feat: add ssd detector (mindspore-lab#704)

examples/det/ssd/README.md

@@ -0,0 +1,143 @@
+# SSD Based on MindCV Backbones
+
+> [SSD: Single Shot MultiBox Detector](https://arxiv.org/abs/1512.02325)
+
+## Introduction
+
+SSD is an single-staged object detector. It discretizes the output space of bounding boxes into a set of default boxes over different aspect ratios and scales per feature map location, and combines predictions from multi-scale feature maps to detect objects with various sizes. At prediction time, SSD generates scores for the presence of each object category in each default box and produces adjustments to the box to better match the object shape.
+
+<p align="center">
+  <img src="https://github.com/DexterJZ/mindcv/assets/16130861/50bc9627-c71c-4b1a-9de4-9e6040a43279" width=800 />
+</p>
+<p align="center">
+  <em>Figure 1. Architecture of SSD [<a href="#references">1</a>] </em>
+</p>
+
+In this example, by leveraging [the multi-scale feature extraction of MindCV](https://github.com/mindspore-lab/mindcv/blob/main/docs/en/how_to_guides/feature_extraction.md), we demonstrate that using backbones from MindCV much simplifies the implementation of SSD.
+
+## Configurations
+
+Here, we provide three configurations of SSD.
+* Using [MobileNetV2](https://github.com/mindspore-lab/mindcv/tree/main/configs/mobilenetv2) as the backbone and the original detector described in the paper.
+* Using [ResNet50](https://github.com/mindspore-lab/mindcv/tree/main/configs/resnet) as the backbone with a FPN and a shared-weight-based detector.
+* Using [MobileNetV3](https://github.com/mindspore-lab/mindcv/tree/main/configs/mobilenetv3) as the backbone and the original detector described in the paper.
+
+## Dataset
+
+We train and test SSD using [COCO 2017 Dataset](https://cocodataset.org/#download). The dataset contains
+* 118000 images about 18 GB for training, and
+* 5000 images about 1 GB for testing.
+
+## Quick Start
+
+### Preparation
+
+1. Clone MindCV repository by running
+```
+git clone https://github.com/mindspore-lab/mindcv.git
+```
+
+2. Install dependencies as shown [here](https://mindspore-lab.github.io/mindcv/installation/).
+
+3. Download [COCO 2017 Dataset](https://cocodataset.org/#download), prepare the dataset as follows.
+```
+.
+└─cocodataset
+  ├─annotations
+    ├─instance_train2017.json
+    └─instance_val2017.json
+  ├─val2017
+  └─train2017
+```
+Run the following commands to preprocess the dataset and convert it to [MindRecord format](https://www.mindspore.cn/docs/zh-CN/master/api_python/mindspore.mindrecord.html) for reducing preprocessing time during training and testing.
+```
+cd mindcv  # change directory to the root of MindCV repository
+python examples/det/ssd/create_data.py coco --data_path [root of COCO 2017 Dataset] --out_path [directory for storing MindRecord files]
+```
+Specify the path of the preprocessed dataset at keyword `data_dir` in the config file.
+
+4. Download the pretrained backbone weights from the table below, and specify the path to the backbone weights at keyword `backbone_ckpt_path` in the config file.
+<div align="center">
+
+|    MobileNetV2   |     ResNet50     |    MobileNetV3   |
+|:----------------:|:----------------:|:----------------:|
+| [backbone weights](https://download.mindspore.cn/toolkits/mindcv/mobilenet/mobilenetv2/mobilenet_v2_100-d5532038.ckpt) | [backbone weights](https://download.mindspore.cn/toolkits/mindcv/resnet/resnet50-e0733ab8.ckpt) | [backbone weights](https://download.mindspore.cn/toolkits/mindcv/mobilenet/mobilenetv3/mobilenet_v3_large_100-1279ad5f.ckpt) |
+
+</div>
+
+### Train
+
+It is highly recommended to use **distributed training** for this SSD implementation.
