ImageFileToImageContent

ImageFileToImageContent reads local image files and converts them into ImageContent objects. These are ready for multimodal AI pipelines, including tasks like image captioning, visual QA, or prompt-based generation.


Most common position in a pipeline	Before a `ChatPromptBuilder` in a query pipeline
Mandatory run variables	"sources": A list of image file paths or ByteStreams
Output variables	"image_contents": A list of ImageContent objects
API reference	Image Converters
GitHub link	https://github.com/deepset-ai/haystack/blob/main/haystack/components/converters/image/file_to_image.py

Overview

ImageFileToImageContent processes a list of image sources and converts them into ImageContent objects. These can be used in multimodal pipelines that require base64-encoded image input.

Each source can be:

A file path (string or Path), or
A ByteStream object.

Optionally, you can provide metadata using the meta parameter. This can be a single dictionary (applied to all images) or a list matching the length of sources.

Use the size parameter to resize images while preserving aspect ratio. This reduces memory usage and transmission size, which is helpful when working with remote models or limited-resource environments.

This component is often used in query pipelines just before a ChatPromptBuilder.

Usage

On its own


from haystack.components.converters.image import ImageFileToImageContent

converter = ImageFileToImageContent(detail="high", size=(800, 600))

sources = ["cat.jpg", "scenery.png"]

result = converter.run(sources=sources)
image_contents = result["image_contents"]
print(image_contents)

# [
#     ImageContent(
#         base64_image="/9j/4A...", mime_type="image/jpeg", detail="high",
#         meta={"file_path": "cat.jpg"}
#     ),
#     ImageContent(
#         base64_image="/9j/4A...", mime_type="image/png", detail="high",
#         meta={"file_path": "scenery.png"}
#     )
# ]

In a pipeline

Use ImageFileToImageContent to supply image data to a ChatPromptBuilder for multimodal QA or captioning with an LLM.

from haystack import Pipeline
from haystack.components.builders import ChatPromptBuilder
from haystack.components.generators.chat import OpenAIChatGenerator
from haystack.components.converters.image import ImageFileToImageContent

# Query pipeline
pipeline = Pipeline()
pipeline.add_component("image_converter", ImageFileToImageContent(detail="auto"))
pipeline.add_component(
    "chat_prompt_builder",
    ChatPromptBuilder(
        required_variables=["question"],
        template="""{% message role="system" %}
You are a helpful assistant that answers questions using the provided images.
{% endmessage %}

{% message role="user" %}
Question: {{ question }}

{% for img in image_contents %}
{{ img | templatize_part }}
{% endfor %}
{% endmessage %}
"""
    )
)
pipeline.add_component("llm", OpenAIChatGenerator(model="gpt-4o-mini"))

pipeline.connect("image_converter", "chat_prompt_builder.image_contents")
pipeline.connect("chat_prompt_builder", "llm")

sources = ["apple.jpg", "haystack-logo.png"]

result = pipeline.run(
    data={
        "image_converter": {"sources": sources},
        "chat_prompt_builder": {"question": "Describe the Haystack logo."}
    }
)
print(result)

# {
# "llm": {
#     "replies": [
#         ChatMessage(
#             _role=<ChatRole.ASSISTANT: 'assistant'>,
#             _content=[TextContent(text="The Haystack logo features...")],
#             ...
#         )
#     ]
# }
# }

Additional References

🧑‍🍳 Cookbook: Introduction to Multimodality

Updated 1 day ago