v1.0

README.md

@@ -1,2 +1,95 @@
-# RETFound_MAE
+## RETFound - A foundation model for retinal image
-RETFound - A foundation model for retinal image
+
+
+This is official repo for RETFound, which heavily bases on [MAE](https://github.com/facebookresearch/mae):
+
+
+### Key features
+
+- RETFound was trained on 1.6 million retinal images
+- RETFound has been validated in multiple disease detection tasks
+- RETFound can be efficiently adapted to customised task
+
+
+### Install enviroment
+
+Create enviroment with conda:
+
+```
+conda create -n retfound python=3.6.15 -y
+```
+
+Install Pytorch 1.81 (cuda 11.1)
+```
+pip install torch==1.8.1+cu111 torchvision==0.9.1+cu111 torchaudio==0.8.1 -f https://download.pytorch.org/whl/torch_stable.html
+```
+
+Install others
+```
+pip install -r requirement.txt
+```
+
+
+### Fine-tuning with RETFound weights
+
+- RETFound pre-trained weights
+<table><tbody>
+<!-- START TABLE -->
+<!-- TABLE HEADER -->
+<th valign="bottom"></th>
+<th valign="bottom">ViT-Large</th>
+<!-- TABLE BODY -->
+<tr><td align="left">Colour fundus image</td>
+<td align="center"><a href="https://dl.fbaipublicfiles.com/mae/pretrain/mae_pretrain_vit_large.pth">download</a></td>
+</tr>
+<!-- TABLE BODY -->
+<tr><td align="left">OCT</td>
+<td align="center"><a href="https://dl.fbaipublicfiles.com/mae/pretrain/mae_pretrain_vit_large.pth">download</a></td>
+</tr>
+</tbody></table>
+
+- Organise data (use IDRiD as example)
+
+<p align="left">
+  <img src="https://user-images.githubusercontent.com/11435359/146857310-f258c86c-fde6-48e8-9cee-badd2b21bd2c.png" width="480">
+</p>
+
+
+- Start fine-tuning (use IDRiD as example). A fine-tuned checkpoint will be saved during training. Evaluation will be run after training.
+
+
+```
+python -m torch.distributed.launch --nproc_per_node=1 --master_port=48798 main_finetune.py  
+    --batch_size 16 \
+    --world_size 1 \
+    --model vit_large_patch16 \
+    --epochs 50 \
+    --blr 5e-3 --layer_decay 0.65 \
+    --weight_decay 0.05 --drop_path 0.2 \
+    --nb_classes 5 \
+    --data_path ./IDRiD_data/ \
+    --task ./finetune_IDRiD/ \
+    --finetune ./RETFound_cfp_weights.pth
+
+```
+
+
+- For evaluation only
+
+
+```
+python -m torch.distributed.launch --nproc_per_node=1 --master_port=48798 main_finetune.py 
+    --eval --batch_size 16 \
+    --world_size 1 \
+    --model vit_large_patch16 \
+    --epochs 40 \
+    --blr 5e-3 --layer_decay 0.65 \
+    --weight_decay 0.05 --drop_path 0.2 \
+    --nb_classes 5 \
+    --data_path ./IDRiD_data/ \
+    --task ./internal_IDRiD/ \
+    --resume ./finetune_IDRiD/checkpoint-best.pth
+
+```
+
+