+
+For distributed training using **OpenMPI's `mpirun`**, simply run
+```
+cd mindcv  # change directory to the root of MindCV repository
+mpirun -n [# of devices] python examples/det/ssd/train.py --config [the path to the config file]
+```
+For example, if train SSD distributively with the `MobileNetV2` configuration on 8 devices, run
+```
+cd mindcv  # change directory to the root of MindCV repository
+mpirun -n 8 python examples/det/ssd/train.py --config examples/det/ssd/ssd_mobilenetv2.yaml
+```
+
+For distributed training with [Ascend rank table](https://github.com/mindspore-lab/mindocr/blob/main/docs/en/tutorials/distribute_train.md#12-configure-rank_table_file-for-training), configure `ascend8p.sh` as follows
+```
+#!/bin/bash
+export DEVICE_NUM=8
+export RANK_SIZE=8
+export RANK_TABLE_FILE="./hccl_8p_01234567_127.0.0.1.json"
+
+for ((i = 0; i < ${DEVICE_NUM}; i++)); do
+    export DEVICE_ID=$i
+    export RANK_ID=$i
+    echo "Launching rank: ${RANK_ID}, device: ${DEVICE_ID}"
+    if [ $i -eq 0 ]; then
+      echo 'i am 0'
+      python examples/det/ssd/train.py --config [the path to the config file] &> ./train.log &
+    else
+      echo 'not 0'
+      python -u examples/det/ssd/train.py --config [the path to the config file] &> /dev/null &
+    fi
+done
+```
+and start training by running
+```
+cd mindcv  # change directory to the root of MindCV repository
+bash ascend8p.sh
+```
+
+For single-device training, please run
+```
+cd mindcv  # change directory to the root of MindCV repository
+python examples/det/ssd/train.py --config [the path to the config file]
+```
+
+### Test
+
+For testing the trained model, first specify the path to the model checkpoint at keyword `ckpt_path` in the config file, then run
+```
+cd mindcv  # change directory to the root of MindCV repository
+python examples/det/ssd/eval.py --config [the path to the config file]
+```
+For example, for testing SSD with the `MobileNetV2` configuration, run
+```
+cd mindcv  # change directory to the root of MindCV repository
+python examples/det/ssd/eval.py --config examples/det/ssd/ssd_mobilenetv2.yaml
+```
+
+## Performance
+
+Here are the performance resutls and the pretrained model weights for each configuration.
+<div align="center">
+
+|   Configuration   | Mixed Precision |  mAP | Config | Download |
+|:-----------------:|:---------------:|:----:|:------:|:--------:|
+|    MobileNetV2    |        O2       | 23.2 |  [yaml](https://github.com/mindspore-lab/mindcv/blob/main/examples/det/ssd/ssd_mobilenetv2.yaml)  |  [weights](https://download.mindspore.cn/toolkits/mindcv/ssd/ssd_mobilenetv2-5bbd7411.ckpt) |
+| ResNet50 with FPN |        O3       | 38.3 |  [yaml](https://github.com/mindspore-lab/mindcv/blob/main/examples/det/ssd/ssd_resnet50_fpn.yaml)  |  [weights](https://download.mindspore.cn/toolkits/mindcv/ssd/ssd_resnet50_fpn-ac87ddac.ckpt) |
+|    MobileNetV3    |        O2       | 23.8 |  [yaml](https://github.com/mindspore-lab/mindcv/blob/main/examples/det/ssd/ssd_mobilenetv3.yaml)  |  [weights](https://download.mindspore.cn/toolkits/mindcv/ssd/ssd_mobilenetv3-53d9f6e9.ckpt) |
+
+</div>
+
+## References
+
+[1] Liu, W., Anguelov, D., Erhan, D., Szegedy, C., Reed, S., Fu, C. Y., & Berg, A. C. (2016). SSD: Single Shot Multibox Detector. In Computer Vision–ECCV 2016: 14th European Conference, Amsterdam, The Netherlands, October 11–14, 2016, Proceedings, Part I 14 (pp. 21-37). Springer International Publishing.

examples/det/ssd/callbacks.py

@@ -0,0 +1,130 @@
+import os
+import stat
+
+from utils import apply_eval
+
+from mindspore import log as logger
+from mindspore import save_checkpoint
+from mindspore.train.callback import Callback, CheckpointConfig, LossMonitor, ModelCheckpoint, TimeMonitor
+
+
+class EvalCallBack(Callback):
+    """
+    Evaluation callback when training.
+
+    Args:
+        eval_function (function): evaluation function.
+        eval_param_dict (dict): evaluation parameters' configure dict.
+        interval (int): run evaluation interval, default is 1.
+        eval_start_epoch (int): evaluation start epoch, default is 1.
