update the image for expansionnet_v2.

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

README.md

@@ -1,2 +1,78 @@
-# expansionnet-v2
+# Image Captioning with ExpansionNet v2
 
+*author: David Wang*
+
+
+<br />
+
+
+## Description
+
+This operator generates the caption with [ExpansionNet v2](https://arxiv.org/abs/2208.06551) which describes the content of the given image. ExpansionNet v2 introduces the Block Static Expansion which distributes and processes the input over a heterogeneous and arbitrarily big collection of sequences characterized by a different length compared to the input one. This is an adaptation from [jchenghu/ExpansionNet_v2](https://github.com/jchenghu/expansionnet_v2).
+
+
+<br />
+
+
+## Code Example
+
+Load an image from path './image.jpg' to generate the caption. 
+
+ *Write the pipeline in simplified style*:
+
+```python
+import towhee
+
+towhee.glob('./image.jpg') \
+      .image_decode() \
+      .image_captioning.expansionnet_v2(model_name='expansionnet_rf') \
+      .show()
+```
+<img src="./cap.png" alt="result1" style="height:20px;"/>
+
+*Write a same pipeline with explicit inputs/outputs name specifications:*
+
+```python
+import towhee
+
+towhee.glob['path']('./image.jpg') \
+      .image_decode['path', 'img']() \
+      .image_captioning.expansionnet_v2['img', 'text'](model_name='expansionnet_rf') \
+      .select['img', 'text']() \
+      .show()
+```
+<img src="./tabular.png" alt="result2" style="height:60px;"/>
+
+
+<br />
+
+
+## Factory Constructor
+
+Create the operator via the following factory method
+
+***expansionnet_v2(model_name)***
+
+**Parameters:**
+
+​   ***model_name:*** *str*
+
+​   The model name of ExpansionNet v2. Supported model names: 
+- expansionnet_rf    
+
+<br />
+
+## Interface
+
+An image captioning operator takes a [towhee image](link/to/towhee/image/api/doc) as input and generate the correspoing caption.
+
+
+**Parameters:**
+
+​	***data:*** *towhee.types.Image (a sub-class of numpy.ndarray)* 
+
+​  The image to generate caption.
+
+**Returns:** *str*
+
+​   The caption generated by model.

expansionnet_v2.py

@@ -82,7 +82,8 @@ class ExpansionNetV2(NNOperator):
                                     max_seq_len=max_seq_len, drop_args=model_args.drop_args,
                                 rank='cpu')
 
-        checkpoint = torch.load('{}/weights/rf_model.pth'.format(path), map_location=torch.device('cpu'))
+        cfg = self.model._configs()[model_name]
+        checkpoint = torch.load('{}/weights/{}'.format(cfg,cfg['weights']), map_location=torch.device('cpu'))
         self.model.load_state_dict(checkpoint['model_state_dict'])
         self.model.to(self.device)
 
@@ -132,3 +133,9 @@ class ExpansionNetV2(NNOperator):
         pred = ' '.join(pred).capitalize()
 
         return pred
+
+    def _configs(self):
+        config = {}
+        config['expansionnet_rf'] = {}
+        config['expansionnet_rf']['weights'] = 'rf_model.pth'
+        return config