engine_finetune.py

@@ -0,0 +1,214 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+# --------------------------------------------------------
+# References:
+# DeiT: https://github.com/facebookresearch/deit
+# BEiT: https://github.com/microsoft/unilm/tree/master/beit
+# --------------------------------------------------------
+
+import math
+import sys
+import csv
+import os
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+from timm.data import Mixup
+from timm.utils import accuracy
+from typing import Iterable, Optional
+import util.misc as misc
+import util.lr_sched as lr_sched
+from sklearn.metrics import accuracy_score, roc_auc_score, f1_score, average_precision_score,multilabel_confusion_matrix
+from pycm import *
+import matplotlib.pyplot as plt
+import numpy as np
+
+
+
+
+def misc_measures(confusion_matrix):
+    
+    acc = []
+    sensitivity = []
+    specificity = []
+    precision = []
+    G = []
+    F1_score_2 = []
+    mcc_ = []
+    
+    for i in range(1, confusion_matrix.shape[0]):
+        cm1=confusion_matrix[i]
+        acc.append(1.*(cm1[0,0]+cm1[1,1])/np.sum(cm1))
+        sensitivity_ = 1.*cm1[1,1]/(cm1[1,0]+cm1[1,1])
+        sensitivity.append(sensitivity_)
+        specificity_ = 1.*cm1[0,0]/(cm1[0,1]+cm1[0,0])
+        specificity.append(specificity_)
+        precision_ = 1.*cm1[1,1]/(cm1[1,1]+cm1[0,1])
+        precision.append(precision_)
+        G.append(np.sqrt(sensitivity_*specificity_))
+        F1_score_2.append(2*precision_*sensitivity_/(precision_+sensitivity_))
+        mcc = (cm1[0,0]*cm1[1,1]-cm1[0,1]*cm1[1,0])/np.sqrt((cm1[0,0]+cm1[0,1])*(cm1[0,0]+cm1[1,0])*(cm1[1,1]+cm1[1,0])*(cm1[1,1]+cm1[0,1]))
+        mcc_.append(mcc)
+        
+    acc = np.array(acc).mean()
+    sensitivity = np.array(sensitivity).mean()
+    specificity = np.array(specificity).mean()
+    precision = np.array(precision).mean()
+    G = np.array(G).mean()
+    F1_score_2 = np.array(F1_score_2).mean()
+    mcc_ = np.array(mcc_).mean()
+    
+    return acc, sensitivity, specificity, precision, G, F1_score_2, mcc_
+
+
+
+
+
+def train_one_epoch(model: torch.nn.Module, criterion: torch.nn.Module,
+                    data_loader: Iterable, optimizer: torch.optim.Optimizer,
+                    device: torch.device, epoch: int, loss_scaler, max_norm: float = 0,
+                    mixup_fn: Optional[Mixup] = None, log_writer=None,
+                    args=None):
+    model.train(True)
+    metric_logger = misc.MetricLogger(delimiter="  ")
+    metric_logger.add_meter('lr', misc.SmoothedValue(window_size=1, fmt='{value:.6f}'))
+    header = 'Epoch: [{}]'.format(epoch)
+    print_freq = 20
+
+    accum_iter = args.accum_iter
+
+    optimizer.zero_grad()
+
+    if log_writer is not None:
+        print('log_dir: {}'.format(log_writer.log_dir))
+
+    for data_iter_step, (samples, targets) in enumerate(metric_logger.log_every(data_loader, print_freq, header)):
+
+        # we use a per iteration (instead of per epoch) lr scheduler
+        if data_iter_step % accum_iter == 0:
+            lr_sched.adjust_learning_rate(optimizer, data_iter_step / len(data_loader) + epoch, args)
+
+        samples = samples.to(device, non_blocking=True)
+        targets = targets.to(device, non_blocking=True)
+
+        if mixup_fn is not None:
+            samples, targets = mixup_fn(samples, targets)
+
+        with torch.cuda.amp.autocast():
+            outputs = model(samples)
+            loss = criterion(outputs, targets)
+
+        loss_value = loss.item()
+
+        if not math.isfinite(loss_value):
+            print("Loss is {}, stopping training".format(loss_value))
+            sys.exit(1)
+
+        loss /= accum_iter
+        loss_scaler(loss, optimizer, clip_grad=max_norm,
+                    parameters=model.parameters(), create_graph=False,
+                    update_grad=(data_iter_step + 1) % accum_iter == 0)
+        if (data_iter_step + 1) % accum_iter == 0:
+            optimizer.zero_grad()
+
+        torch.cuda.synchronize()
+
+        metric_logger.update(loss=loss_value)
+        min_lr = 10.
+        max_lr = 0.
+        for group in optimizer.param_groups:
+            min_lr = min(min_lr, group["lr"])
+            max_lr = max(max_lr, group["lr"])
+
+        metric_logger.update(lr=max_lr)
+
+        loss_value_reduce = misc.all_reduce_mean(loss_value)
+        if log_writer is not None and (data_iter_step + 1) % accum_iter == 0:
+            """ We use epoch_1000x as the x-axis in tensorboard.
+            This calibrates different curves when batch size changes.
+            """
+            epoch_1000x = int((data_iter_step / len(data_loader) + epoch) * 1000)
+            log_writer.add_scalar('loss', loss_value_reduce, epoch_1000x)
+            log_writer.add_scalar('lr', max_lr, epoch_1000x)
+
+    # gather the stats from all processes
+    metric_logger.synchronize_between_processes()
+    print("Averaged stats:", metric_logger)
+    return {k: meter.global_avg for k, meter in metric_logger.meters.items()}
+
+
+
+
+@torch.no_grad()
+def evaluate(data_loader, model, device, task, epoch, mode, num_class):
+    criterion = torch.nn.CrossEntropyLoss()
+
+    metric_logger = misc.MetricLogger(delimiter="  ")
+    header = 'Test:'
+    
+    if not os.path.exists(task):
+        os.makedirs(task)
+
+    prediction_decode_list = []
+    prediction_list = []
+    true_label_decode_list = []
+    true_label_onehot_list = []
+    
+    # switch to evaluation mode
+    model.eval()
+
+    for batch in metric_logger.log_every(data_loader, 10, header):
+        images = batch[0]
+        target = batch[-1]
+        images = images.to(device, non_blocking=True)
+        target = target.to(device, non_blocking=True)
+        true_label=F.one_hot(target.to(torch.int64), num_classes=num_class)
+
+        # compute output
+        with torch.cuda.amp.autocast():
+            output = model(images)
+            loss = criterion(output, target)
+            prediction_softmax = nn.Softmax(dim=1)(output)
+            _,prediction_decode = torch.max(prediction_softmax, 1)
+            _,true_label_decode = torch.max(true_label, 1)
+
+            prediction_decode_list.extend(prediction_decode.cpu().detach().numpy())
+            true_label_decode_list.extend(true_label_decode.cpu().detach().numpy())
+            true_label_onehot_list.extend(true_label.cpu().detach().numpy())
+            prediction_list.extend(prediction_softmax.cpu().detach().numpy())
+
+        acc1,_ = accuracy(output, target, topk=(1,2))
+
+        batch_size = images.shape[0]
+        metric_logger.update(loss=loss.item())
+        metric_logger.meters['acc1'].update(acc1.item(), n=batch_size)
+    # gather the stats from all processes
+    true_label_decode_list = np.array(true_label_decode_list)
+    prediction_decode_list = np.array(prediction_decode_list)
+    confusion_matrix = multilabel_confusion_matrix(true_label_decode_list, prediction_decode_list,labels=[i for i in range(num_class)])
+    acc, sensitivity, specificity, precision, G, F1, mcc = misc_measures(confusion_matrix)
+    
+    auc_roc = roc_auc_score(true_label_onehot_list, prediction_list,multi_class='ovr',average='macro')
+    auc_pr = average_precision_score(true_label_onehot_list, prediction_list,average='macro')          
+            
+    metric_logger.synchronize_between_processes()
+    
+    print('Sklearn Metrics - Acc: {:.4f} AUC-roc: {:.4f} AUC-pr: {:.4f} F1-score: {:.4f} MCC: {:.4f}'.format(acc, auc_roc, auc_pr, F1, mcc)) 
+    results_path = task+'_metrics_{}.csv'.format(mode)
+    with open(results_path,mode='a',newline='',encoding='utf8') as cfa:
+        wf = csv.writer(cfa)
+        data2=[[acc,sensitivity,specificity,precision,auc_roc,auc_pr,F1,mcc,metric_logger.loss]]
+        for i in data2:
+            wf.writerow(i)
+            
+    
+    if mode=='test':
+        cm = ConfusionMatrix(actual_vector=true_label_decode_list, predict_vector=prediction_decode_list)
+        cm.plot(cmap=plt.cm.Blues,number_label=True,normalized=True,plot_lib="matplotlib")
+        plt.savefig(task+'confusion_matrix_test.jpg',dpi=600,bbox_inches ='tight')
+    
+    return {k: meter.global_avg for k, meter in metric_logger.meters.items()},auc_roc
+

