diff --git a/README.md b/README.md
index 0fba965..7f4430f 100644
--- a/README.md
+++ b/README.md
@@ -10,7 +10,7 @@
 
 ## Description
 
-An image decode operator implementation with OpenCV. Return BGR image.
+An image decode operator implementation with OpenCV. 
 
 
 
@@ -32,22 +32,31 @@ the src picture:
 from towhee.dc2 import pipe, ops, DataCollection
 
 
+# decode image, in bgr channel order
 p = (
   pipe.input('url')
   .map('url', 'image', ops.image_decode.cv2())
   .output('image')
 )
 
+# decode image, in rgb channel order
+p2 = (
+  pipe.input('url')
+  .map('url', 'image', ops.image_decode.cv2('rgb'))
+  .output('image')
+)
+
 # decode from path
 DataCollection(p('./src_dog.jpg')).show()
 
 # decode from bytes
 with open('./src_dog.jpg', 'rb') as f:
-  DataCollection(p(f.read())).show()
+  DataCollection(p2(f.read())).show()
 ```
 
 <br />
 <img src="./dog.png" height="150px"/>
+<img src="./src_dog.jpg" height="150px"/>
 
 
 
@@ -59,8 +68,11 @@ with open('./src_dog.jpg', 'rb') as f:
 
 Create the operator via the following factory method:
 
-***image_decode.cv2()***
+***ops.image_decode.cv2()***
+
+**mode**: *str*
 
+BGR or RGB, default is BGR
 
 
 <br />
@@ -69,7 +81,7 @@ Create the operator via the following factory method:
 
 ## Interface
 
-An image decode operator takes an image path as input. It decodes the image back to ndarray, use BGR channel order.
+An image decode operator takes an image path as input. It decodes the image back to ndarray.
 
 
 
@@ -77,7 +89,7 @@ An image decode operator takes an image path as input. It decodes the image back
 
 **img**: *str*
 
-​	Local file path or http url.
+​	Local file path/http url/image bytes.