Writing Plugins

There are two types of plugins you can write for Jimp:

1. Image format plugins
2. Image manipulation plugins

You can combine plugins to create a Custom Jimp.

Image format plugins

Image format plugins are responsible for loading and saving images in a specific format.

For example, the bmp package is responsible for loading and saving BMP images.

An image format plugins is composed of two functions: encode and decode.

import { Format } from "@jimp/types";
import WEBP, { WEBPOptions } from "webp-js";

export default function webp() {
  return {
    mime: "image/webp",
    // Encode the bitmap as a WEBP image
    encode: (bitmap, options: WEBPOptions = {}) =>
      WEBP.encode(bitmap, quality).data,
    // Decode a WEBP image into a bitmap
    decode: (data) => WEBP.decode(data),
  } satisfies Format<"image/webp">;
}

Image manipulation plugins

Image manipulation plugins are responsible for manipulating images.

For example, the blur package is responsible for applying a blur effect to an image.

An image manipulation method takes an image as its first argument, does something to it, and returns a new image.

import { JimpClass } from "@jimp/types";
import { BlurOptions } from "blur-ts";

export const methods = {
  /**
   * A blur effect
   *
   * @example
   * ```ts
   * import { Jimp } from "jimp";
   *
   * const image = await Jimp.read("test/image.png");
   *
   * image.blur(5);
   * ```
   */
  blur<I extends JimpClass>(image: I, r: number) {
    // Implementation
  },
};

Generally our method APIs follow the following pattern:

• They can take 1 primitive as an option (other than image)
• Otherwise they take and options object defined and validated by zod.