/** @format */
/**
 * Class representing WebP filters.
 */
export declare class WebPFilters {
    /**
     * Predicts a line of pixels.
     * @param {InputBuffer<Uint8Array>} src - Source input buffer.
     * @param {InputBuffer<Uint8Array>} pred - Prediction input buffer.
     * @param {InputBuffer<Uint8Array>} dst - Destination input buffer.
     * @param {number} length - Length of the line.
     * @param {boolean} inverse - Whether to apply inverse prediction.
     */
    private static predictLine;
    /**
     * Applies horizontal filter to the image data.
     * @param {Uint8Array} src - Source image data.
     * @param {number} width - Width of the image.
     * @param {number} _height - Height of the image.
     * @param {number} stride - Stride of the image.
     * @param {number} row - Starting row.
     * @param {number} numRows - Number of rows to process.
     * @param {boolean} inverse - Whether to apply inverse filter.
     * @param {Uint8Array} _out - Output image data.
     */
    private static doHorizontalFilter;
    /**
     * Applies vertical filter to the image data.
     * @param {Uint8Array} src - Source image data.
     * @param {number} width - Width of the image.
     * @param {number} _height - Height of the image.
     * @param {number} stride - Stride of the image.
     * @param {number} row - Starting row.
     * @param {number} numRows - Number of rows to process.
     * @param {boolean} inverse - Whether to apply inverse filter.
     * @param {Uint8Array} out - Output image data.
     */
    private static doVerticalFilter;
    /**
     * Predicts a gradient value.
     * @param {number} a - First value.
     * @param {number} b - Second value.
     * @param {number} c - Third value.
     * @returns {number} The predicted gradient value.
     */
    private static gradientPredictor;
    /**
     * Applies gradient filter to the image data.
     * @param {Uint8Array} src - Source image data.
     * @param {number} width - Width of the image.
     * @param {number} _height - Height of the image.
     * @param {number} stride - Stride of the image.
     * @param {number} row - Starting row.
     * @param {number} numRows - Number of rows to process.
     * @param {boolean} inverse - Whether to apply inverse filter.
     * @param {Uint8Array} out - Output image data.
     */
    private static doGradientFilter;
    /**
     * Applies horizontal filter to the image data.
     * @param {Uint8Array} data - Source image data.
     * @param {number} width - Width of the image.
     * @param {number} height - Height of the image.
     * @param {number} stride - Stride of the image.
     * @param {Uint8Array} filteredData - Output filtered image data.
     */
    private static horizontalFilter;
    /**
     * Applies horizontal unfilter to the image data.
     * @param {number} width - Width of the image.
     * @param {number} height - Height of the image.
     * @param {number} stride - Stride of the image.
     * @param {number} row - Starting row.
     * @param {number} numRows - Number of rows to process.
     * @param {Uint8Array} data - Image data to be unfiltered.
     */
    private static horizontalUnfilter;
    /**
     * Applies vertical filter to the image data.
     * @param {Uint8Array} data - Source image data.
     * @param {number} width - Width of the image.
     * @param {number} height - Height of the image.
     * @param {number} stride - Stride of the image.
     * @param {Uint8Array} filteredData - Output filtered image data.
     */
    private static verticalFilter;
    /**
     * Applies vertical unfilter to the image data.
     * @param {number} width - Width of the image.
     * @param {number} height - Height of the image.
     * @param {number} stride - Stride of the image.
     * @param {number} row - Starting row.
     * @param {number} numRows - Number of rows to process.
     * @param {Uint8Array} data - Image data to be unfiltered.
     */
    private static verticalUnfilter;
    /**
     * Applies gradient filter to the image data.
     * @param {Uint8Array} data - Source image data.
     * @param {number} width - Width of the image.
     * @param {number} height - Height of the image.
     * @param {number} stride - Stride of the image.
     * @param {Uint8Array} filteredData - Output filtered image data.
     */
    private static gradientFilter;
    /**
     * Applies gradient unfilter to the image data.
     * @param {number} width - Width of the image.
     * @param {number} height - Height of the image.
     * @param {number} stride - Stride of the image.
     * @param {number} row - Starting row.
     * @param {number} numRows - Number of rows to process.
     * @param {Uint8Array} data - Image data to be unfiltered.
     */
    private static gradientUnfilter;
    /**
     * No filter.
     */
    static readonly filterNone = 0;
    /**
     * Horizontal filter.
     */
    static readonly filterHorizontal = 1;
    /**
     * Vertical filter.
     */
    static readonly filterVertical = 2;
    /**
     * Gradient filter.
     */
    static readonly fitlerGradient = 3;
    /**
     * End marker for filters.
     */
    static readonly fitlerLast: number;
    /**
     * Best filter.
     */
    static readonly fitlerBest = 5;
    /**
     * Fast filter.
     */
    static readonly filterFast = 6;
    /**
     * Array of filter functions.
     */
    static readonly filters: (typeof WebPFilters.horizontalFilter | undefined)[];
    /**
     * Array of unfilter functions.
     */
    static readonly unfilters: (typeof WebPFilters.horizontalUnfilter | undefined)[];
}