import React from "react";
export interface SrcProps {
    src: string;
    width?: number;
    height?: number;
}
export interface PlaceholderProps {
    height: number;
    width: number;
}
export declare type Props = SrcProps | PlaceholderProps;
/**
 * A responsive image (or placeholder).
 *
 * Renders a single `<img />` tag with responsive styles applied. When `src` is
 * not provided, a placeholder image of the correct size is rendered.
 */
export declare class ResponsiveImage extends React.Component<Props> {
    render(): JSX.Element;
}