/**
 * Where a face sits in the frame, as a fraction of width and height; 0.5, 0.5 is centre.
 * Normalised rather than in pixels because the receiver's tile is a different size.
 */
export type Framing = {
    x: number;
    y: number;
};
export declare const CENTRED: Framing;
/** Below this, the detection is not trusted enough to move anyone's crop. */
export declare const MIN_CONFIDENCE = 0.5;
/**
 * How many samples have to find a face before the crop may move. One detection scraping
 * past MIN_CONFIDENCE is not enough; the cost of being wrong is everybody's view.
 */
export declare const MIN_SAMPLES = 3;
/** One frame's answer: where the largest face was, and how sure the model was. */
export type FramingSample = Framing & {
    score: number;
};
export declare function combineSamples(samples: readonly FramingSample[]): Framing | null;
export declare function detectFraming(stream: MediaStream | null | undefined): Promise<Framing | null>;