diff --git a/.imgbotconfig b/.imgbotconfig
new file mode 100644
index 0000000000000000000000000000000000000000..6a1dfe1ed34601bbbd1b9e2e1935ced5991565ff
--- /dev/null
+++ b/.imgbotconfig
@@ -0,0 +1,5 @@
+{
+	"ignoredFiles": [
+		"test/resources/*"
+	]
+}
diff --git a/package.json b/package.json
index 0f0dda57ad1a406edea5629585d59f3b70fe8b9e..d5b85fc8ca7e0bed9970e3a4c71eb68022a539a2 100644
--- a/package.json
+++ b/package.json
@@ -180,6 +180,7 @@
 		"portscanner": "2.2.0",
 		"postcss-loader": "3.0.0",
 		"prismjs": "1.18.0",
+		"probe-image-size": "5.0.0",
 		"progress-bar-webpack-plugin": "1.12.1",
 		"promise-limit": "2.7.0",
 		"promise-sequential": "1.1.1",
diff --git a/src/@types/probe-image-size.d.ts b/src/@types/probe-image-size.d.ts
new file mode 100644
index 0000000000000000000000000000000000000000..665edcf2e73c7dd8220888f96a0014d4e4b39850
--- /dev/null
+++ b/src/@types/probe-image-size.d.ts
@@ -0,0 +1,27 @@
+declare module 'probe-image-size' {
+	import { ReadStream } from 'fs';
+
+	type ProbeOptions = {
+		retries: 1;
+		timeout: 30000;
+	};
+
+	type ProbeResult = {
+		width: number;
+		height: number;
+		length?: number;
+		type: string;
+		mime: string;
+		wUnits: 'in' | 'mm' | 'cm' | 'pt' | 'pc' | 'px' | 'em' | 'ex';
+		hUnits: 'in' | 'mm' | 'cm' | 'pt' | 'pc' | 'px' | 'em' | 'ex';
+		url?: string;
+	};
+
+	function probeImageSize(src: string | ReadStream, options?: ProbeOptions): Promise<ProbeResult>;
+	function probeImageSize(src: string | ReadStream, callback: (err: Error | null, result?: ProbeResult) => void): void;
+	function probeImageSize(src: string | ReadStream, options: ProbeOptions, callback: (err: Error | null, result?: ProbeResult) => void): void;
+
+	namespace probeImageSize {} // Hack
+
+	export = probeImageSize;
+}
diff --git a/src/misc/check-svg.ts b/src/misc/check-svg.ts
deleted file mode 100644
index 8ddeefede98d1ca4da267d5a19be23638cc41db3..0000000000000000000000000000000000000000
--- a/src/misc/check-svg.ts
+++ /dev/null
@@ -1,12 +0,0 @@
-import * as fs from 'fs';
-import isSvg from 'is-svg';
-
-export default function(path: string) {
-	try {
-		const size = fs.statSync(path).size;
-		if (size > 1 * 1024 * 1024) return false;
-		return isSvg(fs.readFileSync(path));
-	} catch {
-		return false;
-	}
-}
diff --git a/src/misc/detect-mine.ts b/src/misc/detect-mine.ts
deleted file mode 100644
index f47f127353d83c72fc9894c66403f8eba66e5168..0000000000000000000000000000000000000000
--- a/src/misc/detect-mine.ts
+++ /dev/null
@@ -1,31 +0,0 @@
-import * as fs from 'fs';
-import checkSvg from '../misc/check-svg';
-const FileType = require('file-type');
-
-export async function detectMine(path: string) {
-	return new Promise<[string, string | null]>((res, rej) => {
-		const readable = fs.createReadStream(path);
-		readable
-			.on('error', rej)
-			.once('data', async (buffer: Buffer) => {
-				readable.destroy();
-				const type = await FileType.fromBuffer(buffer);
-				if (type) {
-					if (type.mime == 'application/xml' && checkSvg(path)) {
-						res(['image/svg+xml', 'svg']);
-					} else {
-						res([type.mime, type.ext]);
-					}
-				} else if (checkSvg(path)) {
-					res(['image/svg+xml', 'svg']);
-				} else {
-					// 種類が同定できなかったら application/octet-stream にする
-					res(['application/octet-stream', null]);
-				}
-			})
-			.on('end', () => {
-				// maybe 0 bytes
-				res(['application/octet-stream', null]);
-			});
-	});
-}
diff --git a/src/misc/detect-url-mine.ts b/src/misc/detect-url-mime.ts
similarity index 57%
rename from src/misc/detect-url-mine.ts
rename to src/misc/detect-url-mime.ts
index eef64cfc564f45adfc9e48e819ff04c7fbc0653b..8d71cd01375d74b65bd59daae69950eac062c3de 100644
--- a/src/misc/detect-url-mine.ts
+++ b/src/misc/detect-url-mime.ts
@@ -1,14 +1,14 @@
 import { createTemp } from './create-temp';
 import { downloadUrl } from './donwload-url';
-import { detectMine } from './detect-mine';
+import { detectType } from './get-file-info';
 
