基于megengine实现YoloX【附部分源码】

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前言

本文以megengine为深度学习框架实现yolox，并训练自己的数据集及可进行测试coco数据集

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一、YOLOX网上说法

YOLOX是一个高性能的anchor-free版本，它超过了YOLOv3到YOLOv5，并且支持MegEngine、ONNX、TensorRT、ncnn和OpenVINO，为大家提供了加速和部署的支持。

在原始论文的题目可以看出，YOLOX在2021年超过了所有YOLO系列的版本

论文地址:https://arxiv.org/pdf/2107.08430.pdf

论文提供的效果图：

可见yolox远超yolo5及efficientdet

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二、YOLOX代码实现

本工程代码结构如下：

BaseModel：存放COCO训练好的权重文件
core：一些评价指标的文件
data：数据加载器
nets：网络结构
utils：一些重要的数据处理的文件‘
Ctu_Yolox.py：主函数入口

1.网络结构实现

这里实现的yolox版本包括：
yolox_darknet、yolox_nano、yolox_tiny、yolox_s、yolox_m、yolox_l、yolox_x

yolox主模型入口

class YOLOX(M.Module):
    yolox_model={
        'yolox_x':{
            'depth':1.33,
            'width':1.25
        },
        'yolox_l':{
            'depth':1.0,
            'width':1.0
        },
        'yolox_m':{
            'depth':0.67,
            'width':0.75
        },
        'yolox_s':{
            'depth':0.33,
            'width':0.50
        },
        'yolox_tiny':{
            'depth':0.33,
            'width':0.375
        },
        'yolox_nano':{
            'depth':0.33,
            'width':0.25
        },
        'yolox_darknet':{
            'depth':1.0,
            'width':1.0
        },
    }
    def __init__(self, num_classes=80,network_name='yolox_s'):
        super().__init__()
        self.network_name=network_name
        if self.network_name !='yolox_darknet':
            in_channels = [256, 512, 1024]
            self.backbone = YOLOPAFPN(self.yolox_model[self.network_name]['depth'], self.yolox_model[self.network_name]['width'], in_channels=in_channels)
            self.head = YOLOXHead(num_classes, self.yolox_model[self.network_name]['width'], in_channels=in_channels)
        else:
            self.backbone = YOLOFPN()
            self.head = YOLOXHead(num_classes, self.yolox_model[self.network_name]['width'], in_channels=[128, 256, 512], act="lrelu")
    def forward(self, x, targets=None):
        fpn_outs = self.backbone(x)

        if self.training:
            assert targets is not None
            loss, iou_loss, conf_loss, cls_loss, l1_loss, num_fg = self.head(fpn_outs, targets, x)
            outputs = {
                "total_loss": loss,
                "iou_loss": iou_loss,
                "l1_loss": l1_loss,
                "conf_loss": conf_loss,
                "cls_loss": cls_loss,
                "num_fg": num_fg,
            }
        else:
            outputs = self.head(fpn_outs)

        return outputs

2.代码框架实现

这里主要是Ctu_Yolox.py代码实现

GPU设置

这里只需要修改环境变量即可

os.environ['CUDA_VISIBLE_DEVICES']=USEGPU

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数据预处理

这里对数据进行归一化处理

self.rgb_means = (0.485, 0.456, 0.406)
self.std = (0.229, 0.224, 0.225)

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数据加载器

这里使用的是VOC数据集

def CreateDataList_Detection(IMGDir,XMLDir,train_split):
    ImgList = os.listdir(IMGDir)
    XmlList = os.listdir(XMLDir)
    classes = []
    dataList=[]
    for each_jpg in ImgList:
        each_xml = each_jpg.split('.')[0] + '.xml'
        if each_xml in XmlList:
            dataList.append([os.path.join(IMGDir,each_jpg),os.path.join(XMLDir,each_xml)])
            with open(os.path.join(XMLDir,each_xml), "r", encoding="utf-8") as in_file:
                tree = ET.parse(in_file)
                root = tree.getroot()
                for obj in root.iter('object'):
                    cls = obj.find('name').text
                    if cls not in classes:
                        classes.append(cls)
    random.shuffle(dataList)
    if train_split <=0 or train_split >=1:
        train_data_list = dataList
        val_data_list = dataList
    else:
        train_data_list = dataList[:int(len(dataList)*train_split)]
        val_data_list = dataList[int(len(dataList)*train_split):]
    return train_data_list, val_data_list, classes

