Bitmap manipulation to adjust the color in an image.

color

Apply multiple color modification rules

• @param {array} actions list of color modification rules, in following format: { apply: '', params: [ ] }
• @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.color([{ apply: "red", params: [100] }]);
}

main();

Jimp supports advanced colour manipulation using a single method as follows:

image.color([
  { apply: "hue", params: [-90] },
  { apply: "lighten", params: [50] },
  { apply: "xor", params: ["#06D"] },
]);

The method supports the following modifiers:

| Modifier | Description | | ----------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | lighten {amount} | Lighten the color a given amount, from 0 to 100. Providing 100 will always return white (works through TinyColor) | | brighten {amount} | Brighten the color a given amount, from 0 to 100 (works through TinyColor) | | darken {amount} | Darken the color a given amount, from 0 to 100. Providing 100 will always return black (works through TinyColor) | | desaturate {amount} | Desaturate the color a given amount, from 0 to 100. Providing 100 will is the same as calling greyscale (works through TinyColor) | | saturate {amount} | Saturate the color a given amount, from 0 to 100 (works through TinyColor) | | greyscale {amount} | Completely desaturates a color into greyscale (works through TinyColor) | | spin {degree} | Spin the hue a given amount, from -360 to 360. Calling with 0, 360, or -360 will do nothing - since it sets the hue back to what it was before. (works through TinyColor) | | hue {degree} | Alias for spin | | mix {color, amount} | Mixes colors by their RGB component values. Amount is opacity of overlaying color | | tint {amount} | Same as applying mix with white color | | shade {amount} | Same as applying mix with black color | | xor {color} | Treats the two colors as bitfields and applies an XOR operation to the red, green, and blue components | | red {amount} | Modify Red component by a given amount | | green {amount} | Modify Green component by a given amount | | blue {amount} | Modify Blue component by a given amount |

brightness

Adjusts the brightness of the image

• @param {number} val the amount to adjust the brightness, a number between -1 and +1
• @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.brightness(20);
}

main();

contrast

Adjusts the contrast of the image

• @param {number} val the amount to adjust the contrast, a number between -1 and +1
• @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.contrast(70);
}

main();

posterize

Apply a posterize effect

• @param {number} n the amount to adjust the contrast, minimum threshold is two
• @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.posterize(5);
}

main();

opacity

Multiplies the opacity of each pixel by a factor between 0 and 1

• @param {number} f A number, the factor by which to multiply the opacity of each pixel
• @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.opacity(80);
}

main();

sepia

Applies a sepia tone to the image

• @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.sepia();
}

main();

fade

Fades each pixel by a factor between 0 and 1

• @param {number} f A number from 0 to 1. 0 will haven no effect. 1 will turn the image completely transparent.
• @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.fade(0.7);
}

main();

convolution

Sum neighbor pixels weighted by the kernel matrix. You can find a nice explanation with examples at GIMP's Convolution Matrix plugin

• @param {array} kernel a matrix to weight the neighbors sum
• @param {number} edgeHandling (optional) define how to sum pixels from outside the border
• @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.convolution(
    [
      [-1, -1, -1],
      [-1, 8, -1],
      [-1, -1, -1],
    ],
    jimp.EDGE_EXTEND
  );
}

main();

opaque

Set the alpha channel on every pixel to fully opaque

• @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.opaque();
}

main();

pixelate

Pixelates the image or a region

• @param {number} size the size of the pixels
• @param {number} x (optional) the x position of the region to pixelate
• @param {number} y (optional) the y position of the region to pixelate
• @param {number} w (optional) the width of the region to pixelate
• @param {number} h (optional) the height of the region to pixelate
• @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.pixelate(10);
}

main();

convolute

Applies a convolution kernel to the image or a region

• @param {array} kernel the convolution kernel
• @param {number} x (optional) the x position of the region to apply convolution to
• @param {number} y (optional) the y position of the region to apply convolution to
• @param {number} w (optional) the width of the region to apply convolution to
• @param {number} h (optional) the height of the region to apply convolution to
• @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");

  // make me better
  image.pixelate(kernal);
}

main();