+        save_best_ckpt (bool): Whether to save best checkpoint, default is True.
+        best_ckpt_name (str): best checkpoint name, default is `best.ckpt`.
+        metrics_name (str): evaluation metrics name, default is `acc`.
+
+    Returns:
+        None
+
+    Examples:
+        >>> EvalCallBack(eval_function, eval_param_dict)
+    """
+
+    def __init__(
+        self,
+        eval_function,
+        eval_param_dict,
+        interval=1,
+        eval_start_epoch=1,
+        save_best_ckpt=True,
+        ckpt_directory="./",
+        best_ckpt_name="best.ckpt",
+        metrics_name="acc",
+    ):
+        super(EvalCallBack, self).__init__()
+        self.eval_function = eval_function
+        self.eval_param_dict = eval_param_dict
+        self.eval_start_epoch = eval_start_epoch
+
+        if interval < 1:
+            raise ValueError("interval should >= 1.")
+
+        self.interval = interval
+        self.save_best_ckpt = save_best_ckpt
+        self.best_res = 0
+        self.best_epoch = 0
+
+        if not os.path.isdir(ckpt_directory):
+            os.makedirs(ckpt_directory)
+
+        self.best_ckpt_path = os.path.join(ckpt_directory, best_ckpt_name)
+        self.metrics_name = metrics_name
+
+    def remove_ckpoint_file(self, file_name):
+        """Remove the specified checkpoint file from this checkpoint manager and also from the directory."""
+        try:
+            os.chmod(file_name, stat.S_IWRITE)
+            os.remove(file_name)
+        except OSError:
+            logger.warning("OSError, failed to remove the older ckpt file %s.", file_name)
+        except ValueError:
+            logger.warning("ValueError, failed to remove the older ckpt file %s.", file_name)
+
+    def on_train_epoch_end(self, run_context):
+        """Callback when epoch end."""
+        cb_params = run_context.original_args()
+        cur_epoch = cb_params.cur_epoch_num
+
+        if cur_epoch >= self.eval_start_epoch and (cur_epoch - self.eval_start_epoch) % self.interval == 0:
+            res = self.eval_function(self.eval_param_dict)
+            print("epoch: {}, {}: {}".format(cur_epoch, self.metrics_name, res), flush=True)
+
+            if res >= self.best_res:
+                self.best_res = res
+                self.best_epoch = cur_epoch
+                print("update best result: {}".format(res), flush=True)
+
+                if self.save_best_ckpt:
+                    if os.path.exists(self.best_ckpt_path):
+                        self.remove_ckpoint_file(self.best_ckpt_path)
+
+                    save_checkpoint(cb_params.train_network, self.best_ckpt_path)
+                    print("update best checkpoint at: {}".format(self.best_ckpt_path), flush=True)
+
+    def on_train_end(self, run_context):
+        print(
+            "End training, the best {0} is: {1}, the best {0} epoch is {2}".format(
+                self.metrics_name, self.best_res, self.best_epoch
+            ),
+            flush=True,
+        )
+
+
+def get_ssd_callbacks(args, steps_per_epoch, rank_id):
+    ckpt_config = CheckpointConfig(keep_checkpoint_max=args.keep_checkpoint_max)
+    ckpt_cb = ModelCheckpoint(prefix="ssd", directory=args.ckpt_save_dir, config=ckpt_config)
+
+    if rank_id == 0:
+        return [TimeMonitor(data_size=steps_per_epoch), LossMonitor(), ckpt_cb]
+
+    return [TimeMonitor(data_size=steps_per_epoch), LossMonitor()]
+
+
+def get_ssd_eval_callback(eval_net, eval_dataset, args):
+    if args.dataset == "coco":
+        anno_json = os.path.join(args.data_dir, "annotations/instances_val2017.json")
+    else:
+        raise NotImplementedError
+
+    eval_param_dict = {"net": eval_net, "dataset": eval_dataset, "anno_json": anno_json, "args": args}
+
+    eval_cb = EvalCallBack(
+        apply_eval,
+        eval_param_dict,
+        interval=args.eval_interval,
+        eval_start_epoch=args.eval_start_epoch,
+        save_best_ckpt=True,
+        ckpt_directory=args.ckpt_save_dir,
+        best_ckpt_name="best.ckpt",
+        metrics_name="mAP",
+    )
+
+    return eval_cb