faiss_rag_enterprise/llama_index/readers/file/slides_reader.py

114 lines
3.5 KiB
Python

"""Slides parser.
Contains parsers for .pptx files.
"""
import os
from pathlib import Path
from typing import Dict, List, Optional
from llama_index.readers.base import BaseReader
from llama_index.schema import Document
from llama_index.utils import infer_torch_device
class PptxReader(BaseReader):
"""Powerpoint parser.
Extract text, caption images, and specify slides.
"""
def __init__(self) -> None:
"""Init parser."""
try:
import torch # noqa
from PIL import Image # noqa
from pptx import Presentation # noqa
from transformers import (
AutoTokenizer,
VisionEncoderDecoderModel,
ViTFeatureExtractor,
)
except ImportError:
raise ImportError(
"Please install extra dependencies that are required for "
"the PptxReader: "
"`pip install torch transformers python-pptx Pillow`"
)
model = VisionEncoderDecoderModel.from_pretrained(
"nlpconnect/vit-gpt2-image-captioning"
)
feature_extractor = ViTFeatureExtractor.from_pretrained(
"nlpconnect/vit-gpt2-image-captioning"
)
tokenizer = AutoTokenizer.from_pretrained(
"nlpconnect/vit-gpt2-image-captioning"
)
self.parser_config = {
"feature_extractor": feature_extractor,
"model": model,
"tokenizer": tokenizer,
}
def caption_image(self, tmp_image_file: str) -> str:
"""Generate text caption of image."""
from PIL import Image
model = self.parser_config["model"]
feature_extractor = self.parser_config["feature_extractor"]
tokenizer = self.parser_config["tokenizer"]
device = infer_torch_device()
model.to(device)
max_length = 16
num_beams = 4
gen_kwargs = {"max_length": max_length, "num_beams": num_beams}
i_image = Image.open(tmp_image_file)
if i_image.mode != "RGB":
i_image = i_image.convert(mode="RGB")
pixel_values = feature_extractor(
images=[i_image], return_tensors="pt"
).pixel_values
pixel_values = pixel_values.to(device)
output_ids = model.generate(pixel_values, **gen_kwargs)
preds = tokenizer.batch_decode(output_ids, skip_special_tokens=True)
return preds[0].strip()
def load_data(
self,
file: Path,
extra_info: Optional[Dict] = None,
) -> List[Document]:
"""Parse file."""
from pptx import Presentation
presentation = Presentation(file)
result = ""
for i, slide in enumerate(presentation.slides):
result += f"\n\nSlide #{i}: \n"
for shape in slide.shapes:
if hasattr(shape, "image"):
image = shape.image
# get image "file" contents
image_bytes = image.blob
# temporarily save the image to feed into model
image_filename = f"tmp_image.{image.ext}"
with open(image_filename, "wb") as f:
f.write(image_bytes)
result += f"\n Image: {self.caption_image(image_filename)}\n\n"
os.remove(image_filename)
if hasattr(shape, "text"):
result += f"{shape.text}\n"
return [Document(text=result, metadata=extra_info or {})]