main_finetune.py

@@ -0,0 +1,387 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+# --------------------------------------------------------
+# References:
+# DeiT: https://github.com/facebookresearch/deit
+# BEiT: https://github.com/microsoft/unilm/tree/master/beit
+# --------------------------------------------------------
+
+import argparse
+import datetime
+import json
+import numpy as np
+import os
+import time
+from pathlib import Path
+
+import torch
+import torch.backends.cudnn as cudnn
+from torch.utils.tensorboard import SummaryWriter
+
+import timm
+
+assert timm.__version__ == "0.3.2" # version check
+from timm.models.layers import trunc_normal_
+from timm.data.mixup import Mixup
+from timm.loss import LabelSmoothingCrossEntropy, SoftTargetCrossEntropy
+
+import util.lr_decay as lrd
+import util.misc as misc
+from util.datasets import build_dataset
+from util.pos_embed import interpolate_pos_embed
+from util.misc import NativeScalerWithGradNormCount as NativeScaler
+
+import models_vit
+
+from engine_finetune import train_one_epoch, evaluate
+
+
+def get_args_parser():
+    parser = argparse.ArgumentParser('MAE fine-tuning for image classification', add_help=False)
+    parser.add_argument('--batch_size', default=64, type=int,
+                        help='Batch size per GPU (effective batch size is batch_size * accum_iter * # gpus')
+    parser.add_argument('--epochs', default=50, type=int)
+    parser.add_argument('--accum_iter', default=1, type=int,
+                        help='Accumulate gradient iterations (for increasing the effective batch size under memory constraints)')
+
+    # Model parameters
+    parser.add_argument('--model', default='vit_large_patch16', type=str, metavar='MODEL',
+                        help='Name of model to train')
+
+    parser.add_argument('--input_size', default=224, type=int,
+                        help='images input size')
+
+    parser.add_argument('--drop_path', type=float, default=0.1, metavar='PCT',
+                        help='Drop path rate (default: 0.1)')
+
+    # Optimizer parameters
+    parser.add_argument('--clip_grad', type=float, default=None, metavar='NORM',
+                        help='Clip gradient norm (default: None, no clipping)')
+    parser.add_argument('--weight_decay', type=float, default=0.05,
+                        help='weight decay (default: 0.05)')
+
+    parser.add_argument('--lr', type=float, default=None, metavar='LR',
+                        help='learning rate (absolute lr)')
+    parser.add_argument('--blr', type=float, default=1e-3, metavar='LR',
+                        help='base learning rate: absolute_lr = base_lr * total_batch_size / 256')
+    parser.add_argument('--layer_decay', type=float, default=0.75,
+                        help='layer-wise lr decay from ELECTRA/BEiT')
+
+    parser.add_argument('--min_lr', type=float, default=1e-6, metavar='LR',
+                        help='lower lr bound for cyclic schedulers that hit 0')
+
+    parser.add_argument('--warmup_epochs', type=int, default=10, metavar='N',
+                        help='epochs to warmup LR')
+
+    # Augmentation parameters
+    parser.add_argument('--color_jitter', type=float, default=None, metavar='PCT',
+                        help='Color jitter factor (enabled only when not using Auto/RandAug)')
+    parser.add_argument('--aa', type=str, default='rand-m9-mstd0.5-inc1', metavar='NAME',
+                        help='Use AutoAugment policy. "v0" or "original". " + "(default: rand-m9-mstd0.5-inc1)'),
+    parser.add_argument('--smoothing', type=float, default=0.1,
+                        help='Label smoothing (default: 0.1)')
+
+    # * Random Erase params
+    parser.add_argument('--reprob', type=float, default=0.25, metavar='PCT',
+                        help='Random erase prob (default: 0.25)')
+    parser.add_argument('--remode', type=str, default='pixel',
+                        help='Random erase mode (default: "pixel")')
+    parser.add_argument('--recount', type=int, default=1,
+                        help='Random erase count (default: 1)')
+    parser.add_argument('--resplit', action='store_true', default=False,
+                        help='Do not random erase first (clean) augmentation split')
+
+    # * Mixup params
+    parser.add_argument('--mixup', type=float, default=0,
+                        help='mixup alpha, mixup enabled if > 0.')
+    parser.add_argument('--cutmix', type=float, default=0,
+                        help='cutmix alpha, cutmix enabled if > 0.')
+    parser.add_argument('--cutmix_minmax', type=float, nargs='+', default=None,
+                        help='cutmix min/max ratio, overrides alpha and enables cutmix if set (default: None)')
+    parser.add_argument('--mixup_prob', type=float, default=1.0,
+                        help='Probability of performing mixup or cutmix when either/both is enabled')
+    parser.add_argument('--mixup_switch_prob', type=float, default=0.5,
+                        help='Probability of switching to cutmix when both mixup and cutmix enabled')
+    parser.add_argument('--mixup_mode', type=str, default='batch',
+                        help='How to apply mixup/cutmix params. Per "batch", "pair", or "elem"')
+
+    # * Finetuning params
+    parser.add_argument('--finetune', default='',type=str,
+                        help='finetune from checkpoint')
+    parser.add_argument('--task', default='',type=str,
+                        help='finetune from checkpoint')
+    parser.add_argument('--global_pool', action='store_true')
+    parser.set_defaults(global_pool=True)
+    parser.add_argument('--cls_token', action='store_false', dest='global_pool',
+                        help='Use class token instead of global pool for classification')
+
+    # Dataset parameters
+    parser.add_argument('--data_path', default='/home/jupyter/Mor_DR_data/data/data/IDRID/Disease_Grading/', type=str,
+                        help='dataset path')
+    parser.add_argument('--nb_classes', default=1000, type=int,
+                        help='number of the classification types')
+
+    parser.add_argument('--output_dir', default='./output_dir',
+                        help='path where to save, empty for no saving')
+    parser.add_argument('--log_dir', default='./output_dir',
+                        help='path where to tensorboard log')
+    parser.add_argument('--device', default='cuda',
+                        help='device to use for training / testing')
+    parser.add_argument('--seed', default=0, type=int)
+    parser.add_argument('--resume', default='',
+                        help='resume from checkpoint')
+
+    parser.add_argument('--start_epoch', default=0, type=int, metavar='N',
+                        help='start epoch')
+    parser.add_argument('--eval', action='store_true',
+                        help='Perform evaluation only')
+    parser.add_argument('--dist_eval', action='store_true', default=False,
+                        help='Enabling distributed evaluation (recommended during training for faster monitor')
+    parser.add_argument('--num_workers', default=10, type=int)
+    parser.add_argument('--pin_mem', action='store_true',
+                        help='Pin CPU memory in DataLoader for more efficient (sometimes) transfer to GPU.')
+    parser.add_argument('--no_pin_mem', action='store_false', dest='pin_mem')
+    parser.set_defaults(pin_mem=True)
+
+    # distributed training parameters
+    parser.add_argument('--world_size', default=1, type=int,
+                        help='number of distributed processes')
+    parser.add_argument('--local_rank', default=-1, type=int)
+    parser.add_argument('--dist_on_itp', action='store_true')
+    parser.add_argument('--dist_url', default='env://',
+                        help='url used to set up distributed training')
+
+    return parser
+
+
+def main(args):
+    misc.init_distributed_mode(args)
+
+    print('job dir: {}'.format(os.path.dirname(os.path.realpath(__file__))))
+    print("{}".format(args).replace(', ', ',\n'))
+
+    device = torch.device(args.device)
+
+    # fix the seed for reproducibility
+    seed = args.seed + misc.get_rank()
+    torch.manual_seed(seed)
+    np.random.seed(seed)
+
+    cudnn.benchmark = True
+
+    dataset_train = build_dataset(is_train='train', args=args)
+    dataset_val = build_dataset(is_train='val', args=args)
+    dataset_test = build_dataset(is_train='test', args=args)
+
+    if True:  # args.distributed:
+        num_tasks = misc.get_world_size()
+        global_rank = misc.get_rank()
