Trace Image Trick (or self-delusion?)

Community Laser Talk
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When I have a small (e.g. 60 x 100 mm) black and white, clip art, GIF-type image, I greatly increase the dimensions (e.g. 2000 x 3333 mm) before doing a TRACE IMAGE, and then I resize the traced image back to a reasonable size for a project that fits on the bed of my OMTECH.

Perhaps I am deluding myself (if that is the case, I expect I will get straightened out in this forum), but it seems to me that I get a finer resolution image when I reduce the size back to the original than if I had done a trace image on the smaller size.

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Look at it from the other end. What if you did a trace on a postage stamp? Would it pick up the microscopic detail needed for a larger image? I do not know if you need to go that large, but i am sure Trace can do a better job on a larger image.

By the way, thanks for the tip. I never thought about trying this.

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In general, it depends on how the image is resized. Sometime, you can get an aliased image, where each pixel is represented by a square. Not good for tracing… :slightly_smiling_face:
But now, the softwares tend to anti-alias the enlarged image (various algorithms, eg. in Gimp), so you get fuzzy borders. Then the trace process can take the average luminosity of these borders to make lines, therefore it is indeed better than tracing the small image.

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Increasing resolution in a graphics prog also helps a bit.

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LightBurn traces the image in the original resolution of whatever image you loaded. If you resized outside of LightBurn, in another application, imported that image, and traced it, yes, you might feasibly get additional details.

If you just scale up the image in LightBurn, trace it, and scale it back down, the results are identical to what you’d get if you just traced it before scaling up.

This is two traces of a random image overlaid onto each other, the blue one was done at 10x scale (they’re identical):

image
image1009Ă—756 141 KB

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Indeed, image resizing in LB seems to be of the first kind I described, enlarging the pixels:

image
image1745Ă—877 9.62 KB

So transforming this to vector won’t do much good, whatever the size.

I have resized it 8 times bigger (on width, proportional), using the various resize modes of Gimp: none (same as LB), linear (very fuzzy), cubic (OK), NoHalo and LoHalo. The last threes are quite close, but slightly different in contrast and fuzziness.

image
image1037Ă—1104 110 KB

I traced them with the default settings, you can see the results differ:

image
image999Ă—1082 107 KB

Of course, the result will depend on the source image, here I chose one with contrast, flat colors, etc.
As usual, you better experiments with the various settings available at each step.

If I take a relatively regular trace result, I see it has LOT of nodes:

image
image1523Ă—1056 190 KB

It makes difficult to edit the shape to make it more regular.
I don’t know if LB can simplify the shapes. I know Inkscape can do it, sometime with strong alteration of the shape…
For something so simple, I would rather trace the lines by hand, it would be cleaner and easier to edit. For more complex shapes, it can be lot of work. (But I did it for my Christmas presents… Spent lot of time!)

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7

Take a look at the following to see if this helps with your results: :slight_smile:

Optimize Selected Shapes

Attempts to fit the selected shapes to arcs and lines within a specified error tolerance. Useful for reducing the point count in a shape, or recovering arcs from software that exports them as many small line segments. (Alt+Shift+O)

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