imghash/dist/index.mjs

Image perceptual hash calculation for node

import fs from "node:fs";
import { getImageData, imageFromBuffer } from "@canvas/image";
import blockhash from "blockhash-core";
import imageType from "image-type";
import jpeg from "jpeg-js";
//#region \0rolldown/runtime.js
var __commonJSMin = (cb, mod) => () => (mod || cb((mod = { exports: {} }).exports, mod), mod.exports);
//#endregion
//#region src/index.ts
var require_src = /* @__PURE__ */ __commonJSMin(((exports, module) => {
	const JPEG_MAX_MEMORY_USAGE_MB = 1024;
	const HEX_BINARY_LOOKUP = {
		0: "0000",
		1: "0001",
		2: "0010",
		3: "0011",
		4: "0100",
		5: "0101",
		6: "0110",
		7: "0111",
		8: "1000",
		9: "1001",
		a: "1010",
		b: "1011",
		c: "1100",
		d: "1101",
		e: "1110",
		f: "1111",
		A: "1010",
		B: "1011",
		C: "1100",
		D: "1101",
		E: "1110",
		F: "1111"
	};
	const BINARY_TO_HEX_LOOKUP = {
		"0000": "0",
		"0001": "1",
		"0010": "2",
		"0011": "3",
		"0100": "4",
		"0101": "5",
		"0110": "6",
		"0111": "7",
		1e3: "8",
		1001: "9",
		1010: "a",
		1011: "b",
		1100: "c",
		1101: "d",
		1110: "e",
		1111: "f"
	};
	async function hash(filepath, bits, format) {
		format = format || "hex";
		if (format !== "hex" && format !== "binary") throw new Error(`Unsupported format: ${format}`);
		bits = bits || 8;
		if (bits % 4 !== 0) throw new Error(`Invalid bit-length: ${bits}`);
		const fileData = await new Promise((resolve, reject) => {
			if (Buffer.isBuffer(filepath)) return resolve(filepath);
			fs.readFile(filepath, (err, content) => {
				if (err) return reject(err);
				resolve(content);
			});
		});
		let imageData;
		try {
			imageData = getImageData(await imageFromBuffer(fileData));
		} catch (error) {
			if (imageType(fileData)?.mime === "image/jpeg") imageData = jpeg.decode(fileData, { maxMemoryUsageInMB: JPEG_MAX_MEMORY_USAGE_MB });
			else throw error;
		}
		const hexHash = hashRaw(imageData, bits);
		if (format === "binary") return hexToBinary(hexHash);
		return hexHash;
	}
	function hashRaw(data, bits) {
		return blockhash.bmvbhash(data, bits);
	}
	function hexToBinary(s) {
		let ret = "";
		for (let i = 0; i < s.length; i++) if (Object.hasOwn(HEX_BINARY_LOOKUP, s[i])) ret += HEX_BINARY_LOOKUP[s[i]];
		return ret;
	}
	function binaryToHex(s) {
		let ret = "";
		for (let i = 0; i < s.length; i += 4) {
			const chunk = s.slice(i, i + 4);
			if (Object.hasOwn(BINARY_TO_HEX_LOOKUP, chunk)) ret += BINARY_TO_HEX_LOOKUP[chunk];
		}
		return ret;
	}
	module.exports = {
		hash,
		hashRaw,
		hexToBinary,
		binaryToHex
	};
}));
//#endregion
export default require_src();
export {};