A golang CLI for extracting a color palette from an image
This program will read an image from disk, and then produce a given number of json-formatted RGBA values to use for something pretty.
To use this tool, install Go, build a binary using go build, and place this somewhere in your PATH.
You can invoke it with the following options:
swatchout -numcolors={integer} {/path/to/image}
For an example, a simple demonstration with Edmund Tarbell's excellent painting from 1907, 'Preparing for the Matinee'.
Using swatchout on this image with numcolors set to 15 produces the following array of RGBA values:
[{"r":89,"g":84,"b":51,"a":1},{"r":177,"g":168,"b":146,"a":1},{"r":166,"g":156,"b":133,"a":1},{"r":207,"g":196,"b":173,"a":1},{"r":235,"g":230,"b":212,"a":1},{"r":110,"g":103,"b":69,"a":1},{"r":140,"g":125,"b":92,"a":1},{"r":156,"g":143,"b":117,"a":1},{"r":28,"g":36,"b":18,"a":1},{"r":56,"g":56,"b":32,"a":1}]
Another example, using Titian's famous painting 'Bacchus and Ariadne'.
Using swatchout on this image with numcolors set to 20 produces the following array of RGBA values:
[{"r":228,"g":221,"b":184,"a":1},{"r":91,"g":66,"b":39,"a":1},{"r":139,"g":160,"b":178,"a":1},{"r":99,"g":110,"b":114,"a":1},{"r":40,"g":51,"b":69,"a":1},{"r":173,"g":143,"b":104,"a":1},{"r":122,"g":140,"b":154,"a":1},{"r":34,"g":31,"b":17,"a":1},{"r":60,"g":80,"b":118,"a":1},{"r":69,"g":68,"b":49,"a":1},{"r":208,"g":173,"b":135,"a":1},{"r":50,"g":42,"b":24,"a":1},{"r":87,"g":86,"b":68,"a":1},{"r":117,"g":101,"b":72,"a":1},{"r":150,"g":112,"b":78,"a":1},{"r":95,"g":121,"b":166,"a":1},{"r":179,"g":188,"b":177,"a":1},{"r":66,"g":52,"b":30,"a":1},{"r":71,"g":96,"b":143,"a":1},{"r":120,"g":81,"b":50,"a":1}]
See this CodePen and this CodePen for a more visual example.