/** @format */
import { Color } from '../color/color.js';
import { MemoryImage } from './image.js';
import { PaletteUint8 } from './palette-uint8.js';
import { Quantizer } from './quantizer.js';
/**
 * Color quantization using octree,
 * from https://rosettacode.org/wiki/Color_quantization/C
 */
export declare class OctreeQuantizer implements Quantizer {
    /**
     * A constant representing the node is in the heap.
     */
    private static readonly _inHeap;
    /**
     * The root node of the octree.
     */
    private readonly _root;
    /**
     * The palette generated by the quantizer.
     */
    private _palette;
    /**
     * Gets the palette generated by the quantizer.
     */
    get palette(): PaletteUint8;
    /**
     * Constructs an OctreeQuantizer.
     * @param {MemoryImage} image - The image to be quantized.
     * @param {number} [numberOfColors=256] - The number of colors to reduce the image to.
     */
    constructor(image: MemoryImage, numberOfColors?: number);
    /**
     * Inserts a color into the octree.
     * @param {OctreeNode} root - The root node of the octree.
     * @param {number} r - The red component of the color.
     * @param {number} g - The green component of the color.
     * @param {number} b - The blue component of the color.
     * @returns {OctreeNode} The inserted node.
     */
    private nodeInsert;
    /**
     * Pops the top node from the heap.
     * @param {HeapNode} h - The heap.
     * @returns {OctreeNode | undefined} The popped node or undefined if the heap is empty.
     */
    private popHeap;
    /**
     * Adds a node to the heap.
     * @param {HeapNode} h - The heap.
     * @param {OctreeNode} p - The node to add.
     */
    private heapAdd;
    /**
     * Moves a node down the heap to maintain heap property.
     * @param {HeapNode} h - The heap.
     * @param {OctreeNode} p - The node to move.
     */
    private downHeap;
    /**
     * Moves a node up the heap to maintain heap property.
     * @param {HeapNode} h - The heap.
     * @param {OctreeNode} p - The node to move.
     */
    private upHeap;
    /**
     * Folds a node into its parent.
     * @param {OctreeNode} p - The node to fold.
     * @returns {OctreeNode | undefined} The parent node or undefined if the node has children.
     */
    private nodeFold;
    /**
     * Compares two nodes.
     * @param {OctreeNode} a - The first node.
     * @param {OctreeNode} b - The second node.
     * @returns {number} A negative number if a < b, a positive number if a > b, or 0 if they are equal.
     */
    private compareNode;
    /**
     * Gets all leaf nodes of the octree.
     * @param {OctreeNode[]} nodes - The array to store the nodes.
     * @param {OctreeNode} node - The current node.
     */
    private getNodes;
    /**
     * Gets the index of the color in the palette.
     * @param {Color} c - The color.
     * @returns {number} The index of the color in the palette.
     */
    getColorIndex(c: Color): number;
    /**
     * Gets the index of the color in the palette using RGB values.
     * @param {number} r - The red component of the color.
     * @param {number} g - The green component of the color.
     * @param {number} b - The blue component of the color.
     * @returns {number} The index of the color in the palette.
     */
    getColorIndexRgb(r: number, g: number, b: number): number;
    /**
     * Find the index of the closest color to **c** in the **palette**.
     * @param {Color} c - The color to find the closest match for.
     * @returns {Color} The closest color in the palette.
     */
    getQuantizedColor(c: Color): Color;
    /**
     * Convert the **image** to a palette image.
     * @param {MemoryImage} image - The image to convert.
     * @returns {MemoryImage} The palette image.
     */
    getIndexImage(image: MemoryImage): MemoryImage;
}