FLUX.2 launch

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timudk
2025-11-25 07:25:25 -08:00
commit e80b84ed9f
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from pathlib import Path
import torch
import torch.nn as nn
from einops import rearrange
from PIL import Image
from transformers import AutoProcessor, Mistral3ForConditionalGeneration, pipeline
from .sampling import cap_pixels, concatenate_images
from .system_messages import (
PROMPT_IMAGE_INTEGRITY,
PROMPT_IMAGE_INTEGRITY_FOLLOW_UP,
PROMPT_TEXT_INTEGRITY,
SYSTEM_MESSAGE,
SYSTEM_MESSAGE_UPSAMPLING_I2I,
SYSTEM_MESSAGE_UPSAMPLING_T2I,
SYSTEM_PROMPT_CONTENT_FILTER,
)
OUTPUT_LAYERS = [10, 20, 30]
MAX_LENGTH = 512
NSFW_THRESHOLD = 0.85
UPSAMPLING_MAX_IMAGE_SIZE = 768**2
class Mistral3SmallEmbedder(nn.Module):
def __init__(
self,
model_spec: str = "mistralai/Mistral-Small-3.2-24B-Instruct-2506",
model_spec_processor: str = "mistralai/Mistral-Small-3.1-24B-Instruct-2503",
torch_dtype: str = "bfloat16",
):
super().__init__()
self.model: Mistral3ForConditionalGeneration = Mistral3ForConditionalGeneration.from_pretrained(
model_spec,
torch_dtype=getattr(torch, torch_dtype),
)
self.processor = AutoProcessor.from_pretrained(model_spec_processor, use_fast=False)
self.yes_token, self.no_token = self.processor.tokenizer.encode(
["yes", "no"], add_special_tokens=False
)
self.max_length = MAX_LENGTH
self.upsampling_max_image_size = UPSAMPLING_MAX_IMAGE_SIZE
self.nsfw_classifier = pipeline("image-classification", model="Falconsai/nsfw_image_detection")
def _validate_and_process_images(
self, img: list[list[Image.Image]] | list[Image.Image]
) -> list[list[Image.Image]]:
# Simple validation: ensure it's a list of PIL images or list of lists of PIL images
if not img:
return []
# Check if it's a list of lists or a list of images
if isinstance(img[0], Image.Image):
# It's a list of images, convert to list of lists
img = [[im] for im in img]
# potentially concatenate multiple images to reduce the size
img = [[concatenate_images(img_i)] if len(img_i) > 1 else img_i for img_i in img]
# cap the pixels
img = [[cap_pixels(img_i, self.upsampling_max_image_size) for img_i in img_i] for img_i in img]
return img
def format_input(
self,
txt: list[str],
system_message: str = SYSTEM_MESSAGE,
img: list[Image.Image] | list[list[Image.Image]] | None = None,
) -> list[list[dict]]:
"""
Format a batch of text prompts into the conversation format expected by apply_chat_template.
Optionally, add images to the input.
Args:
txt: List of text prompts
system_message: System message to use (default: CREATIVE_SYSTEM_MESSAGE)
img: List of images to add to the input.
Returns:
List of conversations, where each conversation is a list of message dicts
"""
# Remove [IMG] tokens from prompts to avoid Pixtral validation issues
# when truncation is enabled. The processor counts [IMG] tokens and fails
# if the count changes after truncation.
cleaned_txt = [prompt.replace("[IMG]", "") for prompt in txt]
if img is None or len(img) == 0:
return [
[
{
"role": "system",
"content": [{"type": "text", "text": system_message}],
},
{"role": "user", "content": [{"type": "text", "text": prompt}]},
]
for prompt in cleaned_txt
]
else:
assert len(img) == len(txt), "Number of images must match number of prompts"
img = self._validate_and_process_images(img)
messages = [
[
{
"role": "system",
"content": [{"type": "text", "text": system_message}],
},
]
for _ in cleaned_txt
]
for i, (el, images) in enumerate(zip(messages, img)):
# optionally add the images per batch element.
if images is not None:
el.append(
{
"role": "user",
"content": [{"type": "image", "image": image_obj} for image_obj in images],
}
)
# add the text.
el.append(
{
"role": "user",
"content": [{"type": "text", "text": cleaned_txt[i]}],
}
)
return messages
@torch.no_grad()
def upsample_prompt(
self,
txt: list[str],
img: list[Image.Image] | list[list[Image.Image]] | None = None,
temperature: float = 0.15,
) -> list[str]:
"""
Upsample prompts using the model's generate method.
Args:
txt: List of input prompts to upsample
img: Optional list of images or list of lists of images. If None or all None, uses t2i mode, otherwise i2i mode.
Returns:
List of upsampled prompts
"""
# Set system message based on whether images are provided
if img is None or len(img) == 0 or img[0] is None:
system_message = SYSTEM_MESSAGE_UPSAMPLING_T2I
else:
system_message = SYSTEM_MESSAGE_UPSAMPLING_I2I
# Format input messages
messages_batch = self.format_input(txt=txt, system_message=system_message, img=img)
# Process all messages at once
# with image processing a too short max length can throw an error in here.
try:
inputs = self.processor.apply_chat_template(
messages_batch,
add_generation_prompt=True,
tokenize=True,
return_dict=True,
return_tensors="pt",
padding="max_length",
truncation=True,
max_length=2048,
)
except ValueError as e:
print(
f"Error processing input: {e}, your max length is probably too short, when you have images in the input."