-export async function detectUrlMine(url: string) {
+export async function detectUrlMime(url: string) {
 	const [path, cleanup] = await createTemp();
 
 	try {
 		await downloadUrl(url, path);
-		const [type] = await detectMine(path);
-		return type;
+		const { mime } = await detectType(path);
+		return mime;
 	} finally {
 		cleanup();
 	}
diff --git a/src/misc/get-file-info.ts b/src/misc/get-file-info.ts
new file mode 100644
index 0000000000000000000000000000000000000000..5ccb2802608f11fc41258808fb6cad2181fd92b2
--- /dev/null
+++ b/src/misc/get-file-info.ts
@@ -0,0 +1,201 @@
+import * as fs from 'fs';
+import * as crypto from 'crypto';
+import * as fileType from 'file-type';
+import isSvg from 'is-svg';
+import * as probeImageSize from 'probe-image-size';
+import * as sharp from 'sharp';
+
+export type FileInfo = {
+	size: number;
+	md5: string;
+	type: {
+		mime: string;
+		ext: string | null;
+	};
+	width?: number;
+	height?: number;
+	avgColor?: number[];
+	warnings: string[];
+};
+
+const TYPE_OCTET_STREAM = {
+	mime: 'application/octet-stream',
+	ext: null
+};
+
+const TYPE_SVG = {
+	mime: 'image/svg+xml',
+	ext: 'svg'
+};
+
+/**
+ * Get file information
+ */
+export async function getFileInfo(path: string): Promise<FileInfo> {
+	const warnings = [] as string[];
+
+	const size = await getFileSize(path);
+	const md5 = await calcHash(path);
+
+	let type = await detectType(path);
+
+	// image dimensions
+	let width: number | undefined;
+	let height: number | undefined;
+
+	if (['image/jpeg', 'image/gif', 'image/png', 'image/apng', 'image/webp', 'image/bmp', 'image/tiff', 'image/svg+xml', 'image/vnd.adobe.photoshop'].includes(type.mime)) {
+		const imageSize = await detectImageSize(path).catch(e => {
+			warnings.push(`detectImageSize failed: ${e}`);
+			return undefined;
+		});
+
+		// うまく判定できない画像は octet-stream にする
+		if (!imageSize) {
+			warnings.push(`cannot detect image dimensions`);
+			type = TYPE_OCTET_STREAM;
+		} else if (imageSize.wUnits === 'px') {
+			width = imageSize.width;
+			height = imageSize.height;
+
+			// 制限を超えている画像は octet-stream にする
+			if (imageSize.width > 16383 || imageSize.height > 16383) {
+				warnings.push(`image dimensions exceeds limits`);
+				type = TYPE_OCTET_STREAM;
+			}
+		} else {
+			warnings.push(`unsupported unit type: ${imageSize.wUnits}`);
+		}
+	}
+
+	// average color
+	let avgColor: number[] | undefined;
+
+	if (['image/jpeg', 'image/gif', 'image/png', 'image/apng', 'image/webp', 'image/svg+xml'].includes(type.mime)) {
+		avgColor = await calcAvgColor(path).catch(e => {
+			warnings.push(`calcAvgColor failed: ${e}`);
+			return undefined;
+		});
+	}
+
+	return {
+		size,
+		md5,
+		type,
+		width,
+		height,
+		avgColor,
+		warnings,
+	};
+}
+
+/**
+ * Detect MIME Type and extension
+ */
+export async function detectType(path: string) {
+	// Check 0 byte
+	const fileSize = await getFileSize(path);
+	if (fileSize === 0) {
+		return TYPE_OCTET_STREAM;
+	}
+
+	const type = await fileType.fromFile(path);
+
+	if (type) {
+		// XMLはSVGかもしれない
+		if (type.mime === 'application/xml' && await checkSvg(path)) {
+			return TYPE_SVG;
+		}
+
+		return {
+			mime: type.mime,
+			ext: type.ext
+		};
+	}
+
+	// 種類が不明でもSVGかもしれない
+	if (await checkSvg(path)) {
+		return TYPE_SVG;
+	}
+
+	// それでも種類が不明なら application/octet-stream にする
+	return TYPE_OCTET_STREAM;
+}
+
+/**
+ * Check the file is SVG or not
+ */
+export async function checkSvg(path: string) {
+	try {
+		const size = await getFileSize(path);
+		if (size > 1 * 1024 * 1024) return false;
+		return isSvg(fs.readFileSync(path));
+	} catch {
+		return false;
+	}
+}
+
+/**
+ * Get file size
+ */
+export async function getFileSize(path: string): Promise<number> {
+	return new Promise<number>((res, rej) => {
+		fs.stat(path, (err, stats) => {
+			if (err) return rej(err);
+			res(stats.size);
+		});
+	});
+}
+
+/**
+ * Calculate MD5 hash
+ */
+async function calcHash(path: string): Promise<string> {
+	return new Promise<string>((res, rej) => {
+		const readable = fs.createReadStream(path);
+		const hash = crypto.createHash('md5');
+		const chunks: Buffer[] = [];
+		readable
+			.on('error', rej)
+			.pipe(hash)
+			.on('error', rej)
+			.on('data', chunk => chunks.push(chunk))
+			.on('end', () => {
+				const buffer = Buffer.concat(chunks);
+				res(buffer.toString('hex'));
+			});
+	});
+}
+
+/**
+ * Detect dimensions of image
+ */
+async function detectImageSize(path: string): Promise<{
+	width: number;
+	height: number;
+	wUnits: string;
+	hUnits: string;
+}> {
+	const readable = fs.createReadStream(path);
+	const imageSize = await probeImageSize(readable);
+	readable.destroy();
+	return imageSize;
+}
+
+/**
+ * Calculate average color of image
+ */
+async function calcAvgColor(path: string): Promise<number[]> {
+	const img = sharp(path);
+
+	const info = await (img as any).stats();
+
+	if (info.isOpaque) {
+		const r = Math.round(info.channels[0].mean);
+		const g = Math.round(info.channels[1].mean);
+		const b = Math.round(info.channels[2].mean);
+
+		return [r, g, b];
+	} else {
+		return [255, 255, 255];
+	}
+}
diff --git a/src/server/api/endpoints/admin/emoji/add.ts b/src/server/api/endpoints/admin/emoji/add.ts
index 5345876da818c99920b16ce10db831f89eb77d2f..3a17760e53039ca3b696d416eb443f3e615c9512 100644
--- a/src/server/api/endpoints/admin/emoji/add.ts
+++ b/src/server/api/endpoints/admin/emoji/add.ts
@@ -1,6 +1,6 @@
 import $ from 'cafy';
 import define from '../../../define';
-import { detectUrlMine } from '../../../../../misc/detect-url-mine';
+import { detectUrlMime } from '../../../../../misc/detect-url-mime';
 import { Emojis } from '../../../../../models';
 import { genId } from '../../../../../misc/gen-id';
 import { getConnection } from 'typeorm';
@@ -46,7 +46,7 @@ export const meta = {
 };
 
