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llama-3-vision-alpha / __main__.py
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import argparse
import sys
import torch
import torch.nn as nn
from PIL import Image
from transformers import (
AutoTokenizer,
BitsAndBytesConfig,
LlamaForCausalLM,
SiglipImageProcessor,
SiglipVisionModel,
)
from transformers import TextStreamer
def tokenizer_image_token(prompt, tokenizer, image_token_index=-200):
prompt_chunks = prompt.split("<image>")
tokenized_chunks = [tokenizer(chunk).input_ids for chunk in prompt_chunks]
input_ids = tokenized_chunks[0]
for chunk in tokenized_chunks[1:]:
input_ids.append(image_token_index)
input_ids.extend(chunk[1:]) # Exclude BOS token on nonzero index
return torch.tensor(input_ids, dtype=torch.long)
def process_tensors(input_ids, image_features, embedding_layer):
# Find the index of -200 in input_ids
split_index = (input_ids == -200).nonzero(as_tuple=True)[1][0]
# Split the input_ids at the index found, excluding -200
input_ids_1 = input_ids[:, :split_index]
input_ids_2 = input_ids[:, split_index + 1 :]
# Convert input_ids to embeddings
embeddings_1 = embedding_layer(input_ids_1)
embeddings_2 = embedding_layer(input_ids_2)
device = image_features.device
token_embeddings_part1 = embeddings_1.to(device)
token_embeddings_part2 = embeddings_2.to(device)
# Concatenate the token embeddings and image features
concatenated_embeddings = torch.cat(
[token_embeddings_part1, image_features, token_embeddings_part2], dim=1
)
# Create the corrected attention mask
attention_mask = torch.ones(
concatenated_embeddings.shape[:2], dtype=torch.long, device=device
)
return concatenated_embeddings, attention_mask
def initialize_models():
bnb_config = BitsAndBytesConfig(
load_in_4bit=True, bnb_4bit_compute_dtype=torch.float16
)
tokenizer = AutoTokenizer.from_pretrained(
"unsloth/llama-3-8b-Instruct", use_fast=True
)
model = LlamaForCausalLM.from_pretrained(
"unsloth/llama-3-8b-Instruct",
torch_dtype=torch.float16,
device_map="auto",
quantization_config=bnb_config,
)
for param in model.base_model.parameters():
param.requires_grad = False
model_name = "google/siglip-so400m-patch14-384"
vision_model = SiglipVisionModel.from_pretrained(
model_name, torch_dtype=torch.float16
)
processor = SiglipImageProcessor.from_pretrained(model_name)
vision_model = vision_model.to("cuda")
return tokenizer, model, vision_model, processor
class ProjectionModule(nn.Module):
def __init__(self, mm_hidden_size, hidden_size):
super(ProjectionModule, self).__init__()
# Directly set up the sequential model
self.model = nn.Sequential(
nn.Linear(mm_hidden_size, hidden_size),
nn.GELU(),
nn.Linear(hidden_size, hidden_size),
)
def forward(self, x):
return self.model(x)
def load_projection_module(mm_hidden_size=1152, hidden_size=4096, device="cuda"):
projection_module = ProjectionModule(mm_hidden_size, hidden_size)
checkpoint = torch.load("./mm_projector.bin")
checkpoint = {k.replace("mm_projector.", ""): v for k, v in checkpoint.items()}
projection_module.load_state_dict(checkpoint)
projection_module = projection_module.to(device).half()
return projection_module
def answer_question(
image_path, tokenizer, model, vision_model, processor, projection_module
):
image = Image.open(image_path).convert("RGB")
tokenizer.eos_token = "<|eot_id|>"
try:
q = input("\nuser: ")
except EOFError:
q = ""
if not q:
print("no input detected. exiting.")
sys.exit()
question = "<image>" + q
prompt = f"<|start_header_id|>user<|end_header_id|>\n\n{question}<|eot_id|><|start_header_id|>assistant<|end_header_id|>\n\n"
input_ids = (
tokenizer_image_token(prompt, tokenizer)
.unsqueeze(0)
.to(model.device)
)
streamer = TextStreamer(tokenizer, skip_prompt=True, skip_special_tokens=True)
with torch.inference_mode():
image_inputs = processor(
images=[image],
return_tensors="pt",
do_resize=True,
size={"height": 384, "width": 384},
).to("cuda")
image_inputs = image_inputs["pixel_values"].squeeze(0)
image_forward_outs = vision_model(
image_inputs.to(device="cuda", dtype=torch.float16).unsqueeze(0),
output_hidden_states=True,
)
image_features = image_forward_outs.hidden_states[-2]
projected_embeddings = projection_module(image_features).to("cuda")
embedding_layer = model.get_input_embeddings()
# text_embeddings = embedding_layer(input_ids)
new_embeds, attn_mask = process_tensors(
input_ids, projected_embeddings, embedding_layer
)
device = model.device
attn_mask = attn_mask.to(device)
new_embeds = new_embeds.to(device)
model_kwargs = {
"do_sample": True,
"temperature": 0.2,
"max_new_tokens": 2000,
"use_cache": True,
"streamer": streamer,
"pad_token_id": tokenizer.eos_token_id
}
while True:
print('assistant: ')
generated_ids = model.generate(
inputs_embeds=new_embeds, attention_mask=attn_mask, **model_kwargs
)[0]
generated_text = tokenizer.decode(generated_ids, skip_special_tokens=False)
try:
q = input("\nuser: ")
except EOFError:
q = ""
if not q:
print("no input detected. exiting.")
new_text = (
generated_text
+ "<|start_header_id|>user<|end_header_id|>\n\n"
+ q
+ "<|start_header_id|>assistant<|end_header_id|>\n\n"
)
new_input_ids = tokenizer(new_text, return_tensors="pt").input_ids.to(
device
)
new_embeddings = embedding_layer(new_input_ids)
new_embeds = torch.cat([new_embeds, new_embeddings], dim=1)
attn_mask = torch.ones(new_embeds.shape[:2], device=device)
if __name__ == "__main__":
parser = argparse.ArgumentParser(description="Answer questions based on an image")
parser.add_argument("-i", "--image", required=True, help="Path to the image file")
args = parser.parse_args()
tokenizer, model, vision_model, processor = initialize_models()
projection_module = load_projection_module()
answer_question(
args.image,
tokenizer,
model,
vision_model,
processor,
projection_module,
)