/**
 * PNG downscaling with Node built-ins only (node:zlib), for device screenshots.
 *
 * Why this exists: `screencap` returns the panel's native resolution (a Pixel 6 is
 * 1080×2340), and vision APIs downscale anything whose long side exceeds ~1568px
 * BEFORE the model sees it. The model then answers with coordinates in the image it
 * saw — a frame nobody on our side knows — so taps land wherever the silent resize
 * put them. Scaling on our side keeps the coordinate space known: the driver records
 * the factor and maps the model's points back to device pixels.
 *
 * Scope is deliberately narrow: 8-bit RGB/RGBA, non-interlaced — what `screencap -p`
 * emits. Anything else (or a parse failure) falls back to the original bytes with
 * scale 1, which is exactly the old behavior.
 */
export interface ScaledPng {
    png: Buffer;
    /** Device pixels per image pixel (≥ 1). Multiply image coordinates by this. */
    toSource: number;
    width: number;
    height: number;
}
/** Downscale so the long side is ≤ maxLongSide; pass small images through untouched. */
export declare function scalePngToLongSide(png: Buffer, maxLongSide: number): ScaledPng;