Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add finetuning tutorial #353

Draft
wants to merge 3 commits into
base: main
Choose a base branch
from
Draft
Show file tree
Hide file tree
Changes from all commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
360 changes: 360 additions & 0 deletions tutorials/generative/2d_ldm/2d_finetuning_stable_diffusion.ipynb
Original file line number Diff line number Diff line change
@@ -0,0 +1,360 @@
{
"cells": [
{
"cell_type": "code",
"execution_count": null,
"id": "734c91f1",
"metadata": {},
"outputs": [],
"source": [
"# Copyright (c) MONAI Consortium\n",
"# Licensed under the Apache License, Version 2.0 (the \"License\");\n",
"# you may not use this file except in compliance with the License.\n",
"# You may obtain a copy of the License at\n",
"# http://www.apache.org/licenses/LICENSE-2.0\n",
"# Unless required by applicable law or agreed to in writing, software\n",
"# distributed under the License is distributed on an \"AS IS\" BASIS,\n",
"# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.\n",
"# See the License for the specific language governing permissions and\n",
"# limitations under the License."
]
},
{
"cell_type": "markdown",
"id": "bb70a99f",
"metadata": {},
"source": [
"# Finetuning Stable Diffusion to Generate 2D Medical Images\n",
"\n",
"In this tutorial, we will convert the Stable Diffusion weights to be loaded using MONAI Generative Model classes. Next, we will use a similar approach presented in [1,2] and finetune (and train from scratch) the second stage of the latent diffusion model.\n",
"\n",
"[1] - Chambon et al. \"RoentGen: Vision-Language Foundation Model for Chest X-ray Generation.\" https://arxiv.org/abs/2211.12737\n",
"\n",
"[2] - Chambon et al. \"Adapting Pretrained Vision-Language Foundational Models to Medical Imaging Domains.\" https://arxiv.org/abs/2210.04133"
]
},
{
"cell_type": "markdown",
"id": "b97c43d9",
"metadata": {},
"source": [
"## Setup imports"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "57bd0843",
"metadata": {},
"outputs": [],
"source": [
"import os\n",
"import tempfile\n",
"import time\n",
"import os\n",
"import matplotlib.pyplot as plt\n",
"import numpy as np\n",
"import torch\n",
"import torch.nn.functional as F\n",
"import sys\n",
"from monai import transforms\n",
"from monai.apps import DecathlonDataset\n",
"from monai.config import print_config\n",
"from monai.data import DataLoader\n",
"from monai.utils import set_determinism\n",
"from torch.cuda.amp import GradScaler, autocast\n",
"from tqdm import tqdm\n",
"\n",
"from generative.networks.nets.diffusion_model_unet import DiffusionModelUNet\n",
"\n",
"print_config()"
]
},
{
"cell_type": "markdown",
"id": "df46172d",
"metadata": {},
"source": [
"### Setup data directory"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "a58dcafa",
"metadata": {},
"outputs": [],
"source": [
"directory = os.environ.get(\"MONAI_DATA_DIRECTORY\")\n",
"root_dir = tempfile.mkdtemp() if directory is None else directory"
]
},
{
"cell_type": "markdown",
"id": "880d3b1a",
"metadata": {},
"source": [
"### Set deterministic training for reproducibility"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "01459e7e",
"metadata": {},
"outputs": [],
"source": [
"set_determinism(42)"
]
},
{
"cell_type": "markdown",
"id": "22aa0d4b",
"metadata": {},
"source": [
"## Setup BRATS Dataset - Transforms for extracting 2D slices from 3D volumes\n",
"\n",
"We now download the BraTS dataset and extract the 2D slices from the 3D volumes. The `slice_label` is used to indicate whether the slice contains an anomaly or not.\n",
"\n",
"Here we use transforms to augment the training dataset, as usual:\n",
"\n",
"1. `LoadImaged` loads the brain images from files.\n",
"2. `EnsureChannelFirstd` ensures the original data to construct \"channel first\" shape.\n",
"3. The first `Lambdad` transform chooses the first channel of the image, which is the T1-weighted image.\n",
"4. `Spacingd` resamples the image to the specified voxel spacing, we use 3,3,2 mm to match the original paper.\n",
"5. `ScaleIntensityRangePercentilesd` Apply range scaling to a numpy array based on the intensity distribution of the input. Transform is very common with MRI images.\n",
"6. `RandSpatialCropd` randomly crop out a 2D patch from the 3D image.\n",
"6. The last `Lambdad` transform obtains `slice_label` by summing up the label to have a single scalar value (healthy `=1` or not `=2` )."