 export default define(meta, async (ps, me) => {
-	const type = await detectUrlMine(ps.url);
+	const type = await detectUrlMime(ps.url);
 
 	const exists = await Emojis.findOne({
 		name: ps.name,
diff --git a/src/server/api/endpoints/admin/emoji/update.ts b/src/server/api/endpoints/admin/emoji/update.ts
index f4a01a3976bce39cad8e1371385d218eb7458a71..0651b8d2835a48ed1c26b736bf337e9314bb99c2 100644
--- a/src/server/api/endpoints/admin/emoji/update.ts
+++ b/src/server/api/endpoints/admin/emoji/update.ts
@@ -1,6 +1,6 @@
 import $ from 'cafy';
 import define from '../../../define';
-import { detectUrlMine } from '../../../../../misc/detect-url-mine';
+import { detectUrlMime } from '../../../../../misc/detect-url-mime';
 import { ID } from '../../../../../misc/cafy-id';
 import { Emojis } from '../../../../../models';
 import { getConnection } from 'typeorm';
@@ -52,7 +52,7 @@ export default define(meta, async (ps) => {
 
 	if (emoji == null) throw new ApiError(meta.errors.noSuchEmoji);
 
-	const type = await detectUrlMine(ps.url);
+	const type = await detectUrlMime(ps.url);
 
 	await Emojis.update(emoji.id, {
 		updatedAt: new Date(),
diff --git a/src/server/file/send-drive-file.ts b/src/server/file/send-drive-file.ts
index 22834357942aa4a1886d2b1cf6b960eaa53500cb..0b14378589fc10a8846500d3cfe1610930643cc4 100644
--- a/src/server/file/send-drive-file.ts
+++ b/src/server/file/send-drive-file.ts
@@ -8,7 +8,7 @@ import { contentDisposition } from '../../misc/content-disposition';
 import { DriveFiles } from '../../models';
 import { InternalStorage } from '../../services/drive/internal-storage';
 import { downloadUrl } from '../../misc/donwload-url';
-import { detectMine } from '../../misc/detect-mine';
+import { detectType } from '../../misc/get-file-info';
 import { convertToJpeg, convertToPng } from '../../services/drive/image-processor';
 import { GenerateVideoThumbnail } from '../../services/drive/generate-video-thumbnail';
 
@@ -52,15 +52,15 @@ export default async function(ctx: Koa.Context) {
 			try {
 				await downloadUrl(file.uri, path);
 
-				const [type, ext] = await detectMine(path);
+				const { mime, ext } = await detectType(path);
 
 				const convertFile = async () => {
 					if (isThumbnail) {
-						if (['image/jpeg', 'image/webp'].includes(type)) {
+						if (['image/jpeg', 'image/webp'].includes(mime)) {
 							return await convertToJpeg(path, 498, 280);
-						} else if (['image/png'].includes(type)) {
+						} else if (['image/png'].includes(mime)) {
 							return await convertToPng(path, 498, 280);
-						} else if (type.startsWith('video/')) {
+						} else if (mime.startsWith('video/')) {
 							return await GenerateVideoThumbnail(path);
 						}
 					}
@@ -68,7 +68,7 @@ export default async function(ctx: Koa.Context) {
 					return {
 						data: fs.readFileSync(path),
 						ext,
-						type,
+						type: mime,
 					};
 				};
 
diff --git a/src/server/proxy/proxy-media.ts b/src/server/proxy/proxy-media.ts
index 232b7a09cd13b1132924ce6dac273a4a3b7cb802..6b90e999216f898fb2f89c919b79cefaf8698da0 100644
--- a/src/server/proxy/proxy-media.ts
+++ b/src/server/proxy/proxy-media.ts
@@ -4,7 +4,7 @@ import { serverLogger } from '..';
 import { IImage, convertToPng, convertToJpeg } from '../../services/drive/image-processor';
 import { createTemp } from '../../misc/create-temp';
 import { downloadUrl } from '../../misc/donwload-url';
-import { detectMine } from '../../misc/detect-mine';
+import { detectType } from '../../misc/get-file-info';
 
 export async function proxyMedia(ctx: Koa.Context) {
 	const url = 'url' in ctx.query ? ctx.query.url : 'https://' + ctx.params.url;
@@ -15,21 +15,21 @@ export async function proxyMedia(ctx: Koa.Context) {
 	try {
 		await downloadUrl(url, path);
 
-		const [type, ext] = await detectMine(path);
+		const { mime, ext } = await detectType(path);
 
-		if (!type.startsWith('image/')) throw 403;
+		if (!mime.startsWith('image/')) throw 403;
 
 		let image: IImage;
 
-		if ('static' in ctx.query && ['image/png', 'image/gif', 'image/apng', 'image/vnd.mozilla.apng'].includes(type)) {
+		if ('static' in ctx.query && ['image/png', 'image/gif', 'image/apng', 'image/vnd.mozilla.apng'].includes(mime)) {
 			image = await convertToPng(path, 498, 280);
-		} else if ('preview' in ctx.query && ['image/jpeg', 'image/png', 'image/gif', 'image/apng', 'image/vnd.mozilla.apng'].includes(type)) {
+		} else if ('preview' in ctx.query && ['image/jpeg', 'image/png', 'image/gif', 'image/apng', 'image/vnd.mozilla.apng'].includes(mime)) {
 			image = await convertToJpeg(path, 200, 200);
 		} else {
 			image = {
 				data: fs.readFileSync(path),
 				ext,
-				type,
+				type: mime,
 			};
 		}
 
diff --git a/src/services/drive/add-file.ts b/src/services/drive/add-file.ts
index 350e4dfe19d17fbc389b70a0d1a6cc4ec3660521..7cc710c8b69cfb69131eb8b3d7353d88bf4ba9cb 100644
--- a/src/services/drive/add-file.ts
+++ b/src/services/drive/add-file.ts
@@ -1,9 +1,6 @@
-import { Buffer } from 'buffer';
 import * as fs from 'fs';
 
