diff --git a/README.md b/README.md
index cb0cfea..39e773f 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,111 @@
-# clip4clip
+# Video-Text Retrieval Embdding with CLIP4Clip
+
+*author: Chen Zhang*
+
+
+<br />
+
+
+
+## Description
+
+This operator extracts features for video or text with [CLIP4Clip](https://arxiv.org/abs/2104.08860) which can generate embeddings for text and video by jointly training a video encoder and text encoder to maximize the cosine similarity.
+
+
+<br />
+
+
+## Code Example
+
+Load an video from path './demo_video.mp4' to generate an video embedding. 
+
+Read the text 'kids feeding and playing with the horse' to generate an text embedding. 
+
+ *Write the pipeline in simplified style*:
+
+```python
+import towhee
+
+towhee.dc(['./demo_video.mp4']) \
+        .video_decode.ffmpeg(sample_type='uniform_temporal_subsample', args={'num_samples': 12}) \
+        .runas_op(func=lambda x: [y[0] for y in x]) \
+        .clip4clip(model_name='clip_vit_b32', modality='video', weight_path='./pytorch_model.bin.1') \
+        .show()
+
+towhee.dc(['kids feeding and playing with the horse']) \
+      .clip4clip(model_name='clip_vit_b32', modality='text', weight_path='./pytorch_model.bin.1') \
+      .show()
+```
+![](vect_simplified_video.png)   
+![](vect_simplified_text.png)   
+
+*Write a same pipeline with explicit inputs/outputs name specifications:*
+
+```python
+import towhee
+
+towhee.dc['path'](['./demo_video.mp4']) \
+        .video_decode.ffmpeg['path', 'frames'](sample_type='uniform_temporal_subsample', args={'num_samples': 12}) \
+        .runas_op['frames', 'frames'](func=lambda x: [y[0] for y in x]) \
+        .clip4clip['frames', 'vec'](model_name='clip_vit_b32', modality='video', weight_path='./pytorch_model.bin.1') \
+        .show()
+
+towhee.dc['text'](["kids feeding and playing with the horse"]) \
+      .clip4clip['text','vec'](model_name='clip_vit_b32', modality='text', weight_path='./pytorch_model.bin.1') \
+      .select['text', 'vec']() \
+      .show()
+```
+
+![](vect_explicit_video.png)    
+![](vect_explicit_text.png)   
+
+<br />
+
+
+
+## Factory Constructor
+
+Create the operator via the following factory method
+
+***clip4clip(model_name, modality, weight_path)***
+
+**Parameters:**
+
+​   ***model_name:*** *str*
+
+​   The model name of CLIP. Supported model names: 
+- clip_vit_b32
+
+
+​   ***modality:*** *str*
+
+​   Which modality(*video* or *text*) is used to generate the embedding. 
+
+​   ***weight_path:*** *str*
+
+​   pretrained model weights path.  
+
+<br />
+
+
+
+## Interface
+
+An video-text embedding operator takes a list of [towhee image](link/to/towhee/image/api/doc) or string as input and generate an embedding in ndarray.
+
+
+**Parameters:**
+
+​	***data:*** *List[towhee.types.Image]*  or *str*
+
+​  The data (list of image(which is uniform subsampled from a video) or text based on specified modality) to generate embedding.	
+
+
+
+**Returns:** *numpy.ndarray*
+
+​   The data embedding extracted by model.
+
+
+
 
diff --git a/clip4clip.py b/clip4clip.py
index d66af59..74a4ecd 100644
--- a/clip4clip.py
+++ b/clip4clip.py
@@ -11,31 +11,27 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-import os
-import random
-import sys
-from pathlib import Path
 
 import numpy as np
 import torch
 import towhee
+
+from typing import List, Union
 from torchvision import transforms
 from towhee.models.clip4clip import convert_tokens_to_id
-
-from towhee.types.image_utils import to_pil
-from towhee.operator.base import NNOperator, OperatorFlag
-from towhee.types.arg import arg, to_image_color
+from towhee.operator.base import NNOperator
 from towhee import register
 from towhee.models import clip4clip
-from towhee.utils.ndarray_utils import to_ndarray
 from PIL import Image as PILImage
+from towhee.types.image import Image
 
 
-@register(name='clip4clip', output_schema=['vec'])
+@register(output_schema=['vec'])
 class CLIP4Clip(NNOperator):
     """
-    CLIP multi-modal embedding operator
+    CLIP4Clip multi-modal embedding operator
     """
+
     def __init__(self, model_name: str, modality: str, weight_path: str = None):
         super().__init__()
         self.modality = modality
@@ -52,11 +48,11 @@ class CLIP4Clip(NNOperator):
             transforms.CenterCrop(224),
             transforms.ToTensor(),
             transforms.Normalize(
-               (0.48145466, 0.4578275, 0.40821073), (0.26862954, 0.26130258, 0.27577711))
-            ])
+                (0.48145466, 0.4578275, 0.40821073), (0.26862954, 0.26130258, 0.27577711))
+        ])
         self.model.eval()
 
