import type { ReversePixelMapper } from "./ReversePixelMapper";
/**
 * Partial derivatives of reverse mapping function.
 */
export type PartialDerivatives = [number, number, number, number];
/**
 * ReversePixelMapper with support of Elliptical Weighted Average color resapmling.
 */
export interface EwaReversePixelMapper extends ReversePixelMapper {
    /**
     * Flags that pixel mapper has constant partial derivatives, so there is
     * no need to recalculate EWA ellipse for each point.
     */
    readonly isConstantPartialDerivatives: boolean;
    /**
     * Returns mapper partial derivatives for given point.
     *
     * @param x
     * @param y
     */
    getPartialDerivatives(x: number, y: number): PartialDerivatives;
}
/**
 * Checks if passed object implements EwaReversePixelMapper interface.
 *
 * @param obj
 */
export declare function isEwaReversePixelMapper(obj: unknown): obj is EwaReversePixelMapper;