-import * as crypto from 'crypto';
 import { v4 as uuid } from 'uuid';
-import * as sharp from 'sharp';
 
 import { publishMainStream, publishDriveStream } from '../stream';
 import { deleteFile } from './delete-file';
@@ -12,7 +9,7 @@ import { GenerateVideoThumbnail } from './generate-video-thumbnail';
 import { driveLogger } from './logger';
 import { IImage, convertToJpeg, convertToWebp, convertToPng } from './image-processor';
 import { contentDisposition } from '../../misc/content-disposition';
-import { detectMine } from '../../misc/detect-mine';
+import { getFileInfo } from '../../misc/get-file-info';
 import { DriveFiles, DriveFolders, Users, Instances, UserProfiles } from '../../models';
 import { InternalStorage } from './internal-storage';
 import { DriveFile } from '../../models/entities/drive-file';
@@ -271,41 +268,16 @@ export default async function(
 	uri: string | null = null,
 	sensitive: boolean | null = null
 ): Promise<DriveFile> {
-	// Calc md5 hash
-	const calcHash = new Promise<string>((res, rej) => {
-		const readable = fs.createReadStream(path);
-		const hash = crypto.createHash('md5');
-		const chunks: Buffer[] = [];
-		readable
-			.on('error', rej)
-			.pipe(hash)
-			.on('error', rej)
-			.on('data', chunk => chunks.push(chunk))
-			.on('end', () => {
-				const buffer = Buffer.concat(chunks);
-				res(buffer.toString('hex'));
-			});
-	});
-
-	// Get file size
-	const getFileSize = new Promise<number>((res, rej) => {
-		fs.stat(path, (err, stats) => {
-			if (err) return rej(err);
-			res(stats.size);
-		});
-	});
-
-	const [hash, [mime, ext], size] = await Promise.all([calcHash, detectMine(path), getFileSize]);
-
-	logger.info(`hash: ${hash}, mime: ${mime}, ext: ${ext}, size: ${size}`);
+	const info = await getFileInfo(path);
+	logger.info(`${JSON.stringify(info)}`);
 
 	// detect name
-	const detectedName = name || (ext ? `untitled.${ext}` : 'untitled');
+	const detectedName = name || (info.type.ext ? `untitled.${info.type.ext}` : 'untitled');
 
 	if (!force) {
 		// Check if there is a file with the same hash
 		const much = await DriveFiles.findOne({
-			md5: hash,
+			md5: info.md5,
 			userId: user.id,
 		});
 
@@ -325,7 +297,7 @@ export default async function(
 		logger.debug(`drive usage is ${usage} (max: ${driveCapacity})`);
 
 		// If usage limit exceeded
-		if (usage + size > driveCapacity) {
+		if (usage + info.size > driveCapacity) {
 			if (Users.isLocalUser(user)) {
 				throw new Error('no-free-space');
 			} else {
@@ -351,57 +323,24 @@ export default async function(
 		return driveFolder;
 	};
 
-	const properties: {[key: string]: any} = {};
-
-	let propPromises: Promise<void>[] = [];
-
-	const isImage = ['image/jpeg', 'image/gif', 'image/png', 'image/apng', 'image/vnd.mozilla.apng', 'image/webp', 'image/svg+xml'].includes(mime);
-
-	if (isImage) {
-		const img = sharp(path);
-
-		// Calc width and height
-		const calcWh = async () => {
-			logger.debug('calculating image width and height...');
+	const properties: {
+		width?: number;
+		height?: number;
+		avgColor?: string;
+	} = {};
 
