Method split

packages/transformers/src/utils/image.js:700–718

* Split this image into individual bands. This method returns an array of individual image bands from an image. * For example, splitting an "RGB" image creates three new images each containing a copy of one of the original bands (red, green, blue). * * Inspired by PIL's `Image.split()

()

     * @returns {RawImage[]} An array containing bands.
     */
    split() {
        const { data, width, height, channels } = this;

        /** @type {typeof Uint8Array | typeof Uint8ClampedArray} */
        const data_type = /** @type {any} */ (data.constructor);
        const per_channel_length = data.length / channels;

        // Pre-allocate buffers for each channel
        const split_data = Array.from({ length: channels }, () => new data_type(per_channel_length));

        // Write pixel data
        for (let i = 0; i < per_channel_length; ++i) {
            const data_offset = channels * i;
            for (let j = 0; j < channels; ++j) {
                split_data[j][i] = data[data_offset + j];
            }
        }
        return split_data.map((data) => new RawImage(data, width, height, 1));
    }

    /**
     * Helper method to update the image data.