Re: 2d engraving

> --- In CAD_CAM_EDM_DRO@y..., "eforum3001" <eforum@s...> wrote:


> > I hope to use a raster-to-vector conversion sw to convert photos

to

> > gcode for 2d engraving. I have tried wintopo but the face of the
> > subject was not recognisable.

Here is some pointers from the wintopo list:

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For this type of image you need to experiment a bit with the Canny
parameters ("Image->Set Canny's Parameters..." menu option) to get
the best
edge detection.

If you install the WinTopo Pro 2.4 beta version you can experiment
easily
using the Vectorisation options window, which shows an instant
preview while
you change the parameters. (See http://wintopo.com/beta/first.htm for
the
2.4 beta version).

It's hard to get a good result from the Monroe image because it is
quite low
resolution, a little grainy, and has high contrast shadows (which
give false
edges).

In my trials on this image, I found the following settings worked
reasonable
well:
- reducing the Standard Deviation to 3 was best (the edges that
wanted are
blurred over about 3 pixels),
- then setting the High value up to about 40 (to reduce the
graininess) ,
- and leave the low value at 3 (to detect long lines without too many
gaps).

With more experimentation you may find better settings for you
particular
purposes. You will probably still need to do some cleaning up after.

Peter