From ed60942717c22e2c0708fc1c71effc0a0d9c05fa Mon Sep 17 00:00:00 2001
From: kakkokari-gtyih <67428053+kakkokari-gtyih@users.noreply.github.com>
Date: Sat, 24 May 2025 19:48:24 +0900
Subject: [PATCH] enhance: refine uploadFile

---
 .../src/components/MkFormDialog.file.vue      |  5 +-
 .../frontend/src/components/MkPostForm.vue    |  8 ++-
 .../src/components/MkUploaderDialog.vue       | 72 +++++++++++++++----
 .../components/MkWatermarkEditorDialog.vue    |  9 ++-
 packages/frontend/src/os.ts                   |  3 +
 .../custom-emojis-manager.local.list.vue      |  5 +-
 .../frontend/src/pages/channel-editor.vue     |  5 +-
 .../frontend/src/pages/chat/room.form.vue     |  6 +-
 .../src/pages/custom-emojis-manager.vue       |  5 +-
 .../frontend/src/pages/emoji-edit-dialog.vue  |  5 +-
 packages/frontend/src/pages/gallery/edit.vue  |  7 +-
 .../src/pages/page-editor/page-editor.vue     |  5 +-
 .../src/pages/settings/account-data.vue       | 25 +++++--
 packages/frontend/src/pages/settings/deck.vue |  5 +-
 .../src/pages/settings/sounds.sound.vue       |  4 +-
 packages/frontend/src/utility/drive.ts        | 24 +++++--
 packages/frontend/src/utility/watermark.ts    | 10 ++-
 17 files changed, 161 insertions(+), 42 deletions(-)

diff --git a/packages/frontend/src/components/MkFormDialog.file.vue b/packages/frontend/src/components/MkFormDialog.file.vue
index a11075c342..182ff3ccf5 100644
--- a/packages/frontend/src/components/MkFormDialog.file.vue
+++ b/packages/frontend/src/components/MkFormDialog.file.vue
@@ -51,7 +51,10 @@ if (props.fileId) {
 }
 
 function selectButton(ev: MouseEvent) {
-	selectFile(ev.currentTarget ?? ev.target).then(async (file) => {
+	selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: false,
+	}).then(async (file) => {
 		if (!file) return;
 		if (props.validate && !await props.validate(file)) return;
 
diff --git a/packages/frontend/src/components/MkPostForm.vue b/packages/frontend/src/components/MkPostForm.vue
index 982ed88003..cd4fabea02 100644
--- a/packages/frontend/src/components/MkPostForm.vue
+++ b/packages/frontend/src/components/MkPostForm.vue
@@ -120,7 +120,7 @@ import { formatTimeString } from '@/utility/format-time-string.js';
 import { Autocomplete } from '@/utility/autocomplete.js';
 import * as os from '@/os.js';
 import { misskeyApi } from '@/utility/misskey-api.js';
-import { selectFiles } from '@/utility/drive.js';
+import { selectFile } from '@/utility/drive.js';
 import { store } from '@/store.js';
 import MkInfo from '@/components/MkInfo.vue';
 import { i18n } from '@/i18n.js';
@@ -437,7 +437,11 @@ function focus() {
 function chooseFileFrom(ev) {
 	if (props.mock) return;
 
-	selectFiles(ev.currentTarget ?? ev.target, i18n.ts.attachFile).then(files_ => {
+	selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: true,
+		label: i18n.ts.attachFile,
+	}).then(files_ => {
 		for (const file of files_) {
 			files.value.push(file);
 		}
diff --git a/packages/frontend/src/components/MkUploaderDialog.vue b/packages/frontend/src/components/MkUploaderDialog.vue
index 3f5f0776a8..a3f5c14ae1 100644
--- a/packages/frontend/src/components/MkUploaderDialog.vue
+++ b/packages/frontend/src/components/MkUploaderDialog.vue
@@ -92,6 +92,13 @@ SPDX-License-Identifier: AGPL-3.0-only
 </MkModalWindow>
 </template>
 
