/**
 * @file
 *
 * Lazily loads `sharp`, the OPTIONAL peer dependency the image helpers need, and
 * describes the slice of its surface they use.
 *
 * The load is deferred because a static import would drag `sharp`'s
 * platform-specific native binaries into every consumer of this package's index,
 * when only screenshot post-processing needs them. The type is structural for
 * the same reason: this module type-checks without `sharp`'s own types being
 * resolvable.
 */
/**
 * A layer passed to `sharp`'s `composite`.
 */
export interface SharpCompositeLayer {
    readonly input: Buffer;
    readonly left: number;
    readonly top: number;
}
/**
 * The `sharp` entry point the image helpers use.
 */
export type SharpFactory = (input: Uint8Array) => SharpInstance;
/**
 * One `sharp` pipeline.
 */
export interface SharpInstance {
    blur: (this: void, sigma: number) => SharpInstance;
    composite: (this: void, layers: SharpCompositeLayer[]) => SharpInstance;
    metadata: (this: void) => Promise<SharpMetadata>;
    png: (this: void) => SharpInstance;
    resize: (this: void, width: number, height: number, options?: SharpResizeOptions) => SharpInstance;
    toBuffer: (this: void) => Promise<Buffer>;
    trim: (this: void, options: SharpTrimOptions) => SharpInstance;
}
/**
 * The subset of `sharp`'s metadata the image helpers read.
 */
export interface SharpMetadata {
    readonly height?: number | undefined;
    readonly width?: number | undefined;
}
/**
 * The subset of `sharp`'s resize options the image helpers set.
 */
export interface SharpResizeOptions {
    readonly fit: 'cover' | 'fill';
}
/**
 * The subset of `sharp`'s trim options the image helpers set.
 */
export interface SharpTrimOptions {
    /**
     * How far a pixel may differ from the trimmed-away color before it counts as
     * content.
     */
    readonly threshold: number;
}
/**
 * Loads `sharp` on demand.
 *
 * @param caller - Name of the calling helper, so the error says which one needs it.
 * @returns A {@link Promise} that resolves to the `sharp` factory.
 * @throws Error naming the missing optional peer dependency.
 */
export declare function importSharp(caller: string): Promise<SharpFactory>;