Function normalize

plugins/plugin-color/src/index.ts:281–315

* Normalizes the image. * @example * ```ts * import { Jimp } from "jimp"; * * const image = await Jimp.read("test/image.png"); * * image.normalize(); * ```

(image: I)

   * ```
   */
  normalize<I extends JimpClass>(image: I) {
    const h = histogram(image);

    // store bounds (minimum and maximum values)
    const bounds = {
      r: getBounds(h.r),
      g: getBounds(h.g),
      b: getBounds(h.b),
    };

    // apply value transformations
    image.scan((_, __, idx) => {
      const r = image.bitmap.data[idx + 0]!;
      const g = image.bitmap.data[idx + 1]!;
      const b = image.bitmap.data[idx + 2]!;

      image.bitmap.data[idx + 0] = normalizeValue(
        r,
        bounds.r[0]!,
        bounds.r[1]!,
      );
      image.bitmap.data[idx + 1] = normalizeValue(
        g,
        bounds.g[0]!,
        bounds.g[1]!,
      );
      image.bitmap.data[idx + 2] = normalizeValue(
        b,
        bounds.b[0]!,
        bounds.b[1]!,
      );
    });

    return image;
  },

  /**
   * Inverts the colors in the image.