+<script lang="ts">
+export type UploaderDialogFeatures = {
+	watermark?: boolean;
+	crop?: boolean;
+};
+</script>
+
 <script lang="ts" setup>
 import { computed, markRaw, onMounted, ref, useTemplateRef, watch } from 'vue';
 import * as Misskey from 'misskey-js';
@@ -107,6 +114,7 @@ import bytes from '@/filters/bytes.js';
 import MkSelect from '@/components/MkSelect.vue';
 import { isWebpSupported } from '@/utility/isWebpSupported.js';
 import { uploadFile, UploadAbortedError } from '@/utility/drive.js';
+import { canApplyWatermark, getWatermarkAppliedImage } from '@/utility/watermark.js';
 import * as os from '@/os.js';
 import { ensureSignin } from '@/i.js';
 
@@ -119,7 +127,7 @@ const COMPRESSION_SUPPORTED_TYPES = [
 	'image/svg+xml',
 ];
 
-const CROPPING_SUPPORTED_TYPES = [
+const IMGEDIT_SUPPORTED_TYPES = [
 	'image/jpeg',
 	'image/png',
 	'image/webp',
@@ -135,10 +143,18 @@ const props = withDefaults(defineProps<{
 	files: File[];
 	folderId?: string | null;
 	multiple?: boolean;
+	features?: UploaderDialogFeatures;
 }>(), {
 	multiple: true,
 });
 
+const uploaderFeatures = computed<Required<UploaderDialogFeatures>>(() => {
+	return {
+		watermark: props.features?.watermark ?? true,
+		crop: props.features?.crop ?? true,
+	};
+});
+
 const emit = defineEmits<{
 	(ev: 'done', driveFiles: Misskey.entities.DriveFile[]): void;
 	(ev: 'canceled'): void;
@@ -157,6 +173,7 @@ const items = ref<{
 	aborted: boolean;
 	compressedSize?: number | null;
 	compressedImage?: Blob | null;
+	applyWatermark?: boolean | null;
 	file: File;
 	abort?: (() => void) | null;
 }[]>([]);
@@ -274,19 +291,37 @@ function showMenu(ev: MouseEvent, item: typeof items.value[0]) {
 		},
 	});
 
-	if (CROPPING_SUPPORTED_TYPES.includes(item.file.type) && !item.waiting && !item.uploading && !item.uploaded) {
-		menu.push({
-			icon: 'ti ti-crop',
-			text: i18n.ts.cropImage,
-			action: async () => {
-				const cropped = await os.cropImageFile(item.file, { aspectRatio: null });
-				items.value.splice(items.value.indexOf(item), 1, {
-					...item,
-					file: markRaw(cropped),
-					thumbnail: window.URL.createObjectURL(cropped),
-				});
-			},
-		});
+	if (IMGEDIT_SUPPORTED_TYPES.includes(item.file.type) && !item.waiting && !item.uploading && !item.uploaded) {
+		if (uploaderFeatures.value.watermark) {
+			const _applyWatermark = computed({
+				get: () => item.applyWatermark ?? prefer.s.useWatermark,
+				set: (v) => {
+					item.applyWatermark = v;
+				},
+			});
+
+			menu.push({
+				icon: 'ti ti-ripple',
+				text: i18n.ts.useWatermark,
+				type: 'switch',
+				ref: _applyWatermark,
+			});
+		}
+
+		if (uploaderFeatures.value.crop) {
+			menu.push({
+				icon: 'ti ti-crop',
+				text: i18n.ts.cropImage,
+				action: async () => {
+					const cropped = await os.cropImageFile(item.file, { aspectRatio: null });
+					items.value.splice(items.value.indexOf(item), 1, {
+						...item,
+						file: markRaw(cropped),
+						thumbnail: window.URL.createObjectURL(cropped),
+					});
+				},
+			});
+		}
 	}
 
 	if (!item.waiting && !item.uploading && !item.uploaded) {
@@ -333,6 +368,15 @@ async function upload() { // エラーハンドリングなどを考慮してシ
 		item.waiting = true;
 		item.uploadFailed = false;
 