+        sampler_train = torch.utils.data.DistributedSampler(
+            dataset_train, num_replicas=num_tasks, rank=global_rank, shuffle=True
+        )
+        print("Sampler_train = %s" % str(sampler_train))
+        if args.dist_eval:
+            if len(dataset_val) % num_tasks != 0:
+                print('Warning: Enabling distributed evaluation with an eval dataset not divisible by process number. '
+                      'This will slightly alter validation results as extra duplicate entries are added to achieve '
+                      'equal num of samples per-process.')
+            sampler_val = torch.utils.data.DistributedSampler(
+                dataset_val, num_replicas=num_tasks, rank=global_rank, shuffle=True)  # shuffle=True to reduce monitor bias
+        else:
+            sampler_val = torch.utils.data.SequentialSampler(dataset_val)
+            
+        if args.dist_eval:
+            if len(dataset_test) % num_tasks != 0:
+                print('Warning: Enabling distributed evaluation with an eval dataset not divisible by process number. '
+                      'This will slightly alter validation results as extra duplicate entries are added to achieve '
+                      'equal num of samples per-process.')
+            sampler_test = torch.utils.data.DistributedSampler(
+                dataset_test, num_replicas=num_tasks, rank=global_rank, shuffle=True)  # shuffle=True to reduce monitor bias
+        else:
+            sampler_test = torch.utils.data.SequentialSampler(dataset_test)
+            
+            
+    else:
+        sampler_train = torch.utils.data.RandomSampler(dataset_train)
+        sampler_val = torch.utils.data.SequentialSampler(dataset_val)
+        sampler_test = torch.utils.data.SequentialSampler(dataset_test)
+
+    if global_rank == 0 and args.log_dir is not None and not args.eval:
+        os.makedirs(args.log_dir, exist_ok=True)
+        log_writer = SummaryWriter(log_dir=args.log_dir+args.task)
+    else:
+        log_writer = None
+
+    data_loader_train = torch.utils.data.DataLoader(
+        dataset_train, sampler=sampler_train,
+        batch_size=args.batch_size,
+        num_workers=args.num_workers,
+        pin_memory=args.pin_mem,
+        drop_last=True,
+    )
+
+    data_loader_val = torch.utils.data.DataLoader(
+        dataset_val, sampler=sampler_val,
+        batch_size=args.batch_size,
+        num_workers=args.num_workers,
+        pin_memory=args.pin_mem,
+        drop_last=False
+    )
+
+    data_loader_test = torch.utils.data.DataLoader(
+        dataset_test, sampler=sampler_test,
+        batch_size=args.batch_size,
+        num_workers=args.num_workers,
+        pin_memory=args.pin_mem,
+        drop_last=False
+    )
+    
+    
+    mixup_fn = None
+    mixup_active = args.mixup > 0 or args.cutmix > 0. or args.cutmix_minmax is not None
+    if mixup_active:
+        print("Mixup is activated!")
+        mixup_fn = Mixup(
+            mixup_alpha=args.mixup, cutmix_alpha=args.cutmix, cutmix_minmax=args.cutmix_minmax,
+            prob=args.mixup_prob, switch_prob=args.mixup_switch_prob, mode=args.mixup_mode,
+            label_smoothing=args.smoothing, num_classes=args.nb_classes)
+    
+    model = models_vit.__dict__[args.model](
+        num_classes=args.nb_classes,
+        drop_path_rate=args.drop_path,
+        global_pool=args.global_pool,
+    )
+
+    if args.finetune and not args.eval:
+        checkpoint = torch.load(args.finetune, map_location='cpu')
+
+        print("Load pre-trained checkpoint from: %s" % args.finetune)
+        checkpoint_model = checkpoint['model']
+        state_dict = model.state_dict()
+        for k in ['head.weight', 'head.bias']:
+            if k in checkpoint_model and checkpoint_model[k].shape != state_dict[k].shape:
+                print(f"Removing key {k} from pretrained checkpoint")
+                del checkpoint_model[k]
+
+        # interpolate position embedding
+        interpolate_pos_embed(model, checkpoint_model)
+
+        # load pre-trained model
+        msg = model.load_state_dict(checkpoint_model, strict=False)
+        print(msg)
+
+        if args.global_pool:
+            assert set(msg.missing_keys) == {'head.weight', 'head.bias', 'fc_norm.weight', 'fc_norm.bias'}
+        else:
+            assert set(msg.missing_keys) == {'head.weight', 'head.bias'}
+
+        # manually initialize fc layer
+        trunc_normal_(model.head.weight, std=2e-5)
+
+    model.to(device)
+
+    model_without_ddp = model
+    n_parameters = sum(p.numel() for p in model.parameters() if p.requires_grad)
+
+    print("Model = %s" % str(model_without_ddp))
+    print('number of params (M): %.2f' % (n_parameters / 1.e6))
+
+    eff_batch_size = args.batch_size * args.accum_iter * misc.get_world_size()
+    
+    if args.lr is None:  # only base_lr is specified
+        args.lr = args.blr * eff_batch_size / 256
+
+    print("base lr: %.2e" % (args.lr * 256 / eff_batch_size))
+    print("actual lr: %.2e" % args.lr)
+
+    print("accumulate grad iterations: %d" % args.accum_iter)
+    print("effective batch size: %d" % eff_batch_size)
+
+    if args.distributed:
+        model = torch.nn.parallel.DistributedDataParallel(model, device_ids=[args.gpu])
+        model_without_ddp = model.module
+
+    # build optimizer with layer-wise lr decay (lrd)
+    param_groups = lrd.param_groups_lrd(model_without_ddp, args.weight_decay,
+        no_weight_decay_list=model_without_ddp.no_weight_decay(),
+        layer_decay=args.layer_decay
+    )
+    optimizer = torch.optim.AdamW(param_groups, lr=args.lr)
+    loss_scaler = NativeScaler()
+
+    if mixup_fn is not None:
+        # smoothing is handled with mixup label transform
+        criterion = SoftTargetCrossEntropy()
+    elif args.smoothing > 0.:
+        criterion = LabelSmoothingCrossEntropy(smoothing=args.smoothing)
+    else:
+        criterion = torch.nn.CrossEntropyLoss()
+
+    print("criterion = %s" % str(criterion))
+
+    misc.load_model(args=args, model_without_ddp=model_without_ddp, optimizer=optimizer, loss_scaler=loss_scaler)
+
+    if args.eval:
+        test_stats,auc_roc = evaluate(data_loader_test, model, device, args.task, epoch=0, mode='test',num_class=args.nb_classes)
+        exit(0)
+
+    print(f"Start training for {args.epochs} epochs")
+    start_time = time.time()
+    max_accuracy = 0.0
+    max_auc = 0.0
+    for epoch in range(args.start_epoch, args.epochs):
+        if args.distributed:
+            data_loader_train.sampler.set_epoch(epoch)
+        train_stats = train_one_epoch(
+            model, criterion, data_loader_train,
+            optimizer, device, epoch, loss_scaler,
+            args.clip_grad, mixup_fn,
+            log_writer=log_writer,
+            args=args
+        )
+
+        val_stats,val_auc_roc = evaluate(data_loader_val, model, device,args.task,epoch, mode='val',num_class=args.nb_classes)
+        if max_auc<val_auc_roc:
+            max_auc = val_auc_roc
+            
+            if args.output_dir:
+                misc.save_model(
+                    args=args, model=model, model_without_ddp=model_without_ddp, optimizer=optimizer,
+                    loss_scaler=loss_scaler, epoch=epoch)
+        
+
+        if epoch==(args.epochs-1):
+            test_stats,auc_roc = evaluate(data_loader_test, model, device,args.task,epoch, mode='test',num_class=args.nb_classes)
+
+        
+        if log_writer is not None:
+            log_writer.add_scalar('perf/val_acc1', val_stats['acc1'], epoch)
+            log_writer.add_scalar('perf/val_auc', val_auc_roc, epoch)
+            log_writer.add_scalar('perf/val_loss', val_stats['loss'], epoch)
+            
+        log_stats = {**{f'train_{k}': v for k, v in train_stats.items()},
+                        'epoch': epoch,
+                        'n_parameters': n_parameters}
+
+        if args.output_dir and misc.is_main_process():
+            if log_writer is not None:
+                log_writer.flush()
+            with open(os.path.join(args.output_dir, "log.txt"), mode="a", encoding="utf-8") as f:
+                f.write(json.dumps(log_stats) + "\n")
+
+                
+    total_time = time.time() - start_time
+    total_time_str = str(datetime.timedelta(seconds=int(total_time)))
+    print('Training time {}'.format(total_time_str))
+
+
+if __name__ == '__main__':
+    args = get_args_parser()
+    args = args.parse_args()
+
+    if args.output_dir:
+        Path(args.output_dir).mkdir(parents=True, exist_ok=True)
+    main(args)

