import { Image } from '../core/Image';
import { Keypoint } from '../core/Keypoint';
export interface IScoreMinMaxResult {
    ismax: boolean;
    score?: number;
    x?: number;
    y?: number;
    deltax?: number;
    deltay?: number;
    scale?: number;
}
export declare class BRISKLayer {
    protected _below: BRISKLayer;
    protected _above: BRISKLayer;
    private debug;
    private basicSize;
    private layer;
    private _scale;
    private offset;
    private fast;
    private fast58;
    private _T;
    private mode;
    private scores;
    private scores58;
    constructor(mode: number, scale: number, below: BRISKLayer, index: number);
    T: number;
    readonly scale: number;
    above: BRISKLayer;
    below: BRISKLayer;
    setImage(image: Image): void;
    isMax2D(i: number): boolean;
    getScoreMaxAbove(x_layer: number, y_layer: number, threshold: number): IScoreMinMaxResult;
    getScoreMaxBelow(x_layer: number, y_layer: number, threshold: number): IScoreMinMaxResult;
    refine1D(s_05: number, s0: number, s05: number): {
        max: number;
        scale: number;
    };
    refine1D_1(s_05: number, s0: number, s05: number): {
        max: number;
        scale: number;
    };
    refine1D_2(s_05: number, s0: number, s05: number): {
        max: number;
        scale: number;
    };
    refine3D(x: number, y: number): IScoreMinMaxResult;
    getFeatures(): Keypoint[];
    /**
     * Returns interpolated agast scores based on a 2x2 window.
     */
    getAgastScoref(xf: number, yf: number, threshold_in: number, scale_in?: number): number;
    /**
     * Apply gaussian smoothing using a 3x3 kernel.
     */
    private smoothed(x, y);
    /**
     * Returns the AGAST score given (x, y) coordinates.
     */
    private getAgastScore(x, y, threshold_in);
    private getAgastScore_5_8(x, y, threshold);
}