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "2ffea194",
"metadata": {},
"outputs": [],
"source": [
"channel = 0 # 0 = Flair\n",
"assert channel in [0, 1, 2, 3], \"Choose a valid channel\"\n",
"\n",
"train_transforms = transforms.Compose(\n",
" [\n",
" transforms.LoadImaged(keys=[\"image\", \"label\"]),\n",
" transforms.EnsureChannelFirstd(keys=[\"image\", \"label\"]),\n",
" transforms.Lambdad(keys=[\"image\"], func=lambda x: x[channel, :, :, :]),\n",
" transforms.AddChanneld(keys=[\"image\"]),\n",
" transforms.EnsureTyped(keys=[\"image\", \"label\"]),\n",
" transforms.Orientationd(keys=[\"image\", \"label\"], axcodes=\"RAS\"),\n",
" transforms.Spacingd(keys=[\"image\", \"label\"], pixdim=(3.0, 3.0, 2.0), mode=(\"bilinear\", \"nearest\")),\n",
" transforms.CenterSpatialCropd(keys=[\"image\", \"label\"], roi_size=(64, 64, 44)),\n",
" transforms.ScaleIntensityRangePercentilesd(keys=\"image\", lower=0, upper=99.5, b_min=0, b_max=1),\n",
" transforms.RandSpatialCropd(keys=[\"image\", \"label\"], roi_size=(64, 64, 1), random_size=False),\n",
" transforms.Lambdad(keys=[\"image\", \"label\"], func=lambda x: x.squeeze(-1)),\n",
" transforms.CopyItemsd(keys=[\"label\"], times=1, names=[\"slice_label\"]),\n",
" transforms.Lambdad(keys=[\"slice_label\"], func=lambda x: 2.0 if x.sum() > 0 else 1.0),\n",
" ]\n",
")"
]
},
{
"cell_type": "markdown",
"id": "94518df7",
"metadata": {},
"source": [
"### Load Training and Validation Datasets"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "ce3e3517",
"metadata": {},
"outputs": [],
"source": [
"train_ds = DecathlonDataset(\n",
" root_dir=root_dir,\n",
" task=\"Task01_BrainTumour\",\n",
" section=\"training\",\n",
" cache_rate=1.0, # you may need a few Gb of RAM... Set to 0 otherwise\n",
" num_workers=4,\n",
" download=False, # Set download to True if the dataset hasnt been downloaded yet\n",
" seed=0,\n",
" transform=train_transforms,\n",
")\n",
"print(f\"Length of training data: {len(train_ds)}\")\n",
"print(f'Train image shape {train_ds[0][\"image\"].shape}')\n",
"\n",
"val_ds = DecathlonDataset(\n",
" root_dir=root_dir,\n",
" task=\"Task01_BrainTumour\",\n",
" section=\"validation\",\n",
" cache_rate=1.0, # you may need a few Gb of RAM... Set to 0 otherwise\n",
" num_workers=4,\n",
" download=False, # Set download to True if the dataset hasnt been downloaded yet\n",
" seed=0,\n",
" transform=train_transforms,\n",
")\n",
"print(f\"Length of training data: {len(val_ds)}\")\n",
"print(f'Validation Image shape {val_ds[0][\"image\"].shape}')"
]
},
{
"cell_type": "markdown",
"id": "18394239",
"metadata": {},
"source": [
"## Converting Stable Diffusion weights"
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "b77aca02",
"metadata": {},
"outputs": [],
"source": []
},
{
"cell_type": "markdown",
"id": "8830c874",
"metadata": {},
"source": [
"## Finetuning Diffusion Model\n",
"\n",
"At this step, we instantiate the MONAI components to create a DDIM, the UNET with conditioning, the noise scheduler, and the inferer used for training and sampling. We are using\n",
"the deterministic DDIM scheduler containing 1000 timesteps, and a 2D UNET with attention mechanisms.\n",
"\n",
"The `attention` mechanism is essential for ensuring good conditioning and images manipulation here.\n",
"\n",
"An `embedding layer`, which is also optimised during training, is used in the original work because it was empirically shown to improve conditioning compared to a single scalar information."
