Glowforge app seems to ignore resolution of PNG graphic

[Jules]

Brevity is the soul of wit.
(And yes, I realize that coming from me, that is incredibly ironic.)

[jamesdhatch]

Now that’s a complete sentence.

I bet Discourse didn’t yell at you

[jamesdhatch]

@Jules

And yes, I realize that coming from me, that is incredibly ironic.

Does that imply you’re generally witless?

[Jules]

Discourse has been yelling at me from day one. (All those tutorials? I can’t do a damned thing without it telling me that it’s similar to something I’ve already posted.)

And yes, it does.

[jamesdhatch]

@Jules

I can’t do a damned thing without it telling me that it’s similar to something I’ve already posted

yeah, that one is a real irritant. And the one where it warns you that you’ve already had several replies in the same thread and maybe you should let other people pipe in…even though there are 150 other replies…

[Jules]

If we continue this conversation, we’ll both see it.

[palmercr]

Yes Discourse doesn’t like conversations!

[evansd2]

This?

https://community.glowforge.com/t/inkscape-cut-outline/18p053

And this:

Using Inkscape Fill for Cutlines

Here is a quick tip for the Inkscape users out there. Say you have a complex object, or group of objects, that you want to create a vector cut path around. A quick way to do that is draw a rectangle around the object and use the fill command (clicking inside the rectangle but not the object)… [s1] [s2] This will create a new object with a hole cut in it. You then can use Path → Break Apart and delete the two leftover rectangles. [s3] Giving you a nice cut outline to your object. [s4] I…

[will_bain]

@evansd2 Thanks for the cutlines info! I will give that a try.

– Will

[icirellik]

Discourse is actually all about conversations it’s one of their main features.

“Conversations, not pages”

All these minor nags are just reminders to keep the conversation on topic and help moderate duplicate posts. If you’ve ever had to moderate a Sharepoint site at a large enterprise you know the pain.

[will_bain]

@evansd2 I appreciate the info, but it appears that method of cutting out around an object only applies to vector objects. I am trying to cut out around an image object (raster). Inkscape appears not to be able to do this. When I use the fill tool, it doesn’t produce a vector boundary; it just fills in the pixels outside the image. Back to the drawing board.

– Will

[Jules]

You can use the Inkscape auto-trace. (Believe it’s called Trace Bitmap, but I’m away from the computer.)

You can also generate a cut line on a raster image using the Glowforge Trace tool, and it’s a good one.

Instructions for using it here:

Glowforge Interface - Using the Trace Tool

The Trace Tool in the Glowforge User Interface can be used to scan printed artwork for engraving, and to create cut lines around the artwork, or inside the artwork, by clicking with the mouse. There are a couple of ways to do things with the Trace Tool. (I’m going to borrow one of Glowforge’s freebies to demonstrate since my drawing skills are non-existent. I printed this airplane out - pretend it’s hand drawn.) Procedure To Scan a Physical Drawing and Add Cut Lines: Black ink d…

[evansd2]

What Jules said.

If your image doesn’t want to trace very well due to specifics like contrast and whatnot, go back to gimp/ps/whatever and process it until it’s ready to be traced (edge detect and whatnot can help here) Import your newly over processed image into the same svg. Snap your good image to your over processed one, trace away.

Delete overprocessed garbage image from the svg, and now you have nice vector paths overlaid exactly on your “good” image, and you’re in business.

[will_bain]

@Jules Yes, the trace tool built into the Glowforge is quite nice, but it doesn’t (yet) include any binary morphology filters, such as dilate (grow), erode (shrink) or skeletonize. I have implemented all these filters before, and they’re all well-documented in the literature, but just not part of Glowforge yet. I will keep trying to find a good workflow, though, and when I do, I will share it with the community. Thanks for your suggestions.

[Jules]

Inkscape then. (Unless you own Illustrator or CorelDraw or Affinity Designer. You can use Offset to morph your outlines once you have them created.)

At least you’ve eliminated a few that won’t work for you.

[dwardio]

You might be amazed/amused at the level of control Discourse allows. Here’s an excerpt of the settings for the (non-GF) site I manage…

[jaz]

Thanks for all the helpful suggestions!

@will_bain, were you able to upload your design at the size you expected?

[will_bain]

@jaz Yes, I finally figured it out. It’s a complicated workflow involving GIMP and Inkscape, because of a bug in Inkscape in which it refuses to read in the image resolution during import, even if you check the box.

In GIMP, I make sure the image has a blank, white background, and save the image at 90 dpi, because that’s all Inkscape can understand.

After importing it into Inkscape, I scale the image using a simple ratio based on the 90 dpi. Next, I use the trace bitmap tool in brightness cutoff mode and a threshold of 0.99, making sure to check the Invert image checkbox.

This results in very few paths, and I can easily delete all but the one or two I want if I make them all colored outlines with no fill and list them in the Objects dialog pane. Then I usually do an outset on the remaining path(s) to give a little extra room around the engraved image. The resulting file contains the bitmap to engrave and the cut path, and Glowforge brings it all in together at the correct size.

– Will Bain

[jaz]

Thanks for your reply – I’m glad it’s working. If you run into anything else, please post a new topic.