update the readme.

Signed-off-by: wxywb <xy.wang@zilliz.com>

README.md

@@ -19,28 +19,20 @@ This operator generates the caption with [ClipCap](https://arxiv.org/abs/2111.09
 
 Load an image from path './hulk.jpg' to generate the caption. 
 
- *Write the pipeline in simplified style*:
+*Write a pipeline with explicit inputs/outputs name specifications:*
 
 ```python
-import towhee
+from towhee.dc2 import pipe, ops, DataCollection
 
-towhee.glob('./hulk.jpg') \
-      .image_decode() \
-      .image_captioning.clipcap(model_name='clipcap_coco') \
-      .show()
-```
-<img src="./cap.png" alt="result1" style="height:20px;"/>
-
-*Write a same pipeline with explicit inputs/outputs name specifications:*
+p = (
+    pipe.input('url')
+    .map('url', 'img', ops.image_decode.cv2_rgb())
+    .map('img', 'text', ops.image_captioning.clipcap(model_name='clipcap_coco'))
+    .output('img', 'text')
+)
 
-```python
-import towhee
+DataCollection(p('./image.jpg')).show()
 
-towhee.glob['path']('./hulk.jpg') \
-      .image_decode['path', 'img']() \
-      .image_captioning.clipcap['img', 'text'](model_name='clipcap_coco') \
-      .select['img', 'text']() \
-      .show()
 ```
 <img src="./tabular.png" alt="result2" style="height:60px;"/>
 

clipcap.py

@@ -55,9 +55,9 @@ class ClipCap(NNOperator):
         self.model = ClipCaptionModel(self.prefix_length)
         model_path = os.path.dirname(__file__) + '/weights/' + config['weights']
         self.model.load_state_dict(torch.load(model_path, map_location=torch.device('cpu')))
+        self.model.to(self.device)
         self.model = self.model.eval()
         
-        
     @arg(1, to_image_color('RGB'))
     def inference_single_data(self, data):
         text = self._inference_from_image(data)
@@ -85,7 +85,7 @@ class ClipCap(NNOperator):
     @arg(1, to_image_color('RGB'))
     def _inference_from_image(self, img):
         img = self._preprocess(img)
-        clip_feat = self.clip_model.encode_image(img)
+        clip_feat = self.clip_model.encode_image(img).float()
 
         self.prefix_length = 10
         prefix_embed = self.model.clip_project(clip_feat).reshape(1, self.prefix_length, -1)