Engraving with Dithered Images
When image engraving with a laser diode, our final results may not always be as we would like when using different wood types and other materials with unknown engraving characteristics. One method we sometimes use to prepare images for engraving on new materials uses an editing method called 'Dithering' to process an image before generating a gcode file.
Dithering an image results in an image that is similar to the half-toned images we see printed in books and newspapers. A short PDF describing the dithering process in more detail can be downloaded from our web site here: http://www.picengrave.com/forum/viewforum.php?f=9
The following images were dithered with PicEdit Lite, and then engraved using PicLaser Lite DL version on three different wood types for comparison purposes. All were engraved on my Emblaser using the exact same gcode file with no changes.
The settings I used were: 50ipm/1270mm/m feed rate - 0.0075inches/0.1905 pixel resolution - S0 to S255 laser power. Each took 1hr and 4min to engrave using a horizontal engraving angle. The gcode has 291,636 lines.
The first example is on a wood marked "Craft Wood, made in New Zealand", and it looks like a type of pine. The second is on Poplar, and the third is on Baltic Birch plywood.
The final image is the original dithered image I used to generate the gcode. For comparison purposes, I have re-sized the original to match the scanned examples. The original image I used for the gcode was 540 pixels square, and the engravings were 4.05inches/103mm square.