/**
 * Composites neutral grey (128,128,128) over each ignoredRegion (fractional
 * 0-1 coordinates) so masked content — timestamps, live counters, ads —
 * contributes nothing to any downstream pixel comparison. Shared by every
 * comparison path (whole-image hash, per-cell grid hash, AI vision) so a
 * region masked once is actually ignored everywhere, not just in the
 * cheapest check.
 */
export declare function applyMask(imagePath: string, ignoredRegions: Array<{
    x: number;
    y: number;
    width: number;
    height: number;
}>): Promise<Buffer>;
/**
 * Generates a pixelmatch diff image highlighting changed pixels in red.
 * Applies the same ignoredRegions mask as screenshotDiffPercent so masked
 * zones don't show as "changed" in the visual output.
 * Returns a PNG Buffer suitable for upload to S3.
 */
export declare function generatePixelmatchDiff(pathA: string, pathB: string, ignoredRegions?: Array<{
    x: number;
    y: number;
    width: number;
    height: number;
}>): Promise<Buffer>;
export declare function screenshotDiffPercent(pathA: string, pathB: string, ignoredRegions?: Array<{
    x: number;
    y: number;
    width: number;
    height: number;
}>): Promise<{
    pHashDistance: number;
    changeLevel: 'IDENTICAL' | 'MINOR' | 'MODERATE' | 'SIGNIFICANT';
}>;
/**
 * Grid-based layout analysis: divides screenshots into a 3×3 grid and computes
 * pHash per cell. Returns which regions changed and where, for the VisualDiff.changes field.
 * Uses sharp's `extract` to crop each cell before hashing.
 */
export declare function gridLayoutDiff(pathA: string, pathB: string, ignoredRegions?: Array<{
    x: number;
    y: number;
    width: number;
    height: number;
}>): Promise<Array<{
    location: string;
    severity: string;
    description: string;
}>>;