-			// Calculate width and height
-			const meta = await img.metadata();
-
-			logger.debug(`image width and height is calculated: ${meta.width}, ${meta.height}`);
-
-			properties['width'] = meta.width;
-			properties['height'] = meta.height;
-		};
-
-		// Calc average color
-		const calcAvg = async () => {
-			logger.debug('calculating average color...');
-
-			try {
-				const info = await img.stats();
-
-				if (info.isOpaque) {
-					const r = Math.round(info.channels[0].mean);
-					const g = Math.round(info.channels[1].mean);
-					const b = Math.round(info.channels[2].mean);
-
-					logger.debug(`average color is calculated: ${r}, ${g}, ${b}`);
-
-					properties['avgColor'] = `rgb(${r},${g},${b})`;
-				} else {
-					logger.debug(`this image is not opaque so average color is 255, 255, 255`);
-
-					properties['avgColor'] = `rgb(255,255,255)`;
-				}
-			} catch (e) { }
-		};
+	if (info.width) {
+		properties['width'] = info.width;
+		properties['height'] = info.height;
+	}
 
-		propPromises = [calcWh(), calcAvg()];
+	if (info.avgColor) {
+		properties['avgColor'] = `rgb(${info.avgColor.join(',')}`;
 	}
 
 	const profile = await UserProfiles.findOne(user.id);
 
-	const [folder] = await Promise.all([fetchFolder(), Promise.all(propPromises)]);
+	const folder = await fetchFolder();
 
 	let file = new DriveFile();
 	file.id = genId();
@@ -436,9 +375,9 @@ export default async function(
 	if (isLink) {
 		try {
 			file.size = 0;
-			file.md5 = hash;
+			file.md5 = info.md5;
 			file.name = detectedName;
-			file.type = mime;
+			file.type = info.type.mime;
 			file.storedInternal = false;
 
 			file = await DriveFiles.save(file);
@@ -457,7 +396,7 @@ export default async function(
 			}
 		}
 	} else {
-		file = await (save(file, path, detectedName, mime, hash, size));
+		file = await (save(file, path, detectedName, info.type.mime, info.md5, info.size));
 	}
 