+		if (
+			item.applyWatermark === true &&
+			uploaderFeatures.value.watermark &&
+			IMGEDIT_SUPPORTED_TYPES.includes(item.file.type) &&
+			canApplyWatermark(prefer.s.watermarkConfig)
+		) {
+			item.file = await getWatermarkAppliedImage(item.file, prefer.s.watermarkConfig);
+		}
+
 		const shouldCompress = item.compressedImage == null && compressionLevel.value !== 0 && compressionSettings.value && COMPRESSION_SUPPORTED_TYPES.includes(item.file.type) && !(await isAnimated(item.file));
 
 		if (shouldCompress) {
diff --git a/packages/frontend/src/components/MkWatermarkEditorDialog.vue b/packages/frontend/src/components/MkWatermarkEditorDialog.vue
index a51428f437..a652f3e7bd 100644
--- a/packages/frontend/src/components/MkWatermarkEditorDialog.vue
+++ b/packages/frontend/src/components/MkWatermarkEditorDialog.vue
@@ -251,7 +251,14 @@ const friendlyFileName = computed<string>(() => {
 });
 
 function chooseFile(ev: MouseEvent) {
-	selectFile(ev.currentTarget ?? ev.target, i18n.ts.selectFile).then((file) => {
+	selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: false,
+		label: i18n.ts.selectFile,
+		features: {
+			watermark: false,
+		},
+	}).then((file) => {
 		if (!file.type.startsWith('image')) {
 			os.alert({
 				type: 'warning',
diff --git a/packages/frontend/src/os.ts b/packages/frontend/src/os.ts
index a513ae4902..4daf9adf43 100644
--- a/packages/frontend/src/os.ts
+++ b/packages/frontend/src/os.ts
@@ -13,6 +13,7 @@ import type { ComponentProps as CP } from 'vue-component-type-helpers';
 import type { Form, GetFormResultType } from '@/utility/form.js';
 import type { MenuItem } from '@/types/menu.js';
 import type { PostFormProps } from '@/types/post-form.js';
+import type { UploaderDialogFeatures } from '@/components/MkUploaderDialog.vue';
 import type MkRoleSelectDialog_TypeReferenceOnly from '@/components/MkRoleSelectDialog.vue';
 import type MkEmojiPickerDialog_TypeReferenceOnly from '@/components/MkEmojiPickerDialog.vue';
 import { misskeyApi } from '@/utility/misskey-api.js';
@@ -773,6 +774,7 @@ export function launchUploader(
 	options?: {
 		folderId?: string | null;
 		multiple?: boolean;
+		features?: UploaderDialogFeatures;
 	},
 ): Promise<Misskey.entities.DriveFile[]> {
 	return new Promise((res, rej) => {
@@ -781,6 +783,7 @@ export function launchUploader(
 			files: markRaw(files),
 			folderId: options?.folderId,
 			multiple: options?.multiple,
+			features: options?.features,
 		}, {
 			done: driveFiles => {
 				if (driveFiles.length === 0) return rej();
diff --git a/packages/frontend/src/pages/admin/custom-emojis-manager.local.list.vue b/packages/frontend/src/pages/admin/custom-emojis-manager.local.list.vue
index 68c7048ae1..172a4d09cc 100644
--- a/packages/frontend/src/pages/admin/custom-emojis-manager.local.list.vue
+++ b/packages/frontend/src/pages/admin/custom-emojis-manager.local.list.vue
@@ -174,7 +174,10 @@ function setupGrid(): GridSetting {
 			{
 				bindTo: 'url', icon: 'ti-icons', type: 'image', editable: true, width: 'auto', validators: [required],
 				async customValueEditor(row, col, value, cellElement) {
-					const file = await selectFile(cellElement);
+					const file = await selectFile({
+						anchorElement: cellElement,
+						multiple: false,
+					});
 					gridItems.value[row.index].url = file.url;
 					gridItems.value[row.index].fileId = file.id;
 
diff --git a/packages/frontend/src/pages/channel-editor.vue b/packages/frontend/src/pages/channel-editor.vue
index d9d9f0c188..72281ea882 100644
--- a/packages/frontend/src/pages/channel-editor.vue
+++ b/packages/frontend/src/pages/channel-editor.vue
@@ -188,7 +188,10 @@ async function archive() {
 }
 