-    def __call__(self, data):
+    def __call__(self, data: Union[str, List[Image]]):
         if self.modality == 'video':
             vec = self._inference_from_video(data)
         elif self.modality == 'text':
@@ -64,43 +60,33 @@ class CLIP4Clip(NNOperator):
         else:
             raise ValueError("modality[{}] not implemented.".format(self._modality))
         return vec
-    #
-    def _inference_from_text(self, text):
+
+    def _inference_from_text(self, text: str):
         self.model.eval()
-        # text = self.tokenize(text)
         text_ids = convert_tokens_to_id(self.tokenize, text)
-        print(text_ids)
         text_ids = torch.tensor(text_ids).unsqueeze(0).to(self.device)
         text_features = self.model.get_sequence_output(text_ids)
         text_features = text_features / text_features.norm(dim=-1, keepdim=True)
-        # print(text_features.norm(dim=-1, keepdim=True))
-        return text_features#.unsqueeze(0).cpu().numpy()
+        return text_features.detach().flatten().cpu().numpy()
 
-    def _inference_from_video(self, img_list):
+    def _inference_from_video(self, img_list: List[Image]):
         self.model.eval()
-        # video = self.tfms(video)
         max_frames = 12
-        video = np.zeros((1, max_frames, 1, 3, 224, 224), dtype=np.float)
+        video = np.zeros((1, max_frames, 1, 3, 224, 224), dtype=np.float64)
         slice_len = len(img_list)
         max_video_length = 0 if 0 > slice_len else slice_len
         for i, img in enumerate(img_list):
             pil_img = PILImage.fromarray(img.to_ndarray(), img.mode)
             tfmed_img = self.tfms(pil_img).unsqueeze(0).to(self.device)
-            print('tfmed_img.shape', tfmed_img.shape)
-
             if slice_len >= 1:
                 video[0, i, ...] = tfmed_img
-        video_mask = np.zeros((1, max_frames), dtype=np.long)
+        video_mask = np.zeros((1, max_frames), dtype=np.int32)
         video_mask[0, :max_video_length] = [1] * max_video_length
 
         video = torch.as_tensor(video).float()
         pair, bs, ts, channel, h, w = video.shape
         video = video.view(pair * bs * ts, channel, h, w)
         video_mask = torch.as_tensor(video_mask).float()
-        #     video_list.append(video)
-        #     video_mask_list.append(video_mask)
-        # video_list_tensor = torch.cat(video_list, dim=0)
-        # video_mask_list_tensor = torch.cat(video_mask_list, dim=0)
 
         visual_output = self.model.get_visual_output(video, video_mask, shaped=True)
 
@@ -114,44 +100,4 @@ class CLIP4Clip(NNOperator):
 
         visual_output = visual_output / visual_output.norm(dim=-1, keepdim=True)
 
-        return visual_output#.unsqueeze(0).cpu().numpy()
-
-
-    #
-    # @arg(1, to_image_color('RGB'))
-    # def _inference_from_video(self, img):
-    #     img = to_pil(img)
-    #     image = self.tfms(img).unsqueeze(0).to(self.device)
-    #     image_features = self.model.encode_image(image)
-    #     return image_features
-if __name__ == '__main__':
-    # op = CLIP4Clip('clip_vit_b32', 'text', './pytorch_model.bin.1')
-    # res = op('kids feeding and playing with the horse')
-    # print(res.shape)
-
-
-
-
-    # from towhee import ops
-    # op = CLIP4Clip('clip_vit_b32', 'video', './pytorch_model.bin.1')
-    # d = ops.video_decode.ffmpeg(sample_type='uniform_temporal_subsample',
-    #                             args={'num_samples': 12})
-    # # ops.video_decode.get_video_duration()
-    video_path = '/Users/zilliz/dataset/MSRVTT/MSRVTT/videos/all/video9451.mp4'
-    # img_list = []
-    # for frame in d(video_path):
-    #     print(frame)
-    #     img_list.append(frame[0])
-    # res = op(img_list)
-    # print(res.shape)
-
-    dc = (
-        towhee.dc['path']([video_path])
-            .video_decode.ffmpeg['path', 'frames'](
-                sample_type='uniform_temporal_subsample',
-                args={'num_samples': 12})
-            .runas_op['frames', 'frames'](func=lambda x: [y[0] for y in x])
-            .clip4clip['frames', 'vec'](model_name='clip_vit_b32', modality='video', weight_path='./pytorch_model.bin.1')
-    )
-    dc.show()
-
+        return visual_output.detach().flatten().cpu().numpy()
diff --git a/demo_video.mp4 b/demo_video.mp4
new file mode 100755
index 0000000..e6fb645
Binary files /dev/null and b/demo_video.mp4 differ
diff --git a/vect_explicit_text.png b/vect_explicit_text.png
new file mode 100644
index 0000000..9569f6f
Binary files /dev/null and b/vect_explicit_text.png differ
diff --git a/vect_explicit_video.png b/vect_explicit_video.png
new file mode 100644
index 0000000..c534085
Binary files /dev/null and b/vect_explicit_video.png differ
diff --git a/vect_simplified_text.png b/vect_simplified_text.png
new file mode 100644
index 0000000..7ce111d
Binary files /dev/null and b/vect_simplified_text.png differ
diff --git a/vect_simplified_video.png b/vect_simplified_video.png
new file mode 100644
index 0000000..a4a3235
Binary files /dev/null and b/vect_simplified_video.png differ