import { S as SsimOptions } from './types-ClU9XBY2.js';

/**
 * MS-SSIM (Multi-Scale Structural Similarity Index)
 *
 * Reference:
 * Z. Wang, E. P. Simoncelli and A. C. Bovik, "Multi-scale structural similarity
 * for image quality assessment," Invited Paper, IEEE Asilomar Conference on
 * Signals, Systems and Computers, Nov. 2003
 *
 * This implementation matches the original MATLAB implementation exactly.
 */

/**
 * MS-SSIM options extending base SSIM options
 */
interface MsssimOptions extends SsimOptions {
    /** Number of scales (default: 5) */
    level?: number;
    /** Weights for each scale (default: [0.0448, 0.2856, 0.3001, 0.2363, 0.1333]) */
    weight?: number[];
    /** Combination method: 'product' or 'wtd_sum' (default: 'product') */
    method?: "product" | "wtd_sum";
}
/**
 * Compute MS-SSIM between two images
 *
 * @param image1 - First image data (RGBA format, 4 bytes per pixel)
 * @param image2 - Second image data (RGBA format, 4 bytes per pixel)
 * @param output - Optional output buffer for SSIM map visualization at finest scale (RGBA format)
 * @param width - Image width in pixels
 * @param height - Image height in pixels
 * @param options - MS-SSIM computation options
 * @returns MS-SSIM score (0-1, where 1 is identical)
 *
 * @example
 * ```typescript
 * // Basic usage
 * const score = mssim(img1, img2, undefined, width, height);
 *
 * // With SSIM map output
 * const output = new Uint8ClampedArray(width * height * 4);
 * const score = mssim(img1, img2, output, width, height);
 * // output now contains grayscale SSIM map at the finest scale
 * ```
 */
declare function msssim(image1: Uint8ClampedArray | Uint8Array | Buffer, image2: Uint8ClampedArray | Uint8Array | Buffer, output: Uint8ClampedArray | Uint8Array | Buffer | undefined, width: number, height: number, options?: MsssimOptions): number;

export { type MsssimOptions, msssim as default, msssim };