 function setBannerImage(evt) {
-	selectFile(evt.currentTarget ?? evt.target).then(file => {
+	selectFile({
+		anchorElement: evt.currentTarget ?? evt.target,
+		multiple: false,
+	}).then(file => {
 		bannerId.value = file.id;
 	});
 }
diff --git a/packages/frontend/src/pages/chat/room.form.vue b/packages/frontend/src/pages/chat/room.form.vue
index 7e3be67230..17b68d6eb9 100644
--- a/packages/frontend/src/pages/chat/room.form.vue
+++ b/packages/frontend/src/pages/chat/room.form.vue
@@ -168,7 +168,11 @@ function onKeydown(ev: KeyboardEvent) {
 }
 
 function chooseFile(ev: MouseEvent) {
-	selectFile(ev.currentTarget ?? ev.target, i18n.ts.selectFile).then(selectedFile => {
+	selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: false,
+		label: i18n.ts.selectFile,
+	}).then(selectedFile => {
 		file.value = selectedFile;
 	});
 }
diff --git a/packages/frontend/src/pages/custom-emojis-manager.vue b/packages/frontend/src/pages/custom-emojis-manager.vue
index c2bc621f6a..4d78ff14be 100644
--- a/packages/frontend/src/pages/custom-emojis-manager.vue
+++ b/packages/frontend/src/pages/custom-emojis-manager.vue
@@ -214,7 +214,10 @@ const menu = (ev: MouseEvent) => {
 		icon: 'ti ti-upload',
 		text: i18n.ts.import,
 		action: async () => {
-			const file = await selectFile(ev.currentTarget ?? ev.target);
+			const file = await selectFile({
+				anchorElement: ev.currentTarget ?? ev.target,
+				multiple: false,
+			});
 			misskeyApi('admin/emoji/import-zip', {
 				fileId: file.id,
 			})
diff --git a/packages/frontend/src/pages/emoji-edit-dialog.vue b/packages/frontend/src/pages/emoji-edit-dialog.vue
index c47f0c91a9..b4fc4a46d9 100644
--- a/packages/frontend/src/pages/emoji-edit-dialog.vue
+++ b/packages/frontend/src/pages/emoji-edit-dialog.vue
@@ -121,7 +121,10 @@ watch(roleIdsThatCanBeUsedThisEmojiAsReaction, async () => {
 const imgUrl = computed(() => file.value ? file.value.url : props.emoji ? props.emoji.url : null);
 
 async function changeImage(ev: Event) {
-	file.value = await selectFile(ev.currentTarget ?? ev.target);
+	file.value = await selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: false,
+	});
 	const candidate = file.value.name.replace(/\.(.+)$/, '');
 	if (candidate.match(/^[a-z0-9_]+$/)) {
 		name.value = candidate;
diff --git a/packages/frontend/src/pages/gallery/edit.vue b/packages/frontend/src/pages/gallery/edit.vue
index 426be40c38..f4d528ac6e 100644
--- a/packages/frontend/src/pages/gallery/edit.vue
+++ b/packages/frontend/src/pages/gallery/edit.vue
@@ -44,7 +44,7 @@ import MkInput from '@/components/MkInput.vue';
 import MkTextarea from '@/components/MkTextarea.vue';
 import MkSwitch from '@/components/MkSwitch.vue';
 import FormSuspense from '@/components/form/suspense.vue';
-import { selectFiles } from '@/utility/drive.js';
+import { selectFile } from '@/utility/drive.js';
 import * as os from '@/os.js';
 import { misskeyApi } from '@/utility/misskey-api.js';
 import { definePage } from '@/page.js';
@@ -64,7 +64,10 @@ const title = ref<string | null>(null);
 const isSensitive = ref(false);
 
 function chooseFile(evt) {
-	selectFiles(evt.currentTarget ?? evt.target).then(selected => {
+	selectFile({
+		anchorElement: evt.currentTarget ?? evt.target,
+		multiple: false,
+	}).then(selected => {
 		files.value = files.value.concat(selected);
 	});
 }
diff --git a/packages/frontend/src/pages/page-editor/page-editor.vue b/packages/frontend/src/pages/page-editor/page-editor.vue
index 49d9150852..f2ffdf645a 100644
--- a/packages/frontend/src/pages/page-editor/page-editor.vue
+++ b/packages/frontend/src/pages/page-editor/page-editor.vue
@@ -205,7 +205,10 @@ async function add() {
 }
 
 function setEyeCatchingImage(img: Event) {
-	selectFile(img.currentTarget ?? img.target, null).then(file => {
+	selectFile({
+		anchorElement: img.currentTarget ?? img.target,
+		multiple: false,
+	}).then(file => {
 		eyeCatchingImageId.value = file.id;
 	});
 }
diff --git a/packages/frontend/src/pages/settings/account-data.vue b/packages/frontend/src/pages/settings/account-data.vue
index d175c0dc32..5a00d7a9d7 100644
--- a/packages/frontend/src/pages/settings/account-data.vue
+++ b/packages/frontend/src/pages/settings/account-data.vue
@@ -233,7 +233,10 @@ const exportAntennas = () => {
 };
 
 const importFollowing = async (ev) => {
-	const file = await selectFile(ev.currentTarget ?? ev.target);
+	const file = await selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: false,
+	});
 	misskeyApi('i/import-following', {
 		fileId: file.id,
 		withReplies: withReplies.value,
@@ -241,22 +244,34 @@ const importFollowing = async (ev) => {
 };
 
 const importUserLists = async (ev) => {
-	const file = await selectFile(ev.currentTarget ?? ev.target);
+	const file = await selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: false,
+	});
 	misskeyApi('i/import-user-lists', { fileId: file.id }).then(onImportSuccess).catch(onError);
 };
 
 const importMuting = async (ev) => {
-	const file = await selectFile(ev.currentTarget ?? ev.target);
+	const file = await selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: false,
+	});
 	misskeyApi('i/import-muting', { fileId: file.id }).then(onImportSuccess).catch(onError);
 };
 
 const importBlocking = async (ev) => {
-	const file = await selectFile(ev.currentTarget ?? ev.target);
+	const file = await selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: false,
+	});
 	misskeyApi('i/import-blocking', { fileId: file.id }).then(onImportSuccess).catch(onError);
 };
 
 const importAntennas = async (ev) => {
-	const file = await selectFile(ev.currentTarget ?? ev.target);
+	const file = await selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: false,
+	});
 	misskeyApi('i/import-antennas', { fileId: file.id }).then(onImportSuccess).catch(onError);
 };
 
diff --git a/packages/frontend/src/pages/settings/deck.vue b/packages/frontend/src/pages/settings/deck.vue
index 22bd8cbc80..ae882d1ee2 100644
--- a/packages/frontend/src/pages/settings/deck.vue
+++ b/packages/frontend/src/pages/settings/deck.vue
@@ -114,7 +114,10 @@ watch(wallpaper, async () => {
 });
 
 function setWallpaper(ev: MouseEvent) {
-	selectFile(ev.currentTarget ?? ev.target, null).then(file => {
+	selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: false,
+	}).then(file => {
 		wallpaper.value = file.url;
 	});
 }
diff --git a/packages/frontend/src/pages/settings/sounds.sound.vue b/packages/frontend/src/pages/settings/sounds.sound.vue
index e64d26dd30..7aad43b1d0 100644
--- a/packages/frontend/src/pages/settings/sounds.sound.vue
+++ b/packages/frontend/src/pages/settings/sounds.sound.vue
@@ -94,7 +94,9 @@ const friendlyFileName = computed<string>(() => {
 });
 
 function selectSound(ev) {
-	selectFile(ev.currentTarget ?? ev.target, {
+	selectFile({
+		anchorElement: ev.currentTarget ?? ev.target,
+		multiple: false,
 		label: i18n.ts._soundSettings.driveFile,
 	}).then(async (file) => {
 		if (!file.type.startsWith('audio')) {
diff --git a/packages/frontend/src/utility/drive.ts b/packages/frontend/src/utility/drive.ts
index f171a4d14d..3ddee43537 100644
--- a/packages/frontend/src/utility/drive.ts
+++ b/packages/frontend/src/utility/drive.ts
@@ -15,6 +15,7 @@ import { $i } from '@/i.js';
 import { instance } from '@/instance.js';
 import { globalEvents } from '@/events.js';
 import { getProxiedImageUrl } from '@/utility/media-proxy.js';
+import type { UploaderDialogFeatures } from '@/components/MkUploaderDialog.vue';
 
 type UploadReturnType = {
 	filePromise: Promise<Misskey.entities.DriveFile>;
@@ -154,6 +155,7 @@ export function uploadFile(file: File | Blob, options: {
 export function chooseFileFromPcAndUpload(
 	options: {
 		multiple?: boolean;
+		features?: UploaderDialogFeatures;
 		folderId?: string | null;
 	} = {},
 ): Promise<Misskey.entities.DriveFile[]> {
@@ -162,6 +164,7 @@ export function chooseFileFromPcAndUpload(
 			if (files.length === 0) return;
 			os.launchUploader(files, {
 				folderId: options.folderId,
+				features: options.features,
 			}).then(driveFiles => {
 				res(driveFiles);
 			});
@@ -220,7 +223,7 @@ export function chooseFileFromUrl(): Promise<Misskey.entities.DriveFile> {
 	});
 }
 
-function select(anchorElement: HTMLElement | EventTarget | null, label: string | null, multiple: boolean): Promise<Misskey.entities.DriveFile[]> {
+function select(anchorElement: HTMLElement | EventTarget | null, label: string | null, multiple: boolean, features?: UploaderDialogFeatures): Promise<Misskey.entities.DriveFile[]> {
 	return new Promise((res, rej) => {
 		os.popupMenu([label ? {
 			text: label,
@@ -228,7 +231,7 @@ function select(anchorElement: HTMLElement | EventTarget | null, label: string |
 		} : undefined, {
 			text: i18n.ts.upload,
 			icon: 'ti ti-upload',
-			action: () => chooseFileFromPcAndUpload({ multiple }).then(files => res(files)),
+			action: () => chooseFileFromPcAndUpload({ multiple, features }).then(files => res(files)),
 		}, {
 			text: i18n.ts.fromDrive,
 			icon: 'ti ti-cloud',
@@ -241,12 +244,19 @@ function select(anchorElement: HTMLElement | EventTarget | null, label: string |
 	});
 }
 
-export function selectFile(anchorElement: HTMLElement | EventTarget | null, label: string | null = null): Promise<Misskey.entities.DriveFile> {
-	return select(anchorElement, label, false).then(files => files[0]);
-}
+type SelectFileOptions<M extends boolean> = {
+	anchorElement: HTMLElement | EventTarget | null;
+	multiple: M;
+	label?: string | null;
+	features?: UploaderDialogFeatures;
+};
 
-export function selectFiles(anchorElement: HTMLElement | EventTarget | null, label: string | null = null): Promise<Misskey.entities.DriveFile[]> {
-	return select(anchorElement, label, true);
+export async function selectFile<
+	M extends boolean,
+	MR extends M extends true ? Misskey.entities.DriveFile[] : Misskey.entities.DriveFile
+>(opts: SelectFileOptions<M>): Promise<MR> {
+	const files = await select(opts.anchorElement, opts.label ?? null, opts.multiple ?? false, opts.features);
+	return opts.multiple ? (files as MR) : (files[0]! as MR);
 }
 
 export async function createCroppedImageDriveFileFromImageDriveFile(imageDriveFile: Misskey.entities.DriveFile, options: {
diff --git a/packages/frontend/src/utility/watermark.ts b/packages/frontend/src/utility/watermark.ts
index 48608f62b4..5901a04b07 100644
--- a/packages/frontend/src/utility/watermark.ts
+++ b/packages/frontend/src/utility/watermark.ts
@@ -294,8 +294,14 @@ export function applyWatermark(img: string | Blob, el: HTMLCanvasElement | Offsc
  * @param config ウォーターマークの設定
  * @returns ウォーターマークを適用した画像のBlob
  */
-export async function getWatermarkAppliedImage(img: Blob, config: WatermarkConfig): Promise<Blob> {
+export async function getWatermarkAppliedImage<F extends Blob | File>(img: F, config: WatermarkConfig): Promise<F> {
 	const canvas = window.document.createElement('canvas');
 	await applyWatermark(img, canvas, config);
-	return new Promise(resolve => canvas.toBlob(blob => resolve(blob!)));
+	return new Promise(resolve => canvas.toBlob(blob => {
+		if (img instanceof File) {
+			resolve(new File([blob!], img.name) as F);
+		} else {
+			resolve(blob as F);
+		}
+	}, img.type || 'image/png'));
 }