models_vit.py

@@ -0,0 +1,61 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+# --------------------------------------------------------
+# References:
+# timm: https://github.com/rwightman/pytorch-image-models/tree/master/timm
+# DeiT: https://github.com/facebookresearch/deit
+# --------------------------------------------------------
+
+from functools import partial
+
+import torch
+import torch.nn as nn
+
+import timm.models.vision_transformer
+
+
+class VisionTransformer(timm.models.vision_transformer.VisionTransformer):
+    """ Vision Transformer with support for global average pooling
+    """
+    def __init__(self, global_pool=False, **kwargs):
+        super(VisionTransformer, self).__init__(**kwargs)
+
+        self.global_pool = global_pool
+        if self.global_pool:
+            norm_layer = kwargs['norm_layer']
+            embed_dim = kwargs['embed_dim']
+            self.fc_norm = norm_layer(embed_dim)
+
+            del self.norm  # remove the original norm
+
+    def forward_features(self, x):
+        B = x.shape[0]
+        x = self.patch_embed(x)
+
+        cls_tokens = self.cls_token.expand(B, -1, -1)  # stole cls_tokens impl from Phil Wang, thanks
+        x = torch.cat((cls_tokens, x), dim=1)
+        x = x + self.pos_embed
+        x = self.pos_drop(x)
+
+        for blk in self.blocks:
+            x = blk(x)
+
+        if self.global_pool:
+            x = x[:, 1:, :].mean(dim=1)  # global pool without cls token
+            outcome = self.fc_norm(x)
+        else:
+            x = self.norm(x)
+            outcome = x[:, 0]
+
+        return outcome
+
+
+def vit_large_patch16(**kwargs):
+    model = VisionTransformer(
+        img_size=224,patch_size=16, embed_dim=1024, depth=24, num_heads=16, mlp_ratio=4, qkv_bias=True,
+        norm_layer=partial(nn.LayerNorm, eps=1e-6), **kwargs)
+    return model
+

requirement.txt

@@ -0,0 +1,53 @@
+absl-py==0.13.0
+art==5.2
+cached-property==1.5.2
+cachetools==4.2.2
+charset-normalizer==2.0.4
+cycler==0.10.0
+dataclasses==0.8
+decorator==4.4.2
+future==0.18.2
+google-auth==1.35.0
+google-auth-oauthlib==0.4.5
+grpcio==1.39.0
+h5py==3.1.0
+idna==3.2
+imageio==2.9.0
+importlib-metadata==4.6.4
+joblib==1.0.1
+kiwisolver==1.3.1
+Markdown==3.3.4
+matplotlib==3.3.4
+networkx==2.5.1
+numpy==1.19.5
+oauthlib==3.1.1
+opencv-python==4.5.3.56
+pandas==0.25.3
+Pillow==8.3.1
+protobuf==3.17.3
+pyasn1==0.4.8
+pyasn1-modules==0.2.8
+pycm==3.2
+pydicom==2.3.0
+pyparsing==2.4.7
+python-dateutil==2.8.2
+pytz==2021.1
+PyWavelets==1.1.1
+requests==2.26.0
+requests-oauthlib==1.3.0
+rsa==4.7.2
+scikit-image==0.17.2
+scikit-learn==0.24.2
+scipy==1.5.4
+six==1.16.0
+tensorboard==2.6.0
+tensorboard-data-server==0.6.1
+tensorboard-plugin-wit==1.8.0
+threadpoolctl==2.2.0
+tifffile==2020.9.3
+timm==0.3.2
+tqdm==4.62.1
+typing-extensions==3.10.0.0
+urllib3==1.26.6
+Werkzeug==2.0.1
+zipp==3.5.0

