import { StorageMethod } from "../types";
export declare class Shutter {
    private videoInput;
    private previewInput;
    private latestCapture;
    /**
     * Shutter is used for taking pictures from the video stream
     * @param {Object} opts
     * @param {HTMLVideoElement} opts.original - The raw, higher resolution video to pull photos from
     * @param {HTMLVideoElement} opts.preview - Another video stream, can be used as a downscaled preview of the original stream
     */
    constructor({ original, preview }: {
        original: HTMLVideoElement;
        preview: HTMLVideoElement;
    });
    /**
     * Helper function for choosing correct video element
     * @param {Object} opts
     * @param {("original" | "preview")} [opts.source=original] - Which stream should be selected
     * @returns {HTMLVideoElement} The video element all changes should be applied to
     */
    private selectVideoInput;
    /**
     * Takes and possibly saves a photo of the specified stream
     * @param {Object} opts
     * @param {StorageMethod} [opts.save] - If the photo should be saved to LocalStorage
     * @param {("original" | "preview")} [opts.source=original] - Which stream the capture should be performed on
     * @returns {string} Photo represented as data URL
     */
    capture({ save, source }?: {
        save?: StorageMethod;
        source?: "original" | "preview";
    }): string;
    /**
     * Captures an image from the video stream and downloads it to the browser
     * @param {Object} opts
     * @param {("original" | "preview")} [opts.source=original] - Which stream the capture should be performed on
     * @param {string} [opts.filename] - Name to use for downloaded image
     * @returns {boolean} If the image was downloaded successfully
     */
    captureAndDownload({ source, filename }: {
        source?: "original" | "preview";
        filename?: string;
    }): boolean;
    /**
     * Downloads the image last captured by the shutter
     * @param {string} [filename] - Name to use for downloaded image
     * @returns {boolean} If the iamge was downloaded successfully
     */
    downloadLatestCapture(filename?: string): boolean;
}