Laser Engraving Image Preparation
We feel that the most important thing in a Laser Engraving
software package is image preparation. It is not an easy task to convert
an image to a series of black and white pixels. The sketch software uses a proprietary
method for creating a effect that shows edges but still retains dark areas. The
Floyd-Steinberg Dithering is a industry standard for dithering while the Colby method was developed
to enhance the contrast of laser engraved images. We do not need to argue which
is the best approach we make it easy for you to try all three.
Many times enhancing the contrast of the image will help the conversion algorithms. Laser Photo Wizard let you fine tune contrast effects.
Press here to try the free demo: FREE DEMO
This method simpley converts color image to black and white
Sketch will attempt to look at edges and create a solid
sketch of the image. This is very helpful because it is not only artistic, but lower
cost lasers that do not control their power and position as well still can do a
nice rendering on most materials.
Floyd-Steinberg is a dithering algorithm. Dithering is converting
a grayscale image to black and white no gray, such that the density of black dots
in the new image approximates the average grey level in the original.
If you look at a close up of this method you can see how smooth the output is. The
problem is that fine details are lost.
The Colby dithering algorithm was developed for this product
by the author, Ken Colby. Like Floyd-Steinberg it tries to make the density of black
dots in the new image approximate the average grey level in the original. Unlike
Floyd-Steinberg it considers the original image and tries to arrange the dots so
that they tend to appear near the darker areas. This creates a image with higher
contrast but it is less smooth then the Floyd-Steinberg. It should always be used
if you are outputting landscapes or products but with people it is personal choice.
The Colby dithering algorithm works well for details but it does not give smooth results like Floyd-Steinberg. Colby Dot Migration starts with Floyd-Steinberg Dithering but then it uses a proprietary algorithm to move the dots to increase local contrast. It can be very effective but it can also create artifacts so a slider is provided in the advanced settings section to let you select how much of the effect your want.
This method, that works well with wood, increases the contrast
of the engraved image by dithering and also considering the edges of the photo.
3D Gray takes a PNG file with a transparent background and
creates a 3D like engraving. How it works is anyplace that is transparent is changed
to black, the highest engraving value. Any place that is not transparent is dithered
using the selected dithering algorithm. You can select the gray level for the dithered
image. Selecting a low number will make it look like the image is a raised cutout.
Selecting a high number will make it look like an engraved image. Selecting a min
range number like 100 will give a 3D like appearance to the output. To do 3D Gray,
Check the 3D Gray Box an select a dithering method.
Click here to for a step by step guide to 3D Gray.