import base64 import io import os import uuid from io import BytesIO from pathlib import Path from langchain.chat_models import ChatOllama from langchain.embeddings import OllamaEmbeddings from langchain.retrievers.multi_vector import MultiVectorRetriever from langchain.schema.document import Document from langchain.schema.messages import HumanMessage from langchain.storage import LocalFileStore from langchain.vectorstores import Chroma from PIL import Image def image_summarize(img_base64, prompt): """ Make image summary :param img_base64: Base64 encoded string for image :param prompt: Text prompt for summarizatiomn :return: Image summarization prompt """ chat = ChatOllama(model="bakllava", temperature=0) msg = chat.invoke( [ HumanMessage( content=[ {"type": "text", "text": prompt}, { "type": "image_url", "image_url": f"data:image/jpeg;base64,{img_base64}", }, ] ) ] ) return msg.content def generate_img_summaries(img_base64_list): """ Generate summaries for images :param img_base64_list: Base64 encoded images :return: List of image summaries and processed images """ # Store image summaries image_summaries = [] processed_images = [] # Prompt prompt = """Give a detailed summary of the image.""" # Apply summarization to images for i, base64_image in enumerate(img_base64_list): try: image_summaries.append(image_summarize(base64_image, prompt)) processed_images.append(base64_image) except Exception as e: print(f"Error with image {i+1}: {e}") return image_summaries, processed_images def get_images(img_path): """ Extract images. :param img_path: A string representing the path to the images. """ # Get image URIs pil_images = [ Image.open(os.path.join(img_path, image_name)) for image_name in os.listdir(img_path) if image_name.endswith(".jpg") ] return pil_images def resize_base64_image(base64_string, size=(128, 128)): """ Resize an image encoded as a Base64 string :param base64_string: Base64 string :param size: Image size :return: Re-sized Base64 string """ # Decode the Base64 string img_data = base64.b64decode(base64_string) img = Image.open(io.BytesIO(img_data)) # Resize the image resized_img = img.resize(size, Image.LANCZOS) # Save the resized image to a bytes buffer buffered = io.BytesIO() resized_img.save(buffered, format=img.format) # Encode the resized image to Base64 return base64.b64encode(buffered.getvalue()).decode("utf-8") def convert_to_base64(pil_image): """ Convert PIL images to Base64 encoded strings :param pil_image: PIL image :return: Re-sized Base64 string """ buffered = BytesIO() pil_image.save(buffered, format="JPEG") # You can change the format if needed img_str = base64.b64encode(buffered.getvalue()).decode("utf-8") # img_str = resize_base64_image(img_str, size=(831,623)) return img_str def create_multi_vector_retriever(vectorstore, image_summaries, images): """ Create retriever that indexes summaries, but returns raw images or texts :param vectorstore: Vectorstore to store embedded image sumamries :param image_summaries: Image summaries :param images: Base64 encoded images :return: Retriever """ # Initialize the storage layer for images store = LocalFileStore( str(Path(__file__).parent / "multi_vector_retriever_metadata") ) id_key = "doc_id" # Create the multi-vector retriever retriever = MultiVectorRetriever( vectorstore=vectorstore, byte_store=store, id_key=id_key, ) # Helper function to add documents to the vectorstore and docstore def add_documents(retriever, doc_summaries, doc_contents): doc_ids = [str(uuid.uuid4()) for _ in doc_contents] summary_docs = [ Document(page_content=s, metadata={id_key: doc_ids[i]}) for i, s in enumerate(doc_summaries) ] retriever.vectorstore.add_documents(summary_docs) retriever.docstore.mset(list(zip(doc_ids, doc_contents))) add_documents(retriever, image_summaries, images) return retriever # Load images doc_path = Path(__file__).parent / "docs/" rel_doc_path = doc_path.relative_to(Path.cwd()) print("Read images") pil_images = get_images(rel_doc_path) # Convert to b64 images_base_64 = [convert_to_base64(i) for i in pil_images] # Image summaries print("Generate image summaries") image_summaries, images_base_64_processed = generate_img_summaries(images_base_64) # The vectorstore to use to index the images summaries vectorstore_mvr = Chroma( collection_name="image_summaries", persist_directory=str(Path(__file__).parent / "chroma_db_multi_modal"), embedding_function=OllamaEmbeddings(model="llama2:7b"), ) # Create documents images_base_64_processed_documents = [ Document(page_content=i) for i in images_base_64_processed ] # Create retriever retriever_multi_vector_img = create_multi_vector_retriever( vectorstore_mvr, image_summaries, images_base_64_processed_documents, )