png2svgcircles

This Groovy script takes a PNG as input and creates an SVG where solidly filled areas will be filled with randomly sized circles of the same color.

This code started its life as Javascript gist provided by gouldingken.

Requirements for running

The easiest way to run this is to install sdkman and then install compatible Java and Groovy packages.

• java 11.0.2-open
• groovy 3.0.14

Usage (command line options)

Usage: png2svgcircles.groovy 
      [-hV] [-d=<doubleOffset>] -i=<inputPngFile>
      [-m=<maxRadius>] [-n=<numCircles>]
      -o=<outputSvgFile> [-r=<numRetriesPerCircle>]
      [-s=<spacing>] [-t=<tolerance>] [-x=<minRadius>]
      [-c=<omitColors>]...
Draws an SVG using random circles from a simple PNG
  -c, --color-skip=<omitColors>
      Colors (argb values) to be omitted. Can be included
      multiple times to omit multiple colors
  -d, --double-circles-offset=<doubleOffset>
      Double the placed circles with each doubled circle
      having the radius reduced by this much
  -h, --help
      Show this help message and exit.
  -i, --input=<inputPngFile>
      The input PNG file
  -m, --min-radius=<minRadius>
      The minimum circle radius - default is 10
  -n, --num-circles=<numCircles>
      Number of circles to try to place - default is 2000
  -o, --output=<outputSvgFile>
      The output SVG file
  -r, --retries=<numRetriesPerCircle>
      Number of retries for placing each circle - default
      is 1000
  -s, --spacing=<spacing>
      Minimum space between circles - default is 5
  -t, --color-tolerance=<tolerance>
      Color tolerance for color matching, in percentage.
      Range is 0.0 (any color will match) to 1.0 (exact
      color match required). The alpha channel is
      ignored. Default is 1.0
  -V, --version
      Print version information and exit.
  -x, --max-radius=<maxRadius>
      The maximum circle radius - default is 50

Examples

Example 1

Two color PNG with a transparent background at relatively low resolution. It includes circle doubling to provide tolerace for 3d printing designs, etc.

groovy png2svgcircles.groovy -i images/26-and-oval.png -o images/26-and-oval.svg -s 5 -m 10 -x 40 -c -1 -d 1

Sample input file 26-and-oval.png

Example output file 26-and-oval.svg

Example 2

groovy png2svgcircles.groovy -i images/red-star.png -o images/red-star.svg -s 2 -m 5 -x 30 -c 0

Sample input file red-star.png

Example output file red-star.svg

Example 3

And an example for ResinChem Tech where we use the tolerance option, -t, to better handle images that have non-uniform coloring.

groovy png2svgcircles.groovy -i images/Chicken_New01.png -o images/Chicken_New01.svg -s 1 -m 2 -x 20 -t 0.5

Sample input file Chicken_New01.png

Example output file Chicken_New01.svg