]
},
{
"cell_type": "code",
"execution_count": null,
"id": "a52880db",
"metadata": {},
"outputs": [],
"source": [
"condition_dropout = 0.15\n",
"n_iterations = 2e4\n",
"batch_size = 64\n",
"val_interval = 100\n",
"iter_loss_list = []\n",
"val_iter_loss_list = []\n",
"iterations = []\n",
"iteration = 0\n",
"iter_loss = 0\n",
"\n",
"train_loader = DataLoader(\n",
" train_ds, batch_size=batch_size, shuffle=True, num_workers=4, drop_last=True, persistent_workers=True\n",
")\n",
"val_loader = DataLoader(\n",
" val_ds, batch_size=batch_size, shuffle=False, num_workers=4, drop_last=True, persistent_workers=True\n",
")\n",
"\n",
"scaler = GradScaler()\n",
"total_start = time.time()\n",
"\n",
"while iteration < n_iterations:\n",
" for batch in train_loader:\n",
" iteration += 1\n",
" model.train()\n",
" images, classes = batch[\"image\"].to(device), batch[\"slice_label\"].to(device)\n",
" # 15% of the time, class conditioning dropout\n",
" classes = classes * (torch.rand_like(classes) > condition_dropout)\n",
" # cross attention expects shape [batch size, sequence length, channels]\n",
" class_embedding = embed(classes.long().to(device)).unsqueeze(1)\n",
" optimizer.zero_grad(set_to_none=True)\n",
" # pick a random time step t\n",
" timesteps = torch.randint(0, 1000, (len(images),)).to(device)\n",
"\n",
" with autocast(enabled=True):\n",
" # Generate random noise\n",
" noise = torch.randn_like(images).to(device)\n",
" # Get model prediction\n",
" noise_pred = inferer(\n",
" inputs=images, diffusion_model=model, noise=noise, timesteps=timesteps, condition=class_embedding\n",
" )\n",
" loss = F.mse_loss(noise_pred.float(), noise.float())\n",
"\n",
" scaler.scale(loss).backward()\n",
" scaler.step(optimizer)\n",
" scaler.update()\n",
" iter_loss += loss.item()\n",
" sys.stdout.write(f\"Iteration {iteration}/{n_iterations} - train Loss {loss.item():.4f}\" + \"\\r\")\n",
" sys.stdout.flush()\n",
"\n",
" if (iteration) % val_interval == 0:\n",
" model.eval()\n",
" val_iter_loss = 0\n",
" for val_step, val_batch in enumerate(val_loader):\n",
" images, classes = val_batch[\"image\"].to(device), val_batch[\"slice_label\"].to(device)\n",
" # cross attention expects shape [batch size, sequence length, channels]\n",
" class_embedding = embed(classes.long().to(device)).unsqueeze(1)\n",
" timesteps = torch.randint(0, 1000, (len(images),)).to(device)\n",
" with torch.no_grad():\n",
" with autocast(enabled=True):\n",
" noise = torch.randn_like(images).to(device)\n",
" noise_pred = inferer(\n",
" inputs=images,\n",
" diffusion_model=model,\n",
" noise=noise,\n",
" timesteps=timesteps,\n",
" condition=class_embedding,\n",
" )\n",
" val_loss = F.mse_loss(noise_pred.float(), noise.float())\n",
" val_iter_loss += val_loss.item()\n",
" iter_loss_list.append(iter_loss / val_interval)\n",
" val_iter_loss_list.append(val_iter_loss / (val_step + 1))\n",
" iterations.append(iteration)\n",
" iter_loss = 0\n",
" print(\n",
" f\"Train Loss {loss.item():.4f}, Interval Loss {iter_loss_list[-1]:.4f}, Interval Loss Val {val_iter_loss_list[-1]:.4f}\"\n",
" )\n",
"\n",
"\n",
"total_time = time.time() - total_start\n",
"\n",
"print(f\"train diffusion completed, total time: {total_time}.\")\n",
"\n",
"plt.style.use(\"seaborn-bright\")\n",
"plt.title(\"Learning Curves Diffusion Model\", fontsize=20)\n",
"plt.plot(iterations, iter_loss_list, color=\"C0\", linewidth=2.0, label=\"Train\")\n",
"plt.plot(\n",
" iterations, val_iter_loss_list, color=\"C1\", linewidth=2.0, label=\"Validation\"\n",
") # np.linspace(1, n_iterations, len(val_iter_loss_list))\n",
"plt.yticks(fontsize=12), plt.xticks(fontsize=12)\n",
"plt.xlabel(\"Iterations\", fontsize=16), plt.ylabel(\"Loss\", fontsize=16)\n",
"plt.legend(prop={\"size\": 14})\n",
"plt.show()"
]
}
],
"metadata": {
"jupytext": {
"cell_metadata_filter": "-all",
"formats": "auto:light,ipynb",
"notebook_metadata_filter": "-all"
},
"kernelspec": {
"display_name": "Python 3 (ipykernel)",
"language": "python",
"name": "python3"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 3
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.10.6"
}
},
"nbformat": 4,
"nbformat_minor": 5
}
Loading