JPG to CAD

[mikegr]

Anyone knows how to convert a jpg file to Corel or cad so it can obtain lines for processing? Need this to send to the laser cutting shop.

[Egilman]

There is no way to directly and automatically convert a JPG file, (raster based) to a Corel file or any vector based file for that matter.....

 

The best option is to load the jpg file into corel as a background and trace it into a seperate vector file then export it to a format the laser cutter can read....

 

There are two advantages to this, it will be straight and accurate and you can scale it....

[DavidG]

there are several ways to do this, software like Adobe Illustrator can certainly do that. Much depends on the quality of your image, and probably you will have to adjust it manually after the conversion. I think Adobe provides a trial period, which might be just fine for your needs. But if you make a search to "jpg to vector" you find several videos on youtube and other solutions, like vectormagic.com and similar.

[mikegr]

1 hour ago, DavidG said:

there are several ways to do this, software like Adobe Illustrator can certainly do that. Much depends on the quality of your image, and probably you will have to adjust it manually after the conversion. I think Adobe provides a trial period, which might be just fine for your needs. But if you make a search to "jpg to vector" you find several videos on youtube and other solutions, like vectormagic.com and similar.

So basically jpg to vector is the suitable search?

[mtaylor]

10 hours ago, mikegr said:

So basically jpg to vector is the suitable search?

That would be a good place to start.  You might need to filter it down to get rid of "clutter" such as adding some keywords line "how can I convert".    

[bigpetr]

As already said, I would recomend to trace it by hand. To adjust automaticly converted  curves to be useful, precise and suitable for lasercuter is usualy more work than to do it by hand. I did it many times.

[AON]

you might try this

 

https://anyconv.com/jpg-to-dwg-converter/

 

I've not used it and have no idea if it is any good

Maybe you can post a review?

[mtaylor]

The one problem I've seen with converting JPG to any CAD is that number of pixels can really mess things up.  The CAD (depending on the program/application) won't necessarily connect the dots as such.   Far less stress just pull the JPG into CAD and then manually trace.

[druxey]

It's a bit of a chore if the image is complex, but Mark and others are correct: import and trace.

[Egilman]

I've tried them all.....  But, the anyconv.com is one I haven't seen just yet....

 

For an example this is one of the drawings I want to convert.....

 

None of the converters have worked this is a standard two color jpg 30x42 E1 sized paper.... it is the lightning mast from the top of a Saturn V LUT 300dpi.....

 

If a converter can't handle this simple drawing then it won't work... I've also tried it on drawings that I've cleaned up from US Navy Booklets of General Plans, they don't work there either

 

There is a process for doing this in cad..... I believe it is posted right here in the site..... Lemme check...

 

Yes by Rex Boocock.... https://thenrg.org/articles/creating-new-ship-drawings (downloadable as a PDF as well)

Then there is this by Wayne Kempson.... https://thenrg.org/resources/Documents/articles/DraftingShipPlansInCAD.pdf

 

Excellent treatises on how to do it....

 

That's the methods I use...

 

EG

 

 

Edited November 7, 2020 by Egilman

[Egilman]

Ok I just tried anyconv.com on the NASA image I posted above of the LUT Lightning Mast....

The input filename....

75M-05128-Sh2.jpg

 

The output filename....

AnyConv.com__75M-05128-Sh2.dwg

 

Took all of about 20 seconds for the conversion and getting a download link.....

 

Tried to load in Autocad 2021.....

This is what I get....

 

It doesn't output valid autocad files...

 

only one test on a very simple drawing, but it pretty much the same on all such sites for serious technical drawings...

 

[geoffs]

Have a look at Inkscape. It has functions to convert from bitmaps/images to vectors.

It's open source software and well supported

[Egilman]

2 hours ago, geoffs said:

Have a look at Inkscape. It has functions to convert from bitmaps/images to vectors.

It's open source software and well supported

Inkscape does it about as well as Corel does which isn't very well at all....

 

But there is a solution out there.... pricey and huge learning curve, but it's designed to convert scanned drawings to vector drawings.... and it is integrated with autocad...

 

Autodesk's Raster Design.....

 

Check it out, designed specifically for those engineering offices that have tons and tons of paper drawings that they need to bring into the digital age.... 

