Add support for multimodal embeddings in vectorizers

[vishal-bala]

This PR generalizes the BaseVectorizer to be agnostic to any modality (since it previously exclusively supported text inputs). Building from the new base, this PR then extends the implementation for some vectorizers to support multimodal embeddings (renaming them away from being specifically for text).

BaseVectorizer

The move away from having the BaseVectorizer explicitly expect text inputs means a change in the signature of the embed methods away from vectorizer.embed(text="lorem ipsum...") to vectorizer.embed(content="lorem ipsum..."). This is a breaking change for existing usages of the vectorizers that use the keyword argument, and the usages will need to be updated to align with the new schema.

Caching for multimodal embeddings is supported for all vectorizers introduced in this PR.

Multimodal Implementations

The following vectorizers have been renamed to no longer be explicitly text vectorizers, and moved to no longer be defined in the vectorize.text module. Imports and usages for these vectorizers will need to be updated to avoid errors. The CustomTextVectorizer has also been renamed and moved to be redisvl.utils.vectorize.custom.CustomVectorizer.

VoyageAI

Old: redisvl.utils.vectorize.text.voyageai.VoyageAITextVectorizer
New: redisvl.utils.vectorize.voyageai.VoyageAIVectorizer

from redisvl.utils.vectorize import VoyageAIVectorizer

# --- Basic usage
vectorizer = VoyageAIVectorizer(
    model="voyage-3-large",
    api_config={"api_key": "your-voyageai-api-key"} # OR set VOYAGE_API_KEY in your env
)
query_embedding = vectorizer.embed(
    content="your input query text here",
    input_type="query"
)
doc_embeddings = vectorizer.embed_many(
    contents=["your document text", "more document text"],
    input_type="document"
)

# --- Multimodal usage - requires Pillow and voyageai>=0.3.6 (for video)
from PIL import Image
from voyageai.video_utils import Video

vectorizer = VoyageAIVectorizer(
    model="voyage-multimodal-3.5",
    api_config={"api_key": "your-voyageai-api-key"} # OR set VOYAGE_API_KEY in your env
)

# text
text_embedding = vectorizer.embed(
    content="your input query text here",
    input_type="query"
)

# image
image_embedding = vectorizer.embed_image(
    "path/to/your/image.jpg",
    input_type="query"
)
image_embedding = vectorizer.embed(
    Image.open("path/to/your/image.jpg"),
    input_type="query"

# video
video_embedding = vectorizer.embed_video(
    "path/to/your/video.mp4",
    input_type="document"
)
video_embedding = vectorizer.embed(
    Video.from_path("path/to/your/video.mp4", model=vectorizer.model),
    input_type="document"
)

Vertex AI

Old: redisvl.utils.vectorize.text.vertexai.VertexAITextVectorizer
New: redisvl.utils.vectorize.vertexai.VertexAIVectorizer

from redisvl.utils.vectorize import VertexAIVectorizer

# Basic usage

vectorizer = VertexAIVectorizer(
    model="textembedding-gecko",
    api_config={
        "project_id": "your_gcp_project_id", # OR set GCP_PROJECT_ID
        "location": "your_gcp_location",     # OR set GCP_LOCATION
    })
embedding = vectorizer.embed("Hello, world!")

# Multimodal usage
from vertexai.vision_models import Image, Video

vectorizer = VertexAIVectorizer(
    model="multimodalembedding@001",
    api_config={
        "project_id": "your_gcp_project_id", # OR set GCP_PROJECT_ID
        "location": "your_gcp_location",     # OR set GCP_LOCATION
    }
)
text_embedding = vectorizer.embed("Hello, world!")

image_embedding = vectorizer.embed(Image.load_from_file("path/to/your/image.jpg"))
image_embedding = vectorizer.embed_image("path/to/your/image.jpg")

video_embedding = vectorizer.embed(Video.load_from_file("path/to/your/video.mp4"))
video_embedding = vectorizer.embed_video("path/to/your/video.mp4")

