@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);
  });

Other packages similar to @jimp/plugin-threshold

sharp

Sharp is a high-performance image processing library that supports a wide range of image transformations, including thresholding. It is known for its speed and efficiency, especially with large images.

gm

GraphicsMagick (gm) is a powerful image processing library that provides a wide range of image manipulation features, including thresholding. It is a wrapper around the GraphicsMagick command-line tool and is known for its robustness and versatility.

opencv4nodejs

opencv4nodejs is a Node.js binding for OpenCV, a popular computer vision library. It provides extensive image processing capabilities, including thresholding, and is suitable for more advanced image analysis tasks.

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();

Changelog

v0.22.8 (Thu May 11 2023)

:tada: This release contains work from new contributors! :tada:

Thanks for all your work!

:heart: Sjoerd (@sjoerd108)

:heart: null@php4fan

:heart: null@JunkMeal

🚀 Enhancement

• @jimp/core, jimp
  • Composite: don't write to null pixels #1226 (@sjoerd108)
• @jimp/plugin-color
  • Fix: convolute not defaulting to 0, 0 as starting point #1228 (@sjoerd108)
• @jimp/plugin-rotate
  • Fix: rotate resize param on multiples of 90 #1229 (@sjoerd108)

🐛 Bug Fix

• @jimp/plugin-crop, @jimp/test-utils
  • Fix autocrop mixing up east and west #1227 (@sjoerd108)

📝 Documentation

• Fixed typo in README #1215 (@php4fan)
• jimp
  • Changing the Hiero url #1213 (@JunkMeal)

Authors: 3

• @JunkMeal
• @php4fan
• Sjoerd (@sjoerd108)

---