transformers/docs/source/en/model_doc/vision-text-dual-encoder.mdx

<!--Copyright 2021 The HuggingFace Team. All rights reserved.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
an "AS IS" BASIS, 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.
-->

# VisionTextDualEncoder

## Overview

The [`VisionTextDualEncoderModel`] can be used to initialize a vision-text dual encoder model with
any pretrained vision autoencoding model as the vision encoder (*e.g.* [ViT](vit), [BEiT](beit), [DeiT](deit)) and any pretrained text autoencoding model as the text encoder (*e.g.* [RoBERTa](roberta), [BERT](bert)). Two projection layers are added on top of both the vision and text encoder to project the output embeddings
to a shared latent space. The projection layers are randomly initialized so the model should be fine-tuned on a
downstream task. This model can be used to align the vision-text embeddings using CLIP like contrastive image-text
training and then can be used for zero-shot vision tasks such image-classification or retrieval.

In [LiT: Zero-Shot Transfer with Locked-image Text Tuning](https://arxiv.org/abs/2111.07991) it is shown how
leveraging pre-trained (locked/frozen) image and text model for contrastive learning yields significant improvement on
new zero-shot vision tasks such as image classification or retrieval.

## VisionTextDualEncoderConfig

[[autodoc]] VisionTextDualEncoderConfig

## VisionTextDualEncoderProcessor

[[autodoc]] VisionTextDualEncoderProcessor

## VisionTextDualEncoderModel

[[autodoc]] VisionTextDualEncoderModel
    - forward

## FlaxVisionTextDualEncoderModel

[[autodoc]] FlaxVisionTextDualEncoderModel
    - __call__

## TFVisionTextDualEncoderModel

[[autodoc]] TFVisionTextDualEncoderModel
    - call