export declare const salt: string;
/**
 * 将CanvasRenderingContext2D转换为ArrayBuffer
 * @param ctx - CanvasRenderingContext2D
 * @returns {ArrayBuffer} 转换后的ArrayBuffer
 */
export declare function ctx2ab(ctx: CanvasRenderingContext2D): ImageDataArray;
/**
 * 将ArrayBuffer转换为字符串
 * @param buf - ArrayBuffer
 * @returns {string} 转换后的字符串
 */
export declare function ab2str(buf: ArrayBuffer): string;
/**
 * 将字符串转换为ArrayBuffer
 * @param str - 需要转换的字符串
 * @returns {ArrayBuffer} 转换后的ArrayBuffer
 */
export declare function str2ab(str: string): ArrayBuffer;
/**
 * 将ArrayBuffer转换为Base64编码的字符串
 * @param buffer - ArrayBuffer
 * @returns {string} 转换后的Base64编码字符串
 */
export declare function arrayBufferToBase64(buffer: ArrayBuffer): string;
/**
 * 将Base64编码的字符串转换为Uint8Array
 * @param base64String - Base64编码的字符串
 * @returns {Uint8Array} 转换后的Uint8Array
 */
export declare function base64ToUint8Array(base64String: string): ArrayBuffer;
/**
 * 从已经编码了信息的ArrayBuffer提取ImageData
 * @param {Array} buffer ArrayBuffer
 * @param {number} dx 数据偏移x
 * @param {number} dy 数据偏移y
 * @param {number} dw 数据块宽度
 * @param {number} dh 数据块高度
 * @param {number} iw 图像宽度
 * @param {number} ih 图像高度
 * @returns {Object} ImageData包含像素值的数组对象
 */
export declare function abToImageData(buffer: ArrayBuffer, dx: number | undefined, dy: number | undefined, dw: number, dh: number, iw: number, ih: number): ImageData;
/**
 * 从Uint8ClampedArray中提取数据
 * @param { Uint8ClampedArray } buffer 图像数据
 * @returns { String } 解析以后的字符串数据
 */
export declare function extractData(buffer: Uint8ClampedArray | Uint8Array): string;
/**
 * 字符串编码成图片，自动分层
 * @param {string} str 需要编码到图片中的字符串
 */
export declare function splitLayers(str: string): ArrayBuffer[];
type ResultData = {
    success: boolean;
    msg: string;
    msgType: number;
    data: string;
    fileSize?: number;
};
/**
 * 解析APNG
 * @param {ArrayBuffer} buffer read as buffer
 */
/**
 * 解析APNG
 * @param {ArrayBuffer} buffer read as buffer
 */
export declare function decodeApng(buffer: ArrayBuffer): Promise<ResultData>;
type ImageBuffer = ArrayBufferLike | ArrayBuffer;
/**
 * 从图片到buffer
 * @param {*} source dom selector/image url/arraybuffer /base64 iamge
 * @returns {ArrayBuffer} image buffer
 */
export declare function generateCoverBuffer(source: string | ArrayBuffer): Promise<ImageBuffer>;
/**
 * 图像转字符串
 * @param {*} source 源，image src 或者 arrayBuffer
 * @returns {Promise}
 */
export declare function img2str2(source: string | ArrayBuffer, signal?: AbortSignal): Promise<ResultData>;
export {};
/**
 * 字符串转换为base64图片
 * @param {string} str 需要转换的字符串
 * @param {string | ArrayBuffer} cover 选择器/arraybuffer/图片地址
 * @returns {Promise}
 */