export type ImageFormat = "png" | "jpeg" | "gif" | "webp";
export interface ImageDimensions {
    width: number;
    height: number;
}
export interface SharpResizeResult {
    buffer: Buffer;
    mediaType: ImageFormat;
    width: number;
    height: number;
    
    changed: boolean;
}
export interface ResizeOptions {
    maxWidth: number;
    maxHeight: number;
    maxBytes: number;
}
export declare function imageMediaType(format: ImageFormat): string;
export declare function formatBytes(bytes: number): string;

export declare function detectImageFormatFromBuffer(buffer: Buffer): ImageFormat | null;

export declare function readImageDimensions(buffer: Buffer): ImageDimensions | null;
interface SharpLike {
    metadata(): Promise<{
        width?: number;
        height?: number;
        format?: string;
    }>;
    resize(width: number, height: number, options?: {
        fit?: string;
        withoutEnlargement?: boolean;
    }): SharpLike;
    jpeg(options?: {
        quality?: number;
    }): SharpLike;
    png(options?: {
        compressionLevel?: number;
        palette?: boolean;
        quality?: number;
    }): SharpLike;
    webp(options?: {
        quality?: number;
        lossless?: boolean;
    }): SharpLike;
    toBuffer(): Promise<Buffer>;
}
export type SharpFactory = (input: Buffer) => SharpLike;

export declare function resetSharpCacheForTest(): void;

export declare function setSharpFactoryForTest(factory: SharpFactory | null): void;

export declare function tryResizeWithSharp(input: Buffer, format: ImageFormat, options: ResizeOptions): Promise<SharpResizeResult | null>;

export type CompressLevel = "lossy" | "normal" | "clear";
export interface CompressImageOptions {
    
    normalMaxBytes: number;
    
    clearMaxBytes: number;
}
export interface CompressImageResult {
    buffer: Buffer;
    mediaType: ImageFormat;
    width: number;
    height: number;
    
    compressed: boolean;
    
    level: CompressLevel | null;
    originalSize: number;
    compressedSize: number;
    
    savedPercent: number;
}

export declare function tryCompressImageWithSharp(input: Buffer, format: ImageFormat, options: CompressImageOptions): Promise<CompressImageResult | null>;
export {};