/**
 * Options for {@link prepareImage}. All fields are optional; defaults are
 * conservative so calling `prepareImage(file)` is safe.
 */
interface PrepareImageOptions {
    /**
     * Maximum file size in bytes after re-encoding. If the encoded image still
     * exceeds this size, `prepareImage` keeps reducing the JPEG/WebP quality
     * (down to 0.4) before emitting a warning. Default: 2 MiB.
     */
    maxBytes?: number;
    /** Maximum width in CSS pixels after downscale. Default: 2048. */
    maxWidth?: number;
    /** Maximum height in CSS pixels after downscale. Default: 2048. */
    maxHeight?: number;
    /**
     * Output format. `auto` keeps the source format when it is JPEG, PNG or WebP,
     * re-encodes GIF as `image/png` (animation is flattened), and falls back to
     * `image/jpeg` for anything else (e.g. AVIF).
     *
     * The request is not a guarantee: a platform that cannot encode the requested
     * format silently produces another one, and
     * {@link PrepareImageResult.mediaType} then reports what was actually written.
     */
    convertTo?: 'auto' | 'webp' | 'jpeg' | 'png';
    /** Initial JPEG/WebP quality. Default: 0.85. */
    quality?: number;
}
/** Result of preparing an image for EPUB embedding. */
interface PrepareImageResult {
    /** Re-encoded binary payload, ready to drop into an EPUB. */
    data: Uint8Array;
    /**
     * MIME type of the bytes in {@link PrepareImageResult.data}, taken from the
     * encoder's output rather than from the requested format. Browsers that
     * cannot encode the requested format fall back to another one; a warning is
     * added whenever that happens.
     */
    mediaType: string;
    /** Decoded pixel width after any downscale step. */
    width: number;
    /** Decoded pixel height after any downscale step. */
    height: number;
    /** Diagnostic notices (downscaling, quality drops, format fallbacks). */
    warnings: string[];
}
/**
 * Decodes an image, downscales it if it exceeds the given pixel bounds, and
 * re-encodes it to fit within {@link PrepareImageOptions.maxBytes}.
 *
 * Runs only in browsers (uses `createImageBitmap`, `OffscreenCanvas`, and
 * `HTMLCanvasElement`). The library itself does not depend on this module —
 * import it from `@libraz/mejiro/image` only when needed.
 */
declare function prepareImage(file: Blob | File, options?: PrepareImageOptions): Promise<PrepareImageResult>;

export { type PrepareImageOptions, type PrepareImageResult, prepareImage };