diff --git a/README.md b/README.md
index 0fe3fc4..397c94c 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 [![NPM version](https://img.shields.io/npm/v/qrcode-parser.svg?style=flat)](https://npmjs.com/package/qrcode-parser) [![NPM downloads](https://img.shields.io/npm/dm/qrcode-parser.svg?style=flat)](https://npmjs.com/package/qrcode-parser) [![CircleCI](https://circleci.com/gh/sinchang/qrcode-parser/tree/master.svg?style=shield)](https://circleci.com/gh/sinchang/qrcode-parser/tree/master)
 
-A pure javascript QR code reading library, accept File object, image url, image base64.
+A pure javascript QR code decoding library, accept PNG File object, PNG image url, image base64.
 
 ## Example
 
@@ -19,7 +19,7 @@ yarn add qrcode-parser
 ```js
 import qrcodeParser from "qrcode-parser";
 
-// input should be File object, image url, image base64
+// input should be PNG File object, PNG image url, image base64
 qrcodeParser(input);
 // => return promise
 ```
diff --git a/package.json b/package.json
index cc0ba78..41a304f 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "qrcode-parser",
   "version": "2.0.0",
-  "description": "A pure javascript QR code reading library, accept File object, image url, image base64.",
+  "description": "A pure javascript QR code decoding library, accept PNG File object, PNG image url, image base64.",
   "repository": {
     "url": "sinchang/qrcode-parser",
     "type": "git"