update the doc.

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

README.md

@@ -18,28 +18,19 @@ This operator generates the caption with [CapDec](https://arxiv.org/abs/2211.005
 
 Load an image from path './image.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('./image.jpg') \
-      .image_decode() \
-      .image_captioning.capdec(model_name='capdec_noise_0') \
-      .show()
-```
-<img src="./cap.png" alt="result1" style="height:20px;"/>
-
-*Write a same pipeline with explicit inputs/outputs name specifications:*
-
-```python
-import towhee
+p = (
+    pipe.input('url')
+    .map('url', 'img', ops.image_decode.cv2_rgb())
+    .map('img', 'text', ops.image_captioning.capdec(model_name='capdec_noise_0')
+    .output('img', 'text')
+)
 
-towhee.glob['path']('./image.jpg') \
-      .image_decode['path', 'img']() \
-      .image_captioning.capdec['img', 'text'](model_name='capdec_noise_0') \
-      .select['img', 'text']() \
-      .show()
+DataCollection(p('./image.jpg')).show()
 ```
 <img src="./tabular.png" alt="result2" style="height:60px;"/>
 

capdec.py

@@ -55,7 +55,7 @@ class Capdec(NNOperator):
         self.clip_model = clip.create_model(model_name='clip_resnet_r50x4', pretrained=True, jit=True)
         self.clip_model.to(self.device)
         self.clip_tfms = clip.get_transforms(model_name='clip_resnet_r50x4')  
-        self.tokenizer = GPT2Tokenizer.from_pretrained("gpt2").to(self.device)
+        self.tokenizer = GPT2Tokenizer.from_pretrained("gpt2")
         self.generate_beam = generate_beam
         self.generate2 = generate2