What does Vectors per Pixel mean?


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:

VPerBasePixelIf 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 🙂

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7 thoughts on “What does Vectors per Pixel mean?”

  1. Hello Rocks,
    Your program seems funny and very useful for me, but I have more question: I would like to generate flat and thick outline for my 3D print machine, how to do it? Please give me some suggestion. Sorry for my poor english, as it is not my mother language.

    henry zhang

    1. Hi Henry,

      I’m afraid I don’t understand what you need, are you talking about an outline around the print or a thick border or base for the print. Try changing the “Base/Stand depth” or the “Border” and click on the image to see the effect, hope that helps

      我怕我不明白你需要什么,你说的是周围的打印大纲或厚的边框或基地打印。尝试改变“底座/支架深度”或“边框” ,然后点击图片查看效果,希望帮助


  2. Dear Mark,

    Glad to hear your comment. What I mean is if I use diameter 1mm (therefore the layer height is 0.8mm) to print the stl model (generated form a simple jpg format photo), it looks bad. But maybe it is better that i can set the thickness of photo outline (i.e. a lady face) to suit for my 1mm printer. Is it possible?

    Thanks a lot.


    1. Hi Henry,

      Try printing the lithophane standing on its edge, try these parameters:
      Output Dimension – 100
      Thickness – 7
      Border Thickness – 2
      Thinnest layer – 1
      Vectors per pixel – 5
      Base/Stand depth – 10

      print in natural PLA or ABS

      Good luck 🙂


  3. I want to make a cylindrical lamp shade with 4 or 5 different photos.
    I know i can do the segments but i would like the OD to be 1 piece.
    I resize all my photos to 75 X 75 so they are the same size.
    I will be printing in ABS. which works better white or Natural filament? I have a family member that is getting married next year and I want to make the litho lampshades for the table center pieces.

    1. Hi Dale,

      If you put all your pictures into one image side by side and save that, you can then use the cylinder shape and have them placed all the way around.
      If you tell me the height and diameter of the cylinder that you’d like to produce, I can tell you the correct size for your images and the best parameters to use.
      Both the white and the natural work well, the natural is usually cheaper too.

      Hope that helps?


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