I’ve been asked to explain the “Vectors per Pixel:” parameter.
Imagine that you have a picture 30 by 30 pixels that is white with a black dot in the middle. The dot is 2 by 2 pixels. Like this one:
If you were to reproduce this as a lithophane of the same dimensions, i.e. 1 pixel = 1 mm (30mm x 30mm), at 1 Vector per Pixel, a grid of points 30 by 30 would be created in the X and Y planes, each point (called a vector) would be placed in the centre of the pixel and its Z (height) would be set based upon the inverse brightness of the original image.
Each of those points will then be converted into a surface of connected triangles.
Below, you can see the effect of having 1 Vector per Pixel upto 5 Vectors per Pixel
For square areas such as our 2 by 2 pixel black dot, the 1 vector per pixel looks OK, but as you add more complex patterns, this is often too coarse for most images. Although the 5 Vectors per Pixel looks best, this quality is unlikely to be achieved by an FDM printer and the number of triangles is very large causing the STL file and the processing time to increase enormously.
The output quality also depends on the original image and the output size you select, so it’s not possible for me to specify exactly what settings you should use, it all comes down to your preferences, the printer being used, how you are going to print the lithophane and how long you are prepared to wait to process the image into a print.
Hope that clears things up 🙂