/**
 * Image security utilities and Sharp configuration
 * Prevents pixel bomb attacks and validates image dimensions
 */
import sharp from 'sharp';
/**
 * Initialize Sharp with security settings
 * Should be called once at application startup
 */
export declare function initializeSharpSecurity(): void;
/**
 * Validate image buffer before processing
 */
export declare function validateImageBuffer(imageBuffer: Buffer, allowSvg?: boolean): Promise<void>;
/**
 * Validate SVG content for security risks using DOMPurify
 */
export declare function validateSvgContent(svgBuffer: Buffer): Promise<void>;
/**
 * Sanitize SVG content and return cleaned result for testing
 */
export declare function sanitizeSvgContent(svgContent: string): string;
/**
 * Create a secure Sharp instance with safety checks
 */
export declare function createSecureSharpInstance(imageBuffer: Buffer): sharp.Sharp;
/**
 * Execute a Sharp operation with direct instance creation
 * Use this for one-shot operations
 */
export declare function withSecureSharp<T>(imageBuffer: Buffer, operation: (sharp: sharp.Sharp) => Promise<T>): Promise<T>;
/**
 * Process image with timeout protection to prevent DoS attacks
 */
export declare function processImageWithTimeout<T>(operation: () => Promise<T>, timeoutMs?: number): Promise<T>;
/**
 * Safely resize image with dimension validation
 */
export declare function secureResize(sharpInstance: sharp.Sharp, width: number, height: number, options?: sharp.ResizeOptions): sharp.Sharp;
/**
 * Create a Sharp instance with metadata removal for privacy and security
 */
export declare function createSecureSharpWithCleanMetadata(imageBuffer: Buffer): sharp.Sharp;
/**
 * Execute a Sharp operation with direct instance creation and clean metadata
 * Use this for one-shot operations that need automatic cleanup
 */
export declare function withSecureSharpCleanMetadata<T>(imageBuffer: Buffer, operation: (sharp: sharp.Sharp) => Promise<T>): Promise<T>;
/**
 * Validate Sharp processing limits before operations
 */
export declare function validateSharpLimits(width: number, height: number): void;
/**
 * Export security constants for use in other modules
 */
export declare const IMAGE_SECURITY_LIMITS: {
    readonly MAX_INPUT_PIXELS: number;
    readonly MAX_IMAGE_WIDTH: 8192;
    readonly MAX_IMAGE_HEIGHT: 8192;
    readonly MAX_FILE_SIZE: number;
    readonly MAX_SVG_SIZE: number;
    readonly MAX_DPI: 600;
    readonly PROCESSING_TIMEOUT: 30000;
    readonly ALLOWED_IMAGE_FORMATS: ("png" | "jpeg" | "webp" | "jpg" | "gif" | "bmp" | "tiff")[];
};