 

It does take a while to figure out how to use it.... I found that it is just easier and faster to just simply trace over the drawing.....

Get you where you want to be a heck of a lot faster.....

 

EG

Edited November 7, 2020 by Egilman

[wefalck]

mikegr, what kind of jpg-image is this about ?

 

Some laser-cutters actually work with pixel-graphics. They process the image line by line and switch on the laser, when they encounter a black pixel and switch it off, when they meet a white pixel. So you may not need to do the conversion after all.

[Trussben]

Import into a CAD program using "insert raster image", trace the lines, splines etc, then delete the image and check if everything looks good before saving as a .dxf file which a CAM software can then open.

[Nirvana]

There's no short cut to go when it comes to convert jpg to dwg/dfx.

I tried Inkscape, gave up.

Using Fusion360, importing any picture for tracing to create a file that can be converted to dwg.

As stated above jpg's is a pixelated picture where it's hard to find the perfect center in a line. When zooming in you will experience fuzziness which will make it even harder.

That being said, if you try to make laser parts you will find it will extremely difficult to make it accurate. Because a draft line on a picture doesn't relate to the fine laser cutting.

I.e on a drawing the line might be .7 mm, which is very coarse for a laser.

[Dr PR]

I have used several bitmap to vector converters, but not recently. Some of the CAD programs I have used have built-in raster to vector converters. Adobe used to have a stand-alone converter long ago but I'm not sure about the name (Streamline?). None of them have worked very well.

 

As mentioned above, bitmap lines have non-zero thickness and vector lines are zero thickness (but they may be displayed with a variety of thicknesses). If the bitmap line is not always the same number of pixels wide - and they rarely are -  the converter may have trouble guessing the line center and generate a bunch of slightly zig-zag segments instead of a single straight line. Curves become a series of short segments instead of a smooth curve.

 

Another problem is the way the converters deal with intersecting lines. Many use algorithms that fail to see across intersections to create a continuous line. Instead, at the intersection they switch from the original line to the crossing line. So at an "X" you get two ">" and "<" lines instead of "/" and "\". The result is really bizarre convoluted lines.

 

The result can be extremely large files with huge numbers of short line segments.

 

I agree that it is usually better to just hand trace the drawing. However, the bitmap to vector conversions are not totally useless. You can put the converted drawing on one layer and lock the layer. Then on other layers you can trace it quickly just by snapping to points on the converted drawing. This is a LOT faster than trying to draw over the bitmap image. It isn't perfect though. You will have to go back and make some corrections, especially to get parallel lines actually parallel.

Edited November 22, 2020 by Dr PR

[bigpetr]

As stated - no shortcuts here. Especialy if you want something precise and suitable for manufacturing based on these plans.

 

Converters are good for graphic designers who needs fast results for their art. Unfortunately It is not one-click solution for industrial/manufacturing purposes, where converted files can only serve as starting point that needs to be heavily modyfied to meet the manufacturing demands. And so it is usualy better and easier to start from scratch. One time I did this work on regular basis so believe me I tried all tools I can get my hands on to simplify this task

[sozdil]

There is a GOOD software for this purpose. Name is SCAN2CAD, you can vectorize any raster or PDF. If your PDF is already a Vector drawing, you can translate into DWG, DXF or some other which I cannot remember. If you have non non-vector PDF or a raster, it also converts the lines into vectors, like lines, curves, splines etc, it can also recognize dotted lines, hatches etc. From a raster or non-vector PDF, the scan has to be clean and good. I cannot describe what is clean and/or good here, you have to try and find out. Before conversion you have to perform several operations on the image like converting to black/white (no grey scale), cleaning speckles and holes, thinning or thickening lines, smoothing the pixels, etc etc. I am not using it for the last 7 or 8 years because it is expensive, but I have made a lot of succesfull conversions.

 

Attached you will find a ship plan page found from internet and its conversion as DXF. The attached conversion is without any correction. You have to clean and correct some shapes, you can do this also on SCAN2CAD with vector superposed on raster. Some part of DXF is removed for copyright purposes. 

 

I cannot remember exatly but you can download and use a trial version for one or two weeks with full functions.4.dxf delete.dxf

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