quant script
#1
by
prudant
- opened
hI! can you share your quant script? i want to quant and share ocrflux but never before make quants of VLMs
Thanks!
Sorry for the late response!
Here’s my script for quantizing a VLM. You should run calibration on your own dataset (the one you’ll actually use the model on):
import base64
from io import BytesIO
import torch
from datasets import load_dataset
from qwen_vl_utils import process_vision_info
from transformers import AutoProcessor, Qwen2_5_VLForConditionalGeneration
from llmcompressor.modifiers.quantization import QuantizationModifier
from llmcompressor.modifiers.quantization import GPTQModifier
from llmcompressor import oneshot
from llmcompressor.utils import dispatch_for_generation
from compressed_tensors.quantization.quant_args import (
QuantizationArgs,
QuantizationStrategy,
QuantizationType,
)
# Load model.
model_id = "nanonets/Nanonets-OCR-s"
model = Qwen2_5_VLForConditionalGeneration.from_pretrained(model_id, torch_dtype="auto")
processor = AutoProcessor.from_pretrained(model_id, trust_remote_code=True)
# Oneshot arguments
DATASET_ID = "nielsr/funsd"
DATASET_SPLIT = "train[:512]"
NUM_CALIBRATION_SAMPLES = 512
MAX_SEQUENCE_LENGTH = 10000
# Load dataset and preprocess.
ds = load_dataset(DATASET_ID, split=DATASET_SPLIT)
ds = ds.shuffle(seed=42)
# Apply chat template and tokenize inputs.
def preprocess_and_tokenize(example):
# preprocess
buffered = BytesIO()
example["image"].save(buffered, format="PNG")
encoded_image = base64.b64encode(buffered.getvalue())
encoded_image_text = encoded_image.decode("utf-8")
base64_qwen = f"data:image;base64,{encoded_image_text}"
messages = [
{
"role": "user",
"content": [
{"type": "image", "image": base64_qwen},
{"type": "text", "text": "Extract the text from the above document as if you were reading it naturally. Text extracted as Markdown format. Return the tables as htlm format."},
],
}
]
text = processor.apply_chat_template(
messages, tokenize=False, add_generation_prompt=True
)
image_inputs, video_inputs = process_vision_info(messages)
# tokenize
return processor(
text=[text],
images=image_inputs,
videos=video_inputs,
padding=False,
max_length=MAX_SEQUENCE_LENGTH,
truncation=True,
)
ds = ds.map(preprocess_and_tokenize, remove_columns=ds.column_names)
# Define a oneshot data collator for multimodal inputs.
def data_collator(batch):
assert len(batch) == 1
return {key: torch.tensor(value) for key, value in batch[0].items()}
# Recipe
recipe = [
GPTQModifier(
targets="Linear",
scheme="W8A8",
ignore=["lm_head", "re:visual.*", "re:model.visual.*"],
),
]
# Perform oneshot
oneshot(
model=model,
tokenizer=model_id,
dataset=ds,
recipe=recipe,
max_seq_length=MAX_SEQUENCE_LENGTH,
num_calibration_samples=NUM_CALIBRATION_SAMPLES,
trust_remote_code_model=True,
data_collator=data_collator,
)
# Confirm generations of the quantized model look sane.
print("========== SAMPLE GENERATION ==============")
dispatch_for_generation(model)
messages = [
{
"role": "user",
"content": [
{
"type": "image",
"image": "https://i1.rgstatic.net/publication/293322356_Are_Your_Digital_Documents_Web_Friendly_Making_Scanned_Documents_Web_Accessible/links/574846a408ae2301b0b97d32/largepreview.png",
},
{"type": "text", "text": "Extract the text from the above document as if you were reading it naturally. Text extracted as Markdown format. Return the tables as htlm format."},
],
}
]
prompt = processor.apply_chat_template(messages, add_generation_prompt=True)
image_inputs, video_inputs = process_vision_info(messages)
inputs = processor(
text=[prompt],
images=image_inputs,
videos=video_inputs,
padding=False,
max_length=MAX_SEQUENCE_LENGTH,
truncation=True,
return_tensors="pt",
).to("cuda")
output = model.generate(**inputs, max_new_tokens=100)
print(processor.decode(output[0], skip_special_tokens=True))
print("==========================================")
# Save to disk compressed.
SAVE_DIR = model_id.rstrip("/").split("/")[-1] + "-w8a8-1"
model.save_pretrained(SAVE_DIR, save_compressed=True)
processor.save_pretrained(SAVE_DIR)
thanks!