util/datasets.py

@@ -0,0 +1,60 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+# --------------------------------------------------------
+# References:
+# DeiT: https://github.com/facebookresearch/deit
+# --------------------------------------------------------
+
+import os
+import PIL
+from torchvision import datasets, transforms
+from timm.data import create_transform
+from timm.data.constants import IMAGENET_DEFAULT_MEAN, IMAGENET_DEFAULT_STD
+
+
+def build_dataset(is_train, args):
+    
+    transform = build_transform(is_train, args)
+    root = os.path.join(args.data_path, is_train)
+    dataset = datasets.ImageFolder(root, transform=transform)
+
+    return dataset
+
+
+def build_transform(is_train, args):
+    mean = IMAGENET_DEFAULT_MEAN
+    std = IMAGENET_DEFAULT_STD
+    # train transform
+    if is_train=='train':
+        # this should always dispatch to transforms_imagenet_train
+        transform = create_transform(
+            input_size=args.input_size,
+            is_training=True,
+            color_jitter=args.color_jitter,
+            auto_augment=args.aa,
+            interpolation='bicubic',
+            re_prob=args.reprob,
+            re_mode=args.remode,
+            re_count=args.recount,
+            mean=mean,
+            std=std,
+        )
+        return transform
+
+    # eval transform
+    t = []
+    if args.input_size <= 224:
+        crop_pct = 224 / 256
+    else:
+        crop_pct = 1.0
+    size = int(args.input_size / crop_pct)
+    t.append(
+        transforms.Resize(size, interpolation=transforms.InterpolationMode.BICUBIC), 
+    )
+    t.append(transforms.CenterCrop(args.input_size))
+    t.append(transforms.ToTensor())
+    t.append(transforms.Normalize(mean, std))
+    return transforms.Compose(t)

util/lr_decay.py

@@ -0,0 +1,76 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+# --------------------------------------------------------
+# References:
+# ELECTRA https://github.com/google-research/electra
+# BEiT: https://github.com/microsoft/unilm/tree/master/beit
+# --------------------------------------------------------
+
+import json
+
+
+def param_groups_lrd(model, weight_decay=0.05, no_weight_decay_list=[], layer_decay=.75):
+    """
+    Parameter groups for layer-wise lr decay
+    Following BEiT: https://github.com/microsoft/unilm/blob/master/beit/optim_factory.py#L58
+    """
+    param_group_names = {}
+    param_groups = {}
+
+    num_layers = len(model.blocks) + 1
+
+    layer_scales = list(layer_decay ** (num_layers - i) for i in range(num_layers + 1))
+
+    for n, p in model.named_parameters():
+        if not p.requires_grad:
+            continue
+
+        # no decay: all 1D parameters and model specific ones
+        if p.ndim == 1 or n in no_weight_decay_list:
+            g_decay = "no_decay"
+            this_decay = 0.
+        else:
+            g_decay = "decay"
+            this_decay = weight_decay
+            
+        layer_id = get_layer_id_for_vit(n, num_layers)
+        group_name = "layer_%d_%s" % (layer_id, g_decay)
+
+        if group_name not in param_group_names:
+            this_scale = layer_scales[layer_id]
+
+            param_group_names[group_name] = {
+                "lr_scale": this_scale,
+                "weight_decay": this_decay,
+                "params": [],
+            }
+            param_groups[group_name] = {
+                "lr_scale": this_scale,
+                "weight_decay": this_decay,
+                "params": [],
+            }
+
+        param_group_names[group_name]["params"].append(n)
+        param_groups[group_name]["params"].append(p)
+
+    # print("parameter groups: \n%s" % json.dumps(param_group_names, indent=2))
+
+    return list(param_groups.values())
+
+
+def get_layer_id_for_vit(name, num_layers):
+    """
+    Assign a parameter with its layer id
+    Following BEiT: https://github.com/microsoft/unilm/blob/master/beit/optim_factory.py#L33
+    """
+    if name in ['cls_token', 'pos_embed']:
+        return 0
+    elif name.startswith('patch_embed'):
+        return 0
+    elif name.startswith('blocks'):
+        return int(name.split('.')[1]) + 1
+    else:
+        return num_layers

util/lr_sched.py

@@ -0,0 +1,21 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+
+import math
+
+def adjust_learning_rate(optimizer, epoch, args):
+    """Decay the learning rate with half-cycle cosine after warmup"""
+    if epoch < args.warmup_epochs:
+        lr = args.lr * epoch / args.warmup_epochs 
+    else:
+        lr = args.min_lr + (args.lr - args.min_lr) * 0.5 * \
+            (1. + math.cos(math.pi * (epoch - args.warmup_epochs) / (args.epochs - args.warmup_epochs)))
+    for param_group in optimizer.param_groups:
+        if "lr_scale" in param_group:
+            param_group["lr"] = lr * param_group["lr_scale"]
+        else:
+            param_group["lr"] = lr
+    return lr

