AutoTrace a Background image

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AutoTrace a Background image Pro version only

AutoTracing a raster image is always a challenging task. There isn't here a perfect mathematical single solution for this problem.
We developed a custom feature to help you to Trace in an automatic or semiautomatic way a Raster image.

A note: we define here as Tracing the conversion of a line/curve of black pixels in a Cad element, like a Polyline, closed Polyline, Circle, Arc, Ellipse, Spline, Closed Spline

As first of course you must add a background raster image to your Drawing. See How to insert a background raster image.
After doing that you will see something similar to the following picture:

Now click the "Draw - AutoTrace a Background image' main menu, and this new dialog window will appear:

Now you must do 2 steps:

Step 1 - Raster preprocessing You must use here the commands included in the first frame to prepare the image to a good Autotracing. See the Raster preprocessing page to have more info and tips.
Step 2 - Tracing elements Now you can use automatic tracing of all elements clicking the 'Trace all elements!' button, or click a point on each of them with the mouse. See the Tracing elements page to have more info and tips.

In this case we need to cut the Gray shape, so we simply will apply the 'Enhance BORDERS' function. Here below the result of this Preprocessing:

As you can see now the raster image has been modified, and just the Borders are rendered in black. Still no traced elements, but a good starting point to get them. The trick is to create thin '1 pixel wide' lines.
Now we can just press the 'Trace all elements!' button and the most is done, see the picture below:

As you can see now the Traced element list is filled, and you can see the Red traced lines.
Adjusting the zoom and the viewing settings we can also take a deeper look at the result, see the picture above with:

In Gray the old raster image
In Red the Traced elements
As Green Dots the vertices of the traced elements

Now you can simply the 'OK' button and all the Traced elements will be inserted in your Drawing.

Before going on we suggest you to take more confidence with the 2 basic steps:

Pro version only