engraving a photo with a laser cutter

Starting with:

First up, this requires some awareness of the difference between raster and vector images

Raster files are composed of pixels., eg. a normal photograph. In this case the format was JPG. Vector files use mathematical equations to make geometric chapes, lines, and curves with fixed points on a grid to produce an image. A common vector format is SVG.

Raster images are challenging and require more preparation before engraving or etching them with a laser cutter. You need to start with a photo with lots of contrast, eg. with a pure white background and pale clothes to contrast darkish hair (or trim the photo as I did).

One technique is error diffusion raster (Stucki, Jarvis, FloydSteinberg). The darker the grayscale value, the denser the points are set. The point size remains unchanged.

I'm a GIMP user (open source), not a Photoshop user. For my needs I found a couple of good tutorials online:

GIMP tutorial

• Scale image to 300 px/inch
• Convert to black and white
• Histogram adjusted for good range of dark and light areas
• Adjust colour levels histogram towards the centre
• Adjust colour curves to boost the contrast
• Apply sharpening

After the GIMP tutorial I then applied this YouTube Lightburn tutorial:

• import and select the image
• tools > adjust image Alt + I
• Best image mode > Jarvis or Stucki
• DPI – approx 300
• To sharpen:
• Enhance radius: 25
• Enhance amount: 100
• Lighten the face and remove background dots:
• Brightness: 7

Note that the Preview normally looks poor and can be safely ignored! But you can get the time estimate through Preview.

After treatment with the two tutorials:

Laser cut version onto MDF (Medium Density Fibreboard). The contrast is OK but could be improved around the eyes and mouth: