diff --git a/src/config.ts b/src/config.ts
index be66299..80d622ce 100644
--- a/src/config.ts
+++ b/src/config.ts
@@ -1,5 +1,5 @@
 import { Computed, Dict, Schema, Session, Time } from 'koishi'
-import { Size } from './utils'
+import { ALLOWED_TYPES, Size } from './utils'
 
 const options: Computed.Options = {
   userFields: ['authority'],
@@ -183,10 +183,14 @@ export interface PromptConfig {
   translator?: boolean
   lowerCase?: boolean
   maxWords?: Computed<number>
+  allowedInputImageTypes?: Computed<string[]>
+  transformPromptSyntax?: Computed<boolean>
 }
 
 export const PromptConfig: Schema<PromptConfig> = Schema.object({
-  basePrompt: Schema.computed(Schema.string().role('textarea'), options).description('默认附加的标签。').default('best quality, amazing quality, very aesthetic, absurdres'),
+  basePrompt: Schema.computed(Schema.string().role('textarea'), options)
+    .description('默认附加的标签。')
+    .default('best quality, amazing quality, very aesthetic, absurdres'),
   negativePrompt: Schema.computed(Schema.string().role('textarea'), options).description('默认附加的反向标签。').default(ucPreset),
   forbidden: Schema.computed(Schema.string().role('textarea'), options).description('违禁词列表。请求中的违禁词将会被自动删除。').default(''),
   defaultPromptSw: Schema.boolean().description('是否启用默认标签。').default(false),
@@ -199,6 +203,13 @@ export const PromptConfig: Schema<PromptConfig> = Schema.object({
   latinOnly: Schema.computed(Schema.boolean(), options).description('是否只接受英文输入。').default(false),
   lowerCase: Schema.boolean().description('是否将输入的标签转换为小写。').default(true),
   maxWords: Schema.computed(Schema.natural(), options).description('允许的最大单词数量。').default(0),
+  allowedInputImageTypes: Schema.computed(
+    Schema.array(Schema.string()).role('table').default(ALLOWED_TYPES),
+    options,
+  )
+    .description('允许从聊天平台获取的图片的文件类型，设为空列表表示忽略类型。')
+    .default(ALLOWED_TYPES),
+  transformPromptSyntax: Schema.computed(Schema.boolean(), options).description('是否自动转换输入标签的括号语法。').default(false),
 }).description('输入设置')
 
 interface FeatureConfig {
@@ -485,7 +496,7 @@ export function parseInput(session: Session, input: string, config: Config, over
     return [
       null,
       [session.resolve(config.basePrompt), session.resolve(config.defaultPrompt)].join(','),
-      session.resolve(config.negativePrompt)
+      session.resolve(config.negativePrompt),
     ]
   }
 
@@ -497,14 +508,16 @@ export function parseInput(session: Session, input: string, config: Config, over
     .replace(/《/g, '<')
     .replace(/》/g, '>')
 
-  if (config.type === 'sd-webui') {
-    input = input
-      .split('\\{').map(s => s.replace(/\{/g, '(')).join('\\{')
-      .split('\\}').map(s => s.replace(/\}/g, ')')).join('\\}')
-  } else {
-    input = input
-      .split('\\(').map(s => s.replace(/\(/g, '{')).join('\\(')
-      .split('\\)').map(s => s.replace(/\)/g, '}')).join('\\)')
+  if (session.resolve(config.transformPromptSyntax)) {
+    if (config.type === 'sd-webui') {
+      input = input
+        .split('\\{').map(s => s.replace(/\{/g, '(')).join('\\{')
+        .split('\\}').map(s => s.replace(/\}/g, ')')).join('\\}')
+    } else {
+      input = input
+        .split('\\(').map(s => s.replace(/\(/g, '{')).join('\\(')
+        .split('\\)').map(s => s.replace(/\)/g, '}')).join('\\)')
+    }
   }
 
   input = input
diff --git a/src/index.ts b/src/index.ts
index 75b8a8b..e626c8e 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -180,7 +180,7 @@ export function apply(ctx: Context, config: Config) {
         }
       } else {
         input = haveInput ? h('', h.transform(h.parse(input), {
-          image(attrs) {
+          img(attrs) {
             throw new SessionError('commands.novelai.messages.invalid-content')
           },
         })).toString(true) : input
@@ -236,7 +236,7 @@ export function apply(ctx: Context, config: Config) {
 
       if (imgUrl) {
         try {
-          image = await download(ctx, imgUrl)
+          image = await download(ctx, imgUrl, { allowedTypes: session.resolve(config.allowedInputImageTypes) })
         } catch (err) {
           if (err instanceof NetworkError) {
             return session.text(err.message, err.params)
@@ -731,7 +731,7 @@ export function apply(ctx: Context, config: Config) {
       if (!imgUrl) return session.text('.expect-image')
       let image: ImageData
       try {
-        image = await download(ctx, imgUrl)
+        image = await download(ctx, imgUrl, { allowedTypes: session.resolve(config.allowedInputImageTypes) })
       } catch (err) {
         if (err instanceof NetworkError) {
           return session.text(err.message, err.params)
diff --git a/src/utils.ts b/src/utils.ts
index 7c97433..fd2ce62 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -29,31 +29,35 @@ export function getImageSize(buffer: ArrayBuffer): Size {
   return pick(image, ['width', 'height'])
 }
 
-const MAX_OUTPUT_SIZE = 1048576
-const MAX_CONTENT_SIZE = 10485760
-const ALLOWED_TYPES = ['image/jpeg', 'image/png']
-
-export async function download(ctx: Context, url: string, headers = {}): Promise<ImageData> {
+export const MAX_OUTPUT_SIZE = 1048576
+export const MAX_CONTENT_SIZE = 10485760
+export const ALLOWED_TYPES = ['image/jpeg', 'image/png']
+
+export async function download(
+  ctx: Context,
+  url: string,
+  { headers, allowedTypes }: { headers?: Dict; allowedTypes?: string[] | null },
+): Promise<ImageData> {
+  allowedTypes = allowedTypes === undefined ? ALLOWED_TYPES : allowedTypes
+
+  let mime: string
+  let buffer: ArrayBuffer
   if (url.startsWith('data:') || url.startsWith('file:')) {
-    const { mime, data } = await ctx.http.file(url)
-    if (!ALLOWED_TYPES.includes(mime)) {
-      throw new NetworkError('.unsupported-file-type')
-    }
-    const base64 = arrayBufferToBase64(data)
-    return { buffer: data, base64, dataUrl: `data:${mime};base64,${base64}` }
+    ({ mime, data: buffer } = await ctx.http.file(url))
   } else {
     const image = await ctx.http(url, { responseType: 'arraybuffer', headers })
     if (+image.headers.get('content-length') > MAX_CONTENT_SIZE) {
       throw new NetworkError('.file-too-large')
     }
-    const mimetype = image.headers.get('content-type')
-    if (!ALLOWED_TYPES.includes(mimetype)) {
-      throw new NetworkError('.unsupported-file-type')
-    }
-    const buffer = image.data
-    const base64 = arrayBufferToBase64(buffer)
-    return { buffer, base64, dataUrl: `data:${mimetype};base64,${base64}` }
+    mime = image.headers.get('content-type')
+    buffer = image.data
+  }
+
+  if (allowedTypes && allowedTypes.length > 0 && !allowedTypes.includes(mime)) {
+    throw new NetworkError('.unsupported-file-type')
   }
+  const base64 = arrayBufferToBase64(buffer)
+  return { buffer, base64, dataUrl: `data:${mime};base64,${base64}` }
 }
 
 export async function calcAccessKey(email: string, password: string) {