tracing bitmaps

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jmckee
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tracing bitmaps

Post by jmckee »

I have a plan for a baby cradle that I scanned on the big scanner at Kinkos. I want to cut the pieces out on the CNC.
I imported the TIF files from the scans into Aspire using the Import Bitmap for Tracing function, and then traced the bitmap. It seems like the editing of the tracing is taking a long time (hours). The lines that were drawn in the tracing process aren't nice and smooth. They are jagged and broken, requiring me to do a LOT of node editing.
Is this normal operating procedure for large pieces that are traced like this? Some of these pieces are going to be 33" long, so this is not a toy, it is a full size cradle. I have spent several hours today and am still not finished.
Is there a better way to do this? This was scanned a few years ago, so I don't remember the resolution of the files. When looking at them on the computer screen, they look pretty good. I do know it was the best we could scan at the time.
Any ideas or tips, or is this normal when tracing bitmaps?
Thank you!

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FixitMike
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Re: tracing bitmaps

Post by FixitMike »

After I trace a bitmap, the first thing I do is use the Fit Curves to Vectors tool with Bezier Curves. This will eliminate a lot of nodes. Then I edit the nodes to smooth the picture. If there is a crevice or spike, I just delete the nodes that are off the smooth line. Faster than trying to move them.
Good judgement comes from experience.
Experience comes from bad judgement.

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ssflyer
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Re: tracing bitmaps

Post by ssflyer »

Tracing a bitmap makes closed vectors around your lines - not what you want for this.
If your original plans have all the dimensions, it's probably easiest to simply recreate it from the dimensions in Aspire.
If you don't have dimensions, then use the drawing tools to recreate the bitmap, manually.
Ron Sloan

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rscrawford
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Re: tracing bitmaps

Post by rscrawford »

You could probably draw the design yourself in a couple hours, and then you know that the dimensions are all exact so the cradle will fit together properly!
Russell Crawford
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martin54
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Re: tracing bitmaps

Post by martin54 »

Well worth the time taken to learn how to use the drawing tools properly, as has already been said you could probably have manually traced this a lot quicker than trying to edit an auto trace.
You would be surprised just how quickly it can be done with a bit of practice.

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