/**
 * RGB轉HEX(16進位)色碼
 * ex: rbg(0,0,0) -> #000000
 *
 * @param rgbStr RGB字串
 */
export declare function rgbToHex(rgbStr: string): string | undefined;
/**
 * HEX(16進位)色碼轉轉RGB
 * ex: #000000 -> rgb(0,0,0)

 * @param hexStr HEX字串
 * @param opacity 透明度 (提供透明度參數的話, 會轉回 RGBA)
 */
export declare function hexToRGB(hexStr: string, opacity?: number): string | undefined;
/**
 * 空值轉Null
 * ex: '' -> null
 * ex: 0 -> null
 * ex: undefined -> null
 *
 * @param value
 * @param defaultValue
 */
export declare function emptyToNull<T extends string | number | null>(value?: T): T | null;
/**
 * 轉數字
 * ex: 1234 -> 1234
 *
 * @param value
 * @param defaultValue
 */
export declare function anyToNumber(value: any, defaultValue?: number): number;
/**
 * 轉布林
 * ex: 'true' => true
 *
 * @param value
 * @param isNotBooleanToUndefined
 */
export declare function anyToBoolean(value: any, isNotBooleanToUndefined?: boolean): boolean | undefined;
/**
 * File 轉 Base64Str
 *
 * @param file
 */
export declare function fileToBase64(file: File): Promise<string>;
/**
 * Base64 轉 Blob
 * ex: JVBERi0xLjYNJeL...
 * @param base64Str
 * @param contentType
 */
export declare function base64ToBlob(base64Str: string, contentType: string): Blob;
/**
 * Base64 轉 Blob (包含 contentType)
 * ex: data:application/acrobat;base64, JVBERi0xLjYNJeL...
 *
 * @param base64Str
 */
export declare function base64ToBlobWithContentType(base64Str: string): Blob | null;
/**
 * 將物件資料轉成 FormData
 * ex: {
 *     profile: {name: 'jack'}
 * }
 *
 * @param data
 */
export declare function objToFormData(data: {
    [key: string]: any;
}): FormData;