import { ImageDataLike, WasmSource } from "./common.js";
export interface QuantizeOptions {
    /**
     * Range: [1, 10], bigger is faster and generate images of lower quality,
     * but may be useful for real-time generation of images.
     *
     * @default 4
     */
    speed?: number;
    /**
     * Range [0, 100], roughly like JPEG. the max 100 means best effort
     * If less than 100, the library will try to use fewer colors.
     *
     * Images with fewer colors are not always smaller, due to increased dithering it causes.
     *
     * @default 75
     */
    quality?: number;
    /**
     * Limit the number of colors in palette, range: [2, 256].
     *
     * @default 256
     */
    colors?: number;
    /**
     * Range [0, 1] float, set to 1 to get nice smooth image.
     *
     * @default 1
     */
    dithering?: number;
}
export interface Options extends QuantizeOptions {
    /**
     * Range [0, 6], bigger means smallest file and slower compression.
     *
     * @default 3
     */
    level?: number;
    /**
     * Is the image made to support progressive loading?
     * Enabling this feature will increase the size of the results.
     *
     * @default false
     */
    interlace?: boolean;
    /**
     * Lossy compress the image to PNG for significant file size reduction.
     * Implements the same functionality as [pngquant](https://pngquant.org)
     *
     * if set to false, properties from `QuantizeOptions` are ignored.
     *
     * @default true
     */
    quantize?: boolean;
    /** @internal */
    bit_depth?: number;
}
export declare const defaultOptions: Required<Options>;
export declare const bitDepth: number[];
export declare const mimeType = "image/png";
export declare const extension = "png";
export declare const loadEncoder: (module_or_path?: WasmSource) => Promise<any>;
export declare const loadDecoder: (module_or_path?: WasmSource) => Promise<any>;
/**
 * Reduces the colors used in the image at a slight loss, using a combination
 * of vector quantization algorithms.
 *
 * Can be used before other compression algorithm to boost compression ratio.
 */
export declare function reduceColors(image: ImageDataLike, options?: QuantizeOptions): Uint8Array;
export declare function encode(image: ImageDataLike, options?: Options): Uint8Array;
export declare function decode(input: Uint8Array): ImageDataLike;