util/misc.py

@@ -0,0 +1,341 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+# --------------------------------------------------------
+# References:
+# DeiT: https://github.com/facebookresearch/deit
+# BEiT: https://github.com/microsoft/unilm/tree/master/beit
+# --------------------------------------------------------
+
+import builtins
+import datetime
+import os
+import time
+from collections import defaultdict, deque
+from pathlib import Path
+
+import torch
+import torch.distributed as dist
+from torch._six import inf
+
+
+class SmoothedValue(object):
+    """Track a series of values and provide access to smoothed values over a
+    window or the global series average.
+    """
+
+    def __init__(self, window_size=20, fmt=None):
+        if fmt is None:
+            fmt = "{median:.4f} ({global_avg:.4f})"
+        self.deque = deque(maxlen=window_size)
+        self.total = 0.0
+        self.count = 0
+        self.fmt = fmt
+
+    def update(self, value, n=1):
+        self.deque.append(value)
+        self.count += n
+        self.total += value * n
+
+    def synchronize_between_processes(self):
+        """
+        Warning: does not synchronize the deque!
+        """
+        if not is_dist_avail_and_initialized():
+            return
+        t = torch.tensor([self.count, self.total], dtype=torch.float64, device='cuda')
+        dist.barrier()
+        dist.all_reduce(t)
+        t = t.tolist()
+        self.count = int(t[0])
+        self.total = t[1]
+
+    @property
+    def median(self):
+        d = torch.tensor(list(self.deque))
+        return d.median().item()
+
+    @property
+    def avg(self):
+        d = torch.tensor(list(self.deque), dtype=torch.float32)
+        return d.mean().item()
+
+    @property
+    def global_avg(self):
+        return self.total / self.count
+
+    @property
+    def max(self):
+        return max(self.deque)
+
+    @property
+    def value(self):
+        return self.deque[-1]
+
+    def __str__(self):
+        return self.fmt.format(
+            median=self.median,
+            avg=self.avg,
+            global_avg=self.global_avg,
+            max=self.max,
+            value=self.value)
+
+
+class MetricLogger(object):
+    def __init__(self, delimiter="\t"):
+        self.meters = defaultdict(SmoothedValue)
+        self.delimiter = delimiter
+
+    def update(self, **kwargs):
+        for k, v in kwargs.items():
+            if v is None:
+                continue
+            if isinstance(v, torch.Tensor):
+                v = v.item()
+            assert isinstance(v, (float, int))
+            self.meters[k].update(v)
+
+    def __getattr__(self, attr):
+        if attr in self.meters:
+            return self.meters[attr]
+        if attr in self.__dict__:
+            return self.__dict__[attr]
+        raise AttributeError("'{}' object has no attribute '{}'".format(
+            type(self).__name__, attr))
+
+    def __str__(self):
+        loss_str = []
+        for name, meter in self.meters.items():
+            loss_str.append(
+                "{}: {}".format(name, str(meter))
+            )
+        return self.delimiter.join(loss_str)
+
+    def synchronize_between_processes(self):
+        for meter in self.meters.values():
+            meter.synchronize_between_processes()
+
+    def add_meter(self, name, meter):
+        self.meters[name] = meter
+
+    def log_every(self, iterable, print_freq, header=None):
+        i = 0
+        if not header:
+            header = ''
+        start_time = time.time()
+        end = time.time()
+        iter_time = SmoothedValue(fmt='{avg:.4f}')
+        data_time = SmoothedValue(fmt='{avg:.4f}')
+        space_fmt = ':' + str(len(str(len(iterable)))) + 'd'
+        log_msg = [
+            header,
+            '[{0' + space_fmt + '}/{1}]',
+            'eta: {eta}',
+            '{meters}',
+            'time: {time}',
+            'data: {data}'
+        ]
+        if torch.cuda.is_available():
+            log_msg.append('max mem: {memory:.0f}')
+        log_msg = self.delimiter.join(log_msg)
+        MB = 1024.0 * 1024.0
+        for obj in iterable:
+            data_time.update(time.time() - end)
+            yield obj
+            iter_time.update(time.time() - end)
+            if i % print_freq == 0 or i == len(iterable) - 1:
+                eta_seconds = iter_time.global_avg * (len(iterable) - i)
+                eta_string = str(datetime.timedelta(seconds=int(eta_seconds)))
+                if torch.cuda.is_available():
+                    print(log_msg.format(
+                        i, len(iterable), eta=eta_string,
+                        meters=str(self),
+                        time=str(iter_time), data=str(data_time),
+                        memory=torch.cuda.max_memory_allocated() / MB))
+                else:
+                    print(log_msg.format(
+                        i, len(iterable), eta=eta_string,
+                        meters=str(self),
+                        time=str(iter_time), data=str(data_time)))
+            i += 1
+            end = time.time()
+        total_time = time.time() - start_time
+        total_time_str = str(datetime.timedelta(seconds=int(total_time)))
+        print('{} Total time: {} ({:.4f} s / it)'.format(
+            header, total_time_str, total_time / len(iterable)))
+
+
+def setup_for_distributed(is_master):
+    """
+    This function disables printing when not in master process
+    """
+    builtin_print = builtins.print
+
+    def print(*args, **kwargs):
+        force = kwargs.pop('force', False)
+        force = force or (get_world_size() > 8)
+        if is_master or force:
+            now = datetime.datetime.now().time()
+            builtin_print('[{}] '.format(now), end='')  # print with time stamp
+            builtin_print(*args, **kwargs)
+
+    builtins.print = print
+
+
+def is_dist_avail_and_initialized():
+    if not dist.is_available():
+        return False
+    if not dist.is_initialized():
+        return False
+    return True
+
+
+def get_world_size():
+    if not is_dist_avail_and_initialized():
+        return 1
+    return dist.get_world_size()
+
+
+def get_rank():
+    if not is_dist_avail_and_initialized():
+        return 0
+    return dist.get_rank()
+
+
+def is_main_process():
+    return get_rank() == 0
+
+
+def save_on_master(*args, **kwargs):
+    if is_main_process():
+        torch.save(*args, **kwargs)
+
+
+def init_distributed_mode(args):
+    if args.dist_on_itp:
+        args.rank = int(os.environ['OMPI_COMM_WORLD_RANK'])
+        args.world_size = int(os.environ['OMPI_COMM_WORLD_SIZE'])
+        args.gpu = int(os.environ['OMPI_COMM_WORLD_LOCAL_RANK'])
+        args.dist_url = "tcp://%s:%s" % (os.environ['MASTER_ADDR'], os.environ['MASTER_PORT'])
+        os.environ['LOCAL_RANK'] = str(args.gpu)
+        os.environ['RANK'] = str(args.rank)
+        os.environ['WORLD_SIZE'] = str(args.world_size)
+        # ["RANK", "WORLD_SIZE", "MASTER_ADDR", "MASTER_PORT", "LOCAL_RANK"]
+    elif 'RANK' in os.environ and 'WORLD_SIZE' in os.environ:
+        args.rank = int(os.environ["RANK"])
+        args.world_size = int(os.environ['WORLD_SIZE'])
+        args.gpu = int(os.environ['LOCAL_RANK'])
+    elif 'SLURM_PROCID' in os.environ:
+        args.rank = int(os.environ['SLURM_PROCID'])
+        args.gpu = args.rank % torch.cuda.device_count()
+    else:
+        print('Not using distributed mode')
+        setup_for_distributed(is_master=True)  # hack
+        args.distributed = False
+        return
+
+    args.distributed = True
+
+    torch.cuda.set_device(args.gpu)
+    args.dist_backend = 'nccl'
+    print('| distributed init (rank {}): {}, gpu {}'.format(
+        args.rank, args.dist_url, args.gpu), flush=True)
+    torch.distributed.init_process_group(backend=args.dist_backend, init_method=args.dist_url,
+                                         world_size=args.world_size, rank=args.rank)
+    torch.distributed.barrier()
+    setup_for_distributed(args.rank == 0)
+
+
+class NativeScalerWithGradNormCount:
+    state_dict_key = "amp_scaler"
+
+    def __init__(self):
+        self._scaler = torch.cuda.amp.GradScaler()
+
+    def __call__(self, loss, optimizer, clip_grad=None, parameters=None, create_graph=False, update_grad=True):
+        self._scaler.scale(loss).backward(create_graph=create_graph)
+        if update_grad:
+            if clip_grad is not None:
+                assert parameters is not None
+                self._scaler.unscale_(optimizer)  # unscale the gradients of optimizer's assigned params in-place
+                norm = torch.nn.utils.clip_grad_norm_(parameters, clip_grad)
+            else:
+                self._scaler.unscale_(optimizer)
+                norm = get_grad_norm_(parameters)
+            self._scaler.step(optimizer)
+            self._scaler.update()
+        else:
+            norm = None
+        return norm
+
+    def state_dict(self):
+        return self._scaler.state_dict()
+
+    def load_state_dict(self, state_dict):
+        self._scaler.load_state_dict(state_dict)
+
+
+def get_grad_norm_(parameters, norm_type: float = 2.0) -> torch.Tensor:
+    if isinstance(parameters, torch.Tensor):
+        parameters = [parameters]
+    parameters = [p for p in parameters if p.grad is not None]
+    norm_type = float(norm_type)
+    if len(parameters) == 0:
+        return torch.tensor(0.)
+    device = parameters[0].grad.device
+    if norm_type == inf:
+        total_norm = max(p.grad.detach().abs().max().to(device) for p in parameters)
+    else:
+        total_norm = torch.norm(torch.stack([torch.norm(p.grad.detach(), norm_type).to(device) for p in parameters]), norm_type)
+    return total_norm
+
+
+def save_model(args, epoch, model, model_without_ddp, optimizer, loss_scaler):
+    output_dir = Path(args.output_dir)
+    epoch_name = str(epoch)
+    if loss_scaler is not None:
+        checkpoint_paths = [args.task+'checkpoint-best.pth']
+        for checkpoint_path in checkpoint_paths:
+            to_save = {
+                'model': model_without_ddp.state_dict(),
+                'optimizer': optimizer.state_dict(),
+                'epoch': epoch,
+                'scaler': loss_scaler.state_dict(),
+                'args': args,
+            }
+
+            save_on_master(to_save, checkpoint_path)
+    else:
+        client_state = {'epoch': epoch}
+        model.save_checkpoint(save_dir=args.task, tag="checkpoint-best", client_state=client_state)
+
+
+def load_model(args, model_without_ddp, optimizer, loss_scaler):
+    if args.resume:
+        if args.resume.startswith('https'):
+            checkpoint = torch.hub.load_state_dict_from_url(
+                args.resume, map_location='cpu', check_hash=True)
+        else:
+            checkpoint = torch.load(args.resume, map_location='cpu')
+        model_without_ddp.load_state_dict(checkpoint['model'])
+        print("Resume checkpoint %s" % args.resume)
+        if 'optimizer' in checkpoint and 'epoch' in checkpoint and not (hasattr(args, 'eval') and args.eval):
+            optimizer.load_state_dict(checkpoint['optimizer'])
+            args.start_epoch = checkpoint['epoch'] + 1
+            if 'scaler' in checkpoint:
+                loss_scaler.load_state_dict(checkpoint['scaler'])
+            print("With optim & sched!")
+
+
+def all_reduce_mean(x):
+    world_size = get_world_size()
+    if world_size > 1:
+        x_reduce = torch.tensor(x).cuda()
+        dist.all_reduce(x_reduce)
+        x_reduce /= world_size
+        return x_reduce.item()
+    else:
+        return x
+    