 	logger.succ(`drive file has been created ${file.id}`);
diff --git a/test/get-file-info.ts b/test/get-file-info.ts
new file mode 100644
index 0000000000000000000000000000000000000000..920df073828268d0796e5db5141464af1bf54968
--- /dev/null
+++ b/test/get-file-info.ts
@@ -0,0 +1,152 @@
+/*
+ * Tests for detection of file information
+ *
+ * How to run the tests:
+ * > TS_NODE_FILES=true npx mocha test/get-file-info.ts --require ts-node/register
+ *
+ * To specify test:
+ * > TS_NODE_FILES=true npx mocha test/get-file-info.ts --require ts-node/register -g 'test name'
+ */
+
+import * as assert from 'assert';
+import { async } from './utils';
+import { getFileInfo } from '../src/misc/get-file-info';
+
+describe('Get file info', () => {
+	it('Empty file', async (async () => {
+		const path = `${__dirname}/resources/emptyfile`;
+		const info = await getFileInfo(path);
+		delete info.warnings;
+		assert.deepStrictEqual(info, {
+			size: 0,
+			md5: 'd41d8cd98f00b204e9800998ecf8427e',
+			type: {
+				mime: 'application/octet-stream',
+				ext: null
+			},
+			width: undefined,
+			height: undefined,
+			avgColor: undefined
+		});
+	}));
+
+	it('Generic JPEG', async (async () => {
+		const path = `${__dirname}/resources/Lenna.jpg`;
+		const info = await getFileInfo(path);
+		delete info.warnings;
+		assert.deepStrictEqual(info, {
+			size: 25360,
+			md5: '091b3f259662aa31e2ffef4519951168',
+			type: {
+				mime: 'image/jpeg',
+				ext: 'jpg'
+			},
+			width: 512,
+			height: 512,
+			avgColor: [ 181, 99, 106 ]
+		});
+	}));
+
+	it('Generic APNG', async (async () => {
+		const path = `${__dirname}/resources/anime.png`;
+		const info = await getFileInfo(path);
+		delete info.warnings;
+		assert.deepStrictEqual(info, {
+			size: 1868,
+			md5: '08189c607bea3b952704676bb3c979e0',
+			type: {
+				mime: 'image/apng',
+				ext: 'apng'
+			},
+			width: 256,
+			height: 256,
+			avgColor: [ 249, 253, 250 ]
+		});
+	}));
+
+	it('Generic AGIF', async (async () => {
+		const path = `${__dirname}/resources/anime.gif`;
+		const info = await getFileInfo(path);
+		delete info.warnings;
+		assert.deepStrictEqual(info, {
+			size: 2248,
+			md5: '32c47a11555675d9267aee1a86571e7e',
+			type: {
+				mime: 'image/gif',
+				ext: 'gif'
+			},
+			width: 256,
+			height: 256,
+			avgColor: [ 249, 253, 250 ]
+		});
+	}));
+
+	it('PNG with alpha', async (async () => {
+		const path = `${__dirname}/resources/with-alpha.png`;
+		const info = await getFileInfo(path);
+		delete info.warnings;
+		assert.deepStrictEqual(info, {
+			size: 3772,
+			md5: 'f73535c3e1e27508885b69b10cf6e991',
+			type: {
+				mime: 'image/png',
+				ext: 'png'
+			},
+			width: 256,
+			height: 256,
+			avgColor: [ 255, 255, 255 ]
+		});
+	}));
+
+	it('Generic SVG', async (async () => {
+		const path = `${__dirname}/resources/image.svg`;
+		const info = await getFileInfo(path);
+		delete info.warnings;
+		assert.deepStrictEqual(info, {
+			size: 505,
+			md5: 'b6f52b4b021e7b92cdd04509c7267965',
+			type: {
+				mime: 'image/svg+xml',
+				ext: 'svg'
+			},
+			width: 256,
+			height: 256,
+			avgColor: [ 255, 255, 255 ]
