/** A decoded JPEG: 8-bit interleaved samples, one or three components. */
export interface DecodedJpeg {
    readonly width: number;
    readonly height: number;
    /** 1 = grayscale, 3 = RGB (already converted from YCbCr where it applies). */
    readonly components: 1 | 3;
    /** `width * height * components` bytes, row-major. */
    readonly samples: Uint8Array;
}
/**
 * Decode a baseline JPEG to interleaved 8-bit samples.
 *
 * @param bytes The JPEG stream, starting at its SOI marker.
 * @returns The decoded image, or `undefined` when the stream is not a baseline
 *          JPEG this decoder handles (progressive, arithmetic, 12-bit, CMYK) or
 *          is malformed — the caller then carries the original bytes through.
 */
export declare function decodeJpeg(bytes: Uint8Array): DecodedJpeg | undefined;