Trace a Template from Photo using Inkscape

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Note - this is in response to a question asked by Hank DeVeau at the Plasmacam Owner's Community Online Forum, but which I thought may be useful to others here as well.

IMG_1132.jpg

"This is a picture of a paper template, cut to size, a customer has brought me to be cut from steel. I have drawn reference points on it hoping that when converted I can use them for scaling.(36" between points) Can this be converted with ink scape and if so how do i do it? It would be too easy for you to do it for me but I have another one similar to this and there is a possibility of more to come so it is probably a good idea to get this figured out!!
Thanks in advance for all your help."

"Oh yeah, I tried to do it in DE but it comes out too dirty"

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Hank - you are correct that your photo does not lend itself to an auto trace - either with Design Edge which you tried, or with Inkscape - as there is not enough contrast between the actual template and background.

Here is a tip: paint your template flat black and place over a white background before you take your photo. Then you can use either Design Edge or Inkscape to achieve a high quality auto trace providing you with the dxf file you are after.

Here is how I would do the manual trace using Inkscape.

photo to dxf 1.jpg

photo to dxf 2.jpg

photo to dxf 3.jpg

photo to dxf 4.jpg

photo to dxf 5.jpg

photo to dxf 6.jpg

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photo to dxf 7.jpg

Hank - after you save your manual trace as a dxf from Inkscape, you can it into Design Edge and draw a dimension between the two circles, then scale such that the final dimension is the 36" you are after.

If you wish to scale it first in Inkscape, here is how to do it.

David

scale 1.jpg

scale 2.jpg

scale 3.jpg

scale 4.jpg

scale 5.jpg

scale 6.jpg

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scale 8.jpg

[adbuch]

Hank - as mentioned above if you spray paint your template flat black and place on top of a white background before taking your photo, this will make it very simple and quick to do an Auto Trace using Inkscape (or Design Edge).

Here is the process to do the auto trace and scaling to size using Inkscape.

David

Photo of template painted black with contrasting white background.

template painted black with white background 1.jpg

Process of importing, auto tracing, and scaling to size using Inkscape.

template painted black with white background 2.jpg

template painted black with white background 3.jpg

template painted black with white background 4.jpg

template painted black with white background 5.jpg

[plasmanewbie]

Very nice tutorial David. How you do the straight line and then pull it into the curve is a technique I use all the time in Corel. Works like a charm unless you need precise rads. This would be a great topic for the Inkscape forum, maybe ADMIN can move it or copy it there.

[adbuch]

Thanks! I have already posted a link to it there. No need to move it as this is also an excellent topic for the "File Conversion Help Wanted" section of the forum.

David

viewtopic.php?f=77&p=226723#p226723

[plasmanewbie]

Awesome, and I agree

[acourtjester]

David Very nice tutorial, the combined knowledge base of PS is always growing. Question asked, answer given, screen shots big plus.

[adbuch]

Thanks guys! The dimensioning and scaling is certainly more cumbersome with Inkscape than some of the other programs, but doable nonetheless.

David

[34by151]

My go to is Lightburn simple and easy. Camera mounted above the table and calibrated. Then its as simple as pressing camera/trace

[adbuch]

My go to is Lightburn simple and easy. Camera mounted above the table and calibrated. Then its as simple as pressing camera/trace

Thanks for posting! The LightBurn Camera Trace will work well for drawings, etc. with high contrast between the drawing and/or template and the background - as the one shown in this demo video.

https://www.youtube.com/watch?v=1w1m-Dn9MmU

camera trace.jpg

But for images such as the one supplied by Hank at the beginning of this post, a manual trace will usually be necessary for satisfactory results.

David

camera trace 1.jpg

camera trace 2.jpg

camera trace 3.jpg

[34by151]

I use the camera to trace physical parts, just thought I'd add that into the mix

[sonbakler]

I use the camera to trace physical parts, just thought I'd add that into the mix

I too have used a camera in the past and it works well for parts that are too big to scan on my all in one printer. I just found the curved camera lens tends to distort the image so I prefer the scanner if I can use it.

[adbuch]

I use the camera to trace physical parts, just thought I'd add that into the mix

Thanks 34by151! You input is appreciated. For larger solid objects or large templates, I also like to use Scanything/camera combo on my cnc router table, or my Calcomp digitizing tablet with the LogicTrace software. But for smaller items I find it very convenient to take a photo and manually trace with Inkscape.

David