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数据迭代器

class VOCDetection(Dataset):
    def __init__(self, data_list,classes_names, img_size=(640, 640), preproc=None):
        super().__init__(img_size)
        self.data_list = data_list
        self.image_set = classes_names
        self.img_size = img_size
        self.preproc = preproc
        self.target_transform = AnnotationTransform(classes_names)
        self.ids = list()

    def __len__(self):
        return len(self.data_list)

    def load_anno(self, index):
        target = ET.parse(self.data_list[index][1]).getroot()
        if self.target_transform is not None:
            target = self.target_transform(target)
        return target

    def pull_item(self, index):
        img = cv2.imread(self.data_list[index][0], cv2.IMREAD_COLOR)
        height, width, _ = img.shape
        target = self.load_anno(index)
        img_info = (width, height)
        return img, target, img_info, index

    @Dataset.resize_getitem
    def __getitem__(self, index):
        img, target, img_info, img_id = self.pull_item(index)

        if self.preproc is not None:
            img, target = self.preproc(img, target, self.input_dim)

        return img, target, img_info, img_id

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模型构建

self.network_name = network_name
self.model = YOLOX(num_classes=len(self.classes_names),network_name=self.network_name)

这里的networ_name就是制定使用的yolox的版本

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模型训练

for self.epoch in range(0, TrainNum):
    if self.epoch + 1 == (TrainNum - no_aug_epochs) or (not self.aug_Flag):
        self.train_loader.close_mosaic()
        self.model.head.use_l1 = True

    for self.iter in range(self.max_iter):
        iter_start_time = time.time()
        inps, targets = self.prefetcher.next()
        inps, targets = mge.tensor(inps), mge.tensor(targets)
        data_end_time = time.time()

        with self.grad_manager:
            outputs = self.model(inps, targets)
            loss = outputs["total_loss"]
            self.grad_manager.backward(loss)

        self.optimizer.step().clear_grad()

        if self.emaFlag:
            self.ema_model.update()

        lr = self.lr_scheduler.update_lr(self.progress_in_iter + 1)
        for param_group in self.optimizer.param_groups:
            param_group["lr"] = lr

        iter_end_time = time.time()
        self.meter.update(
            iter_time=iter_end_time - iter_start_time,
            data_time=data_end_time - iter_start_time,
            lr=lr,
            **outputs,
        )
        
        left_iters = self.max_iter * TrainNum - (self.progress_in_iter + 1)
        eta_seconds = self.meter["iter_time"].global_avg * left_iters
        eta_str = "ETA: {}".format(datetime.timedelta(seconds=int(eta_seconds)))

        progress_str = "epoch: {}/{}, iter: {}/{}".format(
            self.epoch + 1, TrainNum, self.iter + 1, self.max_iter
        )
        loss_meter = self.meter.get_filtered_meter("loss")
        loss_str_list = []
        for k, v in loss_meter.items():
            single_loss_str = "{}: {:.6f}".format(k, float(v.latest))

            loss_str_list.append(single_loss_str)

        loss_str = ", ".join(loss_str_list)

        time_meter = self.meter.get_filtered_meter("time")
        time_str = ", ".join([
            "{}: {:.3f}s".format(k, float(v.avg))
            for k, v in time_meter.items()
        ])

        print(
            "{}, {}, {}, lr: {:.3e}".format(
                progress_str,
                time_str,
                loss_str,
                self.meter["lr"].latest,
            )
            + (", size: {:d}, {}".format(self.image_size, eta_str))
        )
        self.meter.clear_meters()

    mge.save(
        {"epoch": 0, "state_dict": self.model.state_dict(),'classes_names':self.classes_names,'image_size':self.image_size,'network_name':self.network_name}, os.path.join(ModelPath,'final.pkl'),
    )

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模型预测

def predict(self,img,score=0.35,nms=0.35):
    img_info = {"id": 0}
    height, width = img.shape[:2]
    img_info["height"] = height
    img_info["width"] = width
    img_info["raw_img"] = img
    img, ratio = preprocess(img, (self.image_size,self.image_size), self.rgb_means, self.std)
    img_info["ratio"] = ratio
    img = F.expand_dims(mge.tensor(img), 0)
    outputs = ctu.model(img)
    outputs = postprocess(outputs, len(self.classes