+		});
+	}));
+
+	it('SVG with XML definition', async (async () => {
+		// https://github.com/syuilo/misskey/issues/4413
+		const path = `${__dirname}/resources/with-xml-def.svg`;
+		const info = await getFileInfo(path);
+		delete info.warnings;
+		assert.deepStrictEqual(info, {
+			size: 544,
+			md5: '4b7a346cde9ccbeb267e812567e33397',
+			type: {
+				mime: 'image/svg+xml',
+				ext: 'svg'
+			},
+			width: 256,
+			height: 256,
+			avgColor: [ 255, 255, 255 ]
+		});
+	}));
+
+	it('Dimension limit', async (async () => {
+		const path = `${__dirname}/resources/25000x25000.png`;
+		const info = await getFileInfo(path);
+		delete info.warnings;
+		assert.deepStrictEqual(info, {
+			size: 75933,
+			md5: '268c5dde99e17cf8fe09f1ab3f97df56',
+			type: {
+				mime: 'application/octet-stream',	// do not treat as image
+				ext: null
+			},
+			width: 25000,
+			height: 25000,
+			avgColor: undefined
+		});
+	}));
+});
diff --git a/test/resources/25000x25000.png b/test/resources/25000x25000.png
new file mode 100644
index 0000000000000000000000000000000000000000..0ed4666925f715eca6fdd9831206ec478b304047
Binary files /dev/null and b/test/resources/25000x25000.png differ
diff --git a/test/resources/anime.gif b/test/resources/anime.gif
new file mode 100644
index 0000000000000000000000000000000000000000..256ba495ce11b5f1ec7649c739feb750844eb4df
Binary files /dev/null and b/test/resources/anime.gif differ
diff --git a/test/resources/anime.png b/test/resources/anime.png
new file mode 100644
index 0000000000000000000000000000000000000000..f13600f7a49951d0bd67cd0c8c34c06379b6a4cf
Binary files /dev/null and b/test/resources/anime.png differ
diff --git a/test/resources/emptyfile b/test/resources/emptyfile
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391
diff --git a/test/resources/with-alpha.png b/test/resources/with-alpha.png
new file mode 100644
index 0000000000000000000000000000000000000000..adc8d01805dbcf1bf38f506096b99bc157f25de5
Binary files /dev/null and b/test/resources/with-alpha.png differ
diff --git a/test/resources/with-xml-def.svg b/test/resources/with-xml-def.svg
new file mode 100644
index 0000000000000000000000000000000000000000..90971215a64a6ad9e0e48aed2d72c98a881dcf70
Binary files /dev/null and b/test/resources/with-xml-def.svg differ
diff --git a/yarn.lock b/yarn.lock
index d6208cc76bd48728044b44699d96660fd9fae651..764d48cbeca017da8e69aa6ddca128f4058676cf 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3038,6 +3038,13 @@ debug-fabulous@1.X:
     memoizee "0.4.X"
     object-assign "4.X"
 
+debug@2, debug@^2.2.0, debug@^2.3.3, debug@^2.5.2:
+  version "2.6.9"
+  resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.9.tgz#5d128515df134ff327e90a4c93f4e077a536341f"
+  integrity sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==
+  dependencies:
+    ms "2.0.0"
+
 debug@3.1.0, debug@~3.1.0:
   version "3.1.0"
   resolved "https://registry.yarnpkg.com/debug/-/debug-3.1.0.tgz#5bb5a0672628b64149566ba16819e61518c67261"
@@ -3059,13 +3066,6 @@ debug@4, debug@^4.0.1, debug@^4.1.0, debug@^4.1.1:
   dependencies:
     ms "^2.1.1"
 
