Trouble tracing bitmaps from pdf's

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Paint Chip
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Trouble tracing bitmaps from pdf's

Post by Paint Chip »

Hi folks, I'm having trouble with the trace bitmap function in inkscape - when I import a pattern in a pdf it shows up in the inkscape window ok, but when I choose trace bitmap it often won't appear in the the trace window after selecting update. After a dozen tries doing the same thing over, then it mysteriously shows up. Went through the help tutorial umptine times but it doesn't seem to work the way they say it should - until it does. When it finally does work, I am not sure what I did differently - nothing, as far as I can tell. Its got me pulling my hair out. What am I doing wrong?
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WyoGreen
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Re: Trouble tracing bitmaps from pdf's

Post by WyoGreen »

Read this:
As easy way to see if your PDF file contains vector or bitmap content is to magnify the drawing to more than 800%. If you see smooth curves and straight lines, it’s a vector file. If what you see on screen looks jagged, ragged or pixelated, it is a bitmap file and you will only be able to create a drawing template to aid in redrawing the file in your engineering application.
Perhaps some of your PDF graphics are bitmaps and thus the trace function works. If your PDF graphic is a vector file, then maybe the trace program won't trace it. It shouldn't need to, as it's already a vector graphic. This is totally off the top of my head, I'm not an Inkscape user.

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Paint Chip
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Re: Trouble tracing bitmaps from pdf's

Post by Paint Chip »

I zoomed in on an object and it definitely is a bitmap. As mentioned in my post - it will finally show up in the trace bit map window after fiddling with it a dozen or more times - just don't know what makes it work/why it won't show up the first time.
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acourtjester
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Re: Trouble tracing bitmaps from pdf's

Post by acourtjester »

Do you have the object selected (arrows and a box around it) if not it will not show in the trace box.
Inkscape needs to know what you are tracing.
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Paint Chip
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Re: Trouble tracing bitmaps from pdf's

Post by Paint Chip »

Yes, it is selected.
Old Iron
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Re: Trouble tracing bitmaps from pdf's

Post by Old Iron »

Post one that doesn't work and one of us will try it in our Inkscape to see if the same issue is present.
Paint Chip
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Re: Trouble tracing bitmaps from pdf's

Post by Paint Chip »

Here is a part I was trying to trace. I did finally get it to show up in the bitmap trace window - but only after a fiddling (selecting, deselecting,
trying different options after right clicking, etc.) with it for 15-20 min (it should have worked in seconds by simply selecting and then choosing trace bitmap) and I don't know why it worked when it finally did.

https://www.dropbox.com/s/9mcpzazizhdk6 ... 2.pdf?dl=0
Old Iron
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Re: Trouble tracing bitmaps from pdf's

Post by Old Iron »

I don't know what it is about this that you want to trace but, this is what was on the link you posted and here it is
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scan2.JPG
Scan.JPG
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Paint Chip
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Re: Trouble tracing bitmaps from pdf's

Post by Paint Chip »

I wanted the outline to feed to the plasma cutter. What did you do to get the trace? As I mentioned in a pervious post, I have been
1.importing the pdf/cropping down to just the object
2.making sure the object was selected
3.selecting trace bitmap from the path menu
4. selecting update
It should appear in the window of the bitmap box at this point but I get nothing, until for some reason it shows up about the time I get ready to give up on it. I just don't know why this being so difficult. If you did the same thing to get this, maybe I should try reinstalling inkscape.
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Re: Trouble tracing bitmaps from pdf's

Post by Old Iron »

Download the PDF, go to the Start Menu, choose Accessories and then click Snipping Tool. Scroll over the part you want, save it as a jpg to where you can find it (I save to Desktop), then right click on it, click on Open With Inkscape and do your work.
Or you can open Inkscape then drag and drop the jpg right off the Desktop.
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Re: Trouble tracing bitmaps from pdf's

Post by Paint Chip »

Ok, that works. Thanks! Still not sure why it doesn't just work the other way though.
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Re: Trouble tracing bitmaps from pdf's

Post by Paint Chip »

OK, after watching numerous you tubes last night on tracing bitmaps, I finally got this figured out. You can directly import the pdf into inkscape. You can use the clipping function to eliminate all but the object or delete the stray nodes later. To get the trace bitmap function to work on the imported object, I had to switch from the Select Objects key to the Edit Nodes function key and then use that cursor to select the object. Once you do this and then select trace bitmap/OK or Update button the object shows up in the trace bitmap window. Worked every time the first time. After all the hair pulling, I'm pretty sure I won't forget that lesson the next time I go to use it.
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Re: Trouble tracing bitmaps from pdf's

Post by acourtjester »

2 Other function that help to remove unwanted objects to get the drawing with what you want it in are the Ungroup under the Object menu. And the Break Apart under the Path menu. They will separate parts of the drawing that you can select and move or remove. I use this many times to compose what I want from a drawing for saving and cutting. I open up a second Inkscape page ( select NEW under file menu) and use the copy and paste to go between pages. In the image you can see the parts of the drawing as ungrouped, I selected the outline and moved it away.
You can group parts by selecting one part and hold down the shift key and select others, then group them to move or remove.
sometime using group and ungroup works and other time break apart and combine (under path menu) works.
ungrouped.jpg
Selected group.jpg
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selected group moved.jpg
selected group moved.jpg (16.07 KiB) Viewed 1709 times
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