

What does it say in the status line when you select the image to trace it? (at the bottom of the window)
Does it say 'Group of x objects'? If so, hit Ctrl+U to ungroup (until it says 'Image num x num pixels', then try the vectorization again.
Also make sure that the image is selected. Sometimes, one accidentally deselects an object, and wonders why things don't work :) - happened to me a lot of times! Always keep an eye on the status line.

You might not even see the difference directly after vectorization, because the new paths will lie exactly above the original raster image. Click on them with the mouse and drag them away from their original position.

Hope this helps,
 kind regards,
 Maren

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Hachmann (marenhachmann) said : 		#4

Answering the second mail:

this confirms my suspicion - by double-clicking on a group, you 'enter' it, and can access the single objects inside it.

Happy crafting!

Maren