util/pos_embed.py

@@ -0,0 +1,96 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+
+# This source code is licensed under the license found in the
+# LICENSE file in the root directory of this source tree.
+# --------------------------------------------------------
+# Position embedding utils
+# --------------------------------------------------------
+
+import numpy as np
+
+import torch
+
+# --------------------------------------------------------
+# 2D sine-cosine position embedding
+# References:
+# Transformer: https://github.com/tensorflow/models/blob/master/official/nlp/transformer/model_utils.py
+# MoCo v3: https://github.com/facebookresearch/moco-v3
+# --------------------------------------------------------
+def get_2d_sincos_pos_embed(embed_dim, grid_size, cls_token=False):
+    """
+    grid_size: int of the grid height and width
+    return:
+    pos_embed: [grid_size*grid_size, embed_dim] or [1+grid_size*grid_size, embed_dim] (w/ or w/o cls_token)
+    """
+    grid_h = np.arange(grid_size, dtype=np.float32)
+    grid_w = np.arange(grid_size, dtype=np.float32)
+    grid = np.meshgrid(grid_w, grid_h)  # here w goes first
+    grid = np.stack(grid, axis=0)
+
+    grid = grid.reshape([2, 1, grid_size, grid_size])
+    pos_embed = get_2d_sincos_pos_embed_from_grid(embed_dim, grid)
+    if cls_token:
+        pos_embed = np.concatenate([np.zeros([1, embed_dim]), pos_embed], axis=0)
+    return pos_embed
+
+
+def get_2d_sincos_pos_embed_from_grid(embed_dim, grid):
+    assert embed_dim % 2 == 0
+
+    # use half of dimensions to encode grid_h
+    emb_h = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[0])  # (H*W, D/2)
+    emb_w = get_1d_sincos_pos_embed_from_grid(embed_dim // 2, grid[1])  # (H*W, D/2)
+
+    emb = np.concatenate([emb_h, emb_w], axis=1) # (H*W, D)
+    return emb
+
+
+def get_1d_sincos_pos_embed_from_grid(embed_dim, pos):
+    """
+    embed_dim: output dimension for each position
+    pos: a list of positions to be encoded: size (M,)
+    out: (M, D)
+    """
+    assert embed_dim % 2 == 0
+    omega = np.arange(embed_dim // 2, dtype=np.float)
+    omega /= embed_dim / 2.
+    omega = 1. / 10000**omega  # (D/2,)
+
+    pos = pos.reshape(-1)  # (M,)
+    out = np.einsum('m,d->md', pos, omega)  # (M, D/2), outer product
+
+    emb_sin = np.sin(out) # (M, D/2)
+    emb_cos = np.cos(out) # (M, D/2)
+
+    emb = np.concatenate([emb_sin, emb_cos], axis=1)  # (M, D)
+    return emb
+
+
+# --------------------------------------------------------
+# Interpolate position embeddings for high-resolution
+# References:
+# DeiT: https://github.com/facebookresearch/deit
+# --------------------------------------------------------
+def interpolate_pos_embed(model, checkpoint_model):
+    if 'pos_embed' in checkpoint_model:
+        pos_embed_checkpoint = checkpoint_model['pos_embed']
+        embedding_size = pos_embed_checkpoint.shape[-1]
+        num_patches = model.patch_embed.num_patches
+        num_extra_tokens = model.pos_embed.shape[-2] - num_patches
+        # height (== width) for the checkpoint position embedding
+        orig_size = int((pos_embed_checkpoint.shape[-2] - num_extra_tokens) ** 0.5)
+        # height (== width) for the new position embedding
+        new_size = int(num_patches ** 0.5)
+        # class_token and dist_token are kept unchanged
+        if orig_size != new_size:
+            print("Position interpolate from %dx%d to %dx%d" % (orig_size, orig_size, new_size, new_size))
+            extra_tokens = pos_embed_checkpoint[:, :num_extra_tokens]
+            # only the position tokens are interpolated
+            pos_tokens = pos_embed_checkpoint[:, num_extra_tokens:]
+            pos_tokens = pos_tokens.reshape(-1, orig_size, orig_size, embedding_size).permute(0, 3, 1, 2)
+            pos_tokens = torch.nn.functional.interpolate(
+                pos_tokens, size=(new_size, new_size), mode='bicubic', align_corners=False)
+            pos_tokens = pos_tokens.permute(0, 2, 3, 1).flatten(1, 2)
+            new_pos_embed = torch.cat((extra_tokens, pos_tokens), dim=1)
+            checkpoint_model['pos_embed'] = new_pos_embed