)
raise e
# Move to device
inputs["input_ids"] = inputs["input_ids"].to(self.model.device)
inputs["attention_mask"] = inputs["attention_mask"].to(self.model.device)
if "pixel_values" in inputs:
inputs["pixel_values"] = inputs["pixel_values"].to(self.model.device, self.model.dtype)
# Generate text using the model's generate method
try:
generated_ids = self.model.generate(
**inputs,
max_new_tokens=512,
do_sample=True,
temperature=temperature,
use_cache=True,
)
# Decode only the newly generated tokens (skip input tokens)
# Extract only the generated portion
input_length = inputs["input_ids"].shape[1]
generated_tokens = generated_ids[:, input_length:]
raw_txt = self.processor.tokenizer.batch_decode(
generated_tokens, skip_special_tokens=True, clean_up_tokenization_spaces=True
)
return raw_txt
except Exception as e:
print(f"Error generating upsampled prompt: {e}, returning original prompt")
return txt
@torch.no_grad()
def forward(self, txt: list[str]):
# Format input messages
messages_batch = self.format_input(txt=txt)
# Process all messages at once
# with image processing a too short max length can throw an error in here.
inputs = self.processor.apply_chat_template(
messages_batch,
add_generation_prompt=False,
tokenize=True,
return_dict=True,
return_tensors="pt",
padding="max_length",
truncation=True,
max_length=self.max_length,
)
# Move to device
input_ids = inputs["input_ids"].to(self.model.device)
attention_mask = inputs["attention_mask"].to(self.model.device)
# Forward pass through the model
output = self.model(
input_ids=input_ids,
attention_mask=attention_mask,
output_hidden_states=True,
use_cache=False,
)
out = torch.stack([output.hidden_states[k] for k in OUTPUT_LAYERS], dim=1)
return rearrange(out, "b c l d -> b l (c d)")
def yes_no_logit_processor(
self, input_ids: torch.LongTensor, scores: torch.FloatTensor
) -> torch.FloatTensor:
"""
Sets all tokens but yes/no to the minimum.
"""
scores_yes_token = scores[:, self.yes_token].clone()
scores_no_token = scores[:, self.no_token].clone()
scores_min = scores.min()
scores[:, :] = scores_min - 1
scores[:, self.yes_token] = scores_yes_token
scores[:, self.no_token] = scores_no_token
return scores
def test_image(self, image: Image.Image | str | Path | torch.Tensor) -> bool:
if isinstance(image, torch.Tensor):
image = rearrange(image[0].clamp(-1.0, 1.0), "c h w -> h w c")
image = Image.fromarray((127.5 * (image + 1.0)).cpu().byte().numpy())
elif isinstance(image, (str, Path)):
image = Image.open(image)
classification = next(c for c in self.nsfw_classifier(image) if c["label"] == "nsfw")
if classification["score"] > NSFW_THRESHOLD:
return True
# 512^2 pixels are enough for checking
w, h = image.size
f = (512**2 / (w * h)) ** 0.5
image = image.resize((int(f * w), int(f * h)))
chat = [
{
"role": "system",
"content": [
{
"type": "text",
"text": SYSTEM_PROMPT_CONTENT_FILTER,
},
],
},
{
"role": "user",
"content": [
{
"type": "text",
"text": PROMPT_IMAGE_INTEGRITY,
},
{
"type": "image",
"image": image,
},
{
"type": "text",
"text": PROMPT_IMAGE_INTEGRITY_FOLLOW_UP,
},
],
},
]
inputs = self.processor.apply_chat_template(
chat,
add_generation_prompt=True,
tokenize=True,
return_dict=True,
return_tensors="pt",
).to(self.model.device)
inputs["pixel_values"] = inputs["pixel_values"].to(dtype=self.model.dtype)
generate_ids = self.model.generate(
**inputs,
max_new_tokens=1,
logits_processor=[self.yes_no_logit_processor],
do_sample=False,
)
return generate_ids[0, -1].item() == self.yes_token
def test_txt(self, txt: str) -> bool:
chat = [
{
"role": "system",
"content": [
{
"type": "text",
"text": SYSTEM_PROMPT_CONTENT_FILTER,
},
],
},
{
"role": "user",
"content": [
{
"type": "text",
"text": PROMPT_TEXT_INTEGRITY.format(prompt=txt),
},
],
},
]
inputs = self.processor.apply_chat_template(
chat,
add_generation_prompt=True,
tokenize=True,
return_dict=True,
return_tensors="pt",
).to(self.model.device)
generate_ids = self.model.generate(
**inputs,
max_new_tokens=1,
logits_processor=[self.yes_no_logit_processor],
do_sample=False,
)
return generate_ids[0, -1].item() == self.yes_token