opensearch-docs-cn/_api-reference/ingest-apis/processors/text-image-embedding.md

layout	title	parent	grand_parent	nav_order
default	Text/image embedding	Ingest processors	Ingest APIs	270

Text/image embedding

The text_image_embedding processor is used to generate combined vector embeddings from text and image fields for multimodal neural search.

PREREQUISITE
Before using the text_image_embedding processor, you must set up a machine learning (ML) model. For more information, see Using custom models within OpenSearch and Semantic search. {: .note}

The following is the syntax for the text_image_embedding processor:

{
  "text_image_embedding": {
    "model_id": "<model_id>",
    "embedding": "<vector_field>",
    "field_map": {
      "text": "<input_text_field>",
      "image": "<input_image_field>"
    }
  }
}

{% include copy-curl.html %}

Parameters

The following table lists the required and optional parameters for the text_image_embedding processor.

Name	Data type	Required	Description
model_id	String	Required	The ID of the model that will be used to generate the embeddings. The model must be deployed in OpenSearch before it can be used in neural search. For more information, see Using custom models within OpenSearch and Semantic search.
embedding	String	Required	The name of the vector field in which to store the generated embeddings. A single embedding is generated for both text and image fields.
field_map	Object	Required	Contains key-value pairs that specify the fields from which to generate embeddings.
field_map.text	String	Optional	The name of the field from which to obtain text for generating vector embeddings. You must specify at least one text or image.
field_map.image	String	Optional	The name of the field from which to obtain the image for generating vector embeddings. You must specify at least one text or image.
description	String	Optional	A brief description of the processor.
tag	String	Optional	An identifier tag for the processor. Useful for debugging to distinguish between processors of the same type.

Using the processor

Follow these steps to use the processor in a pipeline. You must provide a model ID when creating the processor. For more information, see Using custom models within OpenSearch.

Step 1: Create a pipeline.

The following example request creates an ingest pipeline where the text from image_description and the image from image_binary will be converted into vector embeddings and the embeddings will be stored in vector_embedding:

PUT /_ingest/pipeline/nlp-ingest-pipeline
{
  "description": "A text/image embedding pipeline",
  "processors": [
    {
      "text_image_embedding": {
        "model_id": "bQ1J8ooBpBj3wT4HVUsb",
        "embedding": "vector_embedding",
        "field_map": {
          "text": "image_description",
          "image": "image_binary"
        }
      }
    }
  ]
}

{% include copy-curl.html %}

You can set up multiple processors in one pipeline to generate embeddings for multiple fields. {: .note}

Step 2 (Optional): Test the pipeline.

It is recommended that you test your pipeline before you ingest documents. {: .tip}

To test the pipeline, run the following query:

POST _ingest/pipeline/nlp-ingest-pipeline/_simulate
{
  "docs": [
    {
      "_index": "testindex1",
      "_id": "1",
      "_source":{
         "image_description": "Orange table",
         "image_binary": "bGlkaHQtd29rfx43..."
      }
    }
  ]
}

{% include copy-curl.html %}

Response

The response confirms that in addition to the image_description and image_binary fields, the processor has generated vector embeddings in the vector_embedding field:

{
  "docs": [
    {
      "doc": {
        "_index": "testindex1",
        "_id": "1",
        "_source": {
          "vector_embedding": [
            -0.048237972,
            -0.07612712,
            0.3262124,
            ...
            -0.16352308
          ],
          "image_description": "Orange table",
          "image_binary": "bGlkaHQtd29rfx43..."
        },
        "_ingest": {
          "timestamp": "2023-10-05T15:15:19.691345393Z"
        }
      }
    }
  ]
}

Next steps

• To learn how to use the neural query for a multimodal search, see Neural query.
• To learn more about multimodal neural search, see Multimodal search.
• To learn more about using models in OpenSearch, see Using custom models within OpenSearch.
• For a semantic search tutorial, see Semantic search.