@jimp/plugin-threshold

What is @jimp/plugin-threshold?

@jimp/plugin-threshold is a plugin for the Jimp image processing library that allows you to apply threshold effects to images. This effect converts an image to black and white based on a threshold value, which can be useful for various image processing tasks such as edge detection, binarization, and more.

What are @jimp/plugin-threshold's main functionalities?

Apply Threshold Effect

This feature allows you to apply a threshold effect to an image. The `max` parameter specifies the threshold value. Pixels with a value above this threshold will be set to white, and those below will be set to black.

const Jimp = require('jimp');

Jimp.read('path/to/image.jpg')
  .then(image => {
    image.threshold({ max: 128 })
         .write('path/to/output.jpg');
  })
  .catch(err => {
    console.error(err);
  });

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README

@jimp/plugin-threshold

Lightens an image.

This is useful as a simplified method for processing scanned drawings, signatures, etc

Usage

• @param {number} options object
  • max: A number auto limited between 0 - 255
  • replace: (optional) A number auto limited between 0 - 255 (default 255)
  • autoGreyscale: (optional) A boolean whether to apply greyscale beforehand (default true)
• @param {function(Error, Jimp)} cb (optional) a callback for when complete

import jimp from 'jimp';

async function main() {
  const image = await jimp.read('test/image.png');

  image.threshold({ max: 150 });
  // or
  image.threshold({ max: 200, replace: 200, autoGreyscale: false });
}

main();