-debug@^2.2.0, debug@^2.3.3, debug@^2.5.2:
-  version "2.6.9"
-  resolved "https://registry.yarnpkg.com/debug/-/debug-2.6.9.tgz#5d128515df134ff327e90a4c93f4e077a536341f"
-  integrity sha512-bC7ElrdJaJnPbAP+1EotYvqZsb3ecl5wi6Bfi6BJTUcNowp6cvspg0jXznRTKDjm/E7AdgFBVeAPVMNcKGsHMA==
-  dependencies:
-    ms "2.0.0"
-
 debuglog@^1.0.0:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/debuglog/-/debuglog-1.0.1.tgz#aa24ffb9ac3df9a2351837cfb2d279360cd78492"
@@ -3110,7 +3110,7 @@ deep-is@~0.1.3:
   resolved "https://registry.yarnpkg.com/deep-is/-/deep-is-0.1.3.tgz#b369d6fb5dbc13eecf524f91b070feedc357cf34"
   integrity sha1-s2nW+128E+7PUk+RsHD+7cNXzzQ=
 
-deepmerge@^4.2.2:
+deepmerge@^4.0.0, deepmerge@^4.2.2:
   version "4.2.2"
   resolved "https://registry.yarnpkg.com/deepmerge/-/deepmerge-4.2.2.tgz#44d2ea3679b8f4d4ffba33f03d865fc1e7bf4955"
   integrity sha512-FJ3UgI4gIl+PHZm53knsuSFpE+nESMr7M4v9QcgB7S63Kj/6WqMiFQJpBBYz1Pt+66bZpP3Q7Lye0Oo9MPKEdg==
@@ -8040,6 +8040,17 @@ prismjs@1.18.0:
   optionalDependencies:
     clipboard "^2.0.0"
 
+probe-image-size@5.0.0:
+  version "5.0.0"
+  resolved "https://registry.yarnpkg.com/probe-image-size/-/probe-image-size-5.0.0.tgz#1b87d20340ab8fcdb4324ec77fbc8a5f53419878"
+  integrity sha512-V6uBYw5eBc5UVIE7MUZD6Nxg0RYuGDWLDenEn0B1WC6PcTvn1xdQ6HLDDuznefsiExC6rNrCz7mFRBo0f3Xekg==
+  dependencies:
+    deepmerge "^4.0.0"
+    inherits "^2.0.3"
+    next-tick "^1.0.0"
+    request "^2.83.0"
+    stream-parser "~0.3.1"
+
 process-nextick-args@^2.0.0, process-nextick-args@~2.0.0:
   version "2.0.1"
   resolved "https://registry.yarnpkg.com/process-nextick-args/-/process-nextick-args-2.0.1.tgz#7820d9b16120cc55ca9ae7792680ae7dba6d7fe2"
@@ -8652,7 +8663,7 @@ request-stats@3.0.0:
     http-headers "^3.0.1"
     once "^1.4.0"
 
-request@2.88.0, request@^2.73.0, request@^2.88.0:
+request@2.88.0, request@^2.73.0, request@^2.83.0, request@^2.88.0:
   version "2.88.0"
   resolved "https://registry.yarnpkg.com/request/-/request-2.88.0.tgz#9c2fca4f7d35b592efe57c7f0a55e81052124fef"
   integrity sha512-NAqBSrijGLZdM0WZNsInLJpkJokL72XYjUpnB0iwsRgxh7dB6COrHnTBNwN0E+lHDAJzu7kLAkDeY08z2/A0hg==
@@ -9356,6 +9367,13 @@ stream-http@^2.7.2:
     to-arraybuffer "^1.0.0"
     xtend "^4.0.0"
 
+stream-parser@~0.3.1:
+  version "0.3.1"
+  resolved "https://registry.yarnpkg.com/stream-parser/-/stream-parser-0.3.1.tgz#1618548694420021a1182ff0af1911c129761773"
+  integrity sha1-FhhUhpRCACGhGC/wrxkRwSl2F3M=
+  dependencies:
+    debug "2"
+
 stream-shift@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/stream-shift/-/stream-shift-1.0.0.tgz#d5c752825e5367e786f78e18e445ea223a155952"