# Image-Text Retrieval Embdding with CLIP
*author: David Wang*
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## Description
This operator extracts features for image or text with [CLIP ](https://arxiv.org/abs/2103.00020 ) which can generate embeddings for text and image by jointly training an image encoder and text encoder to maximize the cosine similarity.
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## Code Example
Load an image from path './teddy.jpg' to generate an image embedding.
Read the text 'A teddybear on a skateboard in Times Square.' to generate an text embedding.
*Write a pipeline with explicit inputs/outputs name specifications:*
```python
from towhee.dc2 import pipe, ops, DataCollection
img_pipe = (
pipe.input('url')
.map('url', 'img', ops.image_decode.cv2_rgb())
.map('img', 'vec', ops.image_text_embedding.clip(model_name='clip_vit_base_patch16', modality='image'))
.output('img', 'vec')
)
text_pipe = (
pipe.input('text')
.map('text', 'vec', ops.image_text_embedding.clip(model_name='clip_vit_base_patch16', modality='text'))
.output('text', 'vec')
)
DataCollection(img_pipe('./teddy.jpg')).show()
DataCollection(text_pipe('A teddybear on a skateboard in Times Square.')).show()
```
< img src = "https://towhee.io/image-text-embedding/clip/raw/branch/main/tabular1.png" alt = "result1" style = "height:60px;" / >
< img src = "https://towhee.io/image-text-embedding/clip/raw/branch/main/tabular2.png" alt = "result2" style = "height:60px;" / >
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## Factory Constructor
Create the operator via the following factory method
***clip(model_name, modality)***
**Parameters:**
** *model_name:*** *str*
The model name of CLIP. Supported model names:
- clip_vit_base_patch16
- clip_vit_base_patch32
- clip_vit_large_patch14
- clip_vit_large_patch14_336
** *modality:*** *str*
Which modality(*image* or *text* ) is used to generate the embedding.
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***checkpoint_path***: *str*
The path to local checkpoint, defaults to None.
If None, the operator will download and load pretrained model by `model_name` from Huggingface transformers.
## Interface
An image-text embedding operator takes a [towhee image ](link/to/towhee/image/api/doc ) or string as input and generate an embedding in ndarray.
***save_model(format='pytorch', path='default')***
Save model to local with specified format.
**Parameters:**
***format***: *str*
The format of saved model, defaults to 'pytorch'.
***path***: *str*
The path where model is saved to. By default, it will save model to the operator directory.
```python
from towhee import ops
op = ops.image_text_embedding.clip(model_name='clip_vit_base_patch16', modality='image').get_op()
op.save_model('onnx', 'test.onnx')
```
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**Parameters:**
** *data:*** *towhee.types.Image (a sub-class of numpy.ndarray)* or *str*
The data (image or text based on specified modality) to generate embedding.
**Returns:** *numpy.ndarray*
The data embedding extracted by model.
***supported_model_names(format=None)***
Get a list of all supported model names or supported model names for specified model format.
**Parameters:**
***format***: *str*
The model format such as 'pytorch', 'torchscript'.
```python
from towhee import ops
op = towhee.ops.image_text_embedding.clip(model_name='clip_vit_base_patch16', modality='image').get_op()
full_list = op.supported_model_names()
onnx_list = op.supported_model_names(format='onnx')
print(f'Onnx-support/Total Models: {len(onnx_list)}/{len(full_list)}')
```
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## Fine-tune
### Requirement
If you want to train this operator, besides dependency in requirements.txt, you need install these dependencies.
```python
! python -m pip install datasets evaluate
```
### Get start
```python
import towhee
clip_op = towhee.ops.image_text_embedding.clip(model_name='clip_vit_base_patch16', modality='image').get_op()
data_args = {
'dataset_name': 'ydshieh/coco_dataset_script',
'dataset_config_name': '2017',
'cache_dir': './cache',
'max_seq_length': 77,
'data_dir': path_to_your_coco_dataset,
'image_mean': [0.48145466, 0.4578275, 0.40821073],
"image_std": [0.26862954, 0.26130258, 0.27577711]
}
training_args = {
'num_train_epochs': 3, # you can add epoch number to get a better metric.
'per_device_train_batch_size': 8,
'per_device_eval_batch_size': 8,
'do_train': True,
'do_eval': True,
'remove_unused_columns': False,
'output_dir': './tmp/test-clip',
'overwrite_output_dir': True,
}
clip_op.train(data_args=data_args, training_args=training_args)
```
### Dive deep and customize your training
You can change the [training script ](https://towhee.io/image-text-embedding/clip/src/branch/main/train_clip_with_hf_trainer.py ) in your customer way.
Or your can refer to the original [hugging face transformers training examples ](https://github.com/huggingface/transformers/tree/main/examples/pytorch/contrastive-image-text ).