Amazon Bedrock

Old: redisvl.utils.vectorize.text.bedrock.BedrockTextVectorizer
New: redisvl.utils.vectorize.bedrock.BedrockVectorizer

from redisvl.utils.vectorize import BedrockVectorizer

vectorizer = BedrockVectorizer(
    model="amazon.titan-embed-text-v2:0",
    api_config={
        "aws_access_key_id": "your_access_key",
        "aws_secret_access_key": "your_secret_key",
        "aws_region": "us-east-1"
    }
)

embedding = vectorizer.embed("Hello, world!")

# Multimodal usage
from pathlib import Path
from PIL import Image

vectorizer = BedrockVectorizer(
    model="amazon.titan-embed-image-v1:0",
    api_config={
        "aws_access_key_id": "your_access_key",
        "aws_secret_access_key": "your_secret_key",
        "aws_region": "us-east-1"
    }
)
image_embedding = vectorizer.embed(Path("path/to/your/image.jpg"))
image_embedding = vectorizer.embed(Image.open("path/to/other/image.png"))
image_embedding = vectorizer.embed_image("path/to/your/image.jpg")

# Embedding a list of mixed modalities
embeddings = vectorizer.embed_many(
    ["Hello", "world!", Path("path/to/your/image.jpg"), Image.open("path/to/other/image.png")],
    batch_size=2
)

Hugging Face

While the sentence-transformers package does not explicitly allow for multimodal usage (the package is designed for text-based use-cases), some officially supported multimodal models can be used without issue via the SentenceTransformer class. This PR removes strict enforcement of text inputs for the HFTextVectorizer to enable these use-cases.

from PIL import Image
from redisvl.utils.vectorize import HFTextVectorizer

vectorizer = HFTextVectorizer(model="sentence-transformers/clip-ViT-L-14")
embeddings1 = vectorizer.embed("Hello, world!")
embeddings2 = vectorizer.embed(Image.open("path/to/your/image.jpg"))

Open Topics

Since this PR introduces a few breaking changes, do we want to maintain backwards compatibility (with deprecation warnings) for syntax that is changing? This includes:

• vectorizer.embed(text=...) -> vectorizer.embed(content=...)
• VoyageAITextVectorizer -> VoyageAIVectorizer
• VertexAITextVectorizer -> VertexAIVectorizer
• BedrockTextVectorizer -> BedrockVectorizer
• CustomTextVectorizer -> CustomVectorizer

[justin-cechmanek]

All the changes look good. Not sure how to best handle the breaking changes around the vectorizer class names and text/content parameter name.

[justin-cechmanek]

We can maintain backward compatibility and a deprecation warning by having wrapper classes that extend the newly changed vectorizers.

[vishal-bala]

I've implemented backwards compatibility as follows:

>>> # Wrapper imports for VoyageAITextVectorizer, BedrockTextVectorizer, CustomTextVectorizer, VertexAITextVectorizer
>>> # Warning if the multimodal vectorizers are used via their text aliases
>>> from redisvl.utils.vectorize import VoyageAITextVectorizer
>>> vec = VoyageAITextVectorizer(api_config={"api_key": "<YOUR API KEY>"})
DeprecationWarning: Class VoyageAITextVectorizer is deprecated and will be removed in the next major release. Use VoyageAIVectorizer instead.
  vec = VoyageAITextVectorizer(api_config={"api_key": "<YOUR API KEY>"})

>>> # Warning if the `text` argument is explicitly used for any of the existing vectorizers
>>> emb = vec.embed("example")
>>> emb = vec.embed(content="example")
>>> emb = vec.embed(text="example")
DeprecationWarning: Argument text is deprecated and will be removed in the next major release. Use content instead.
  emb = vec.embed(text="example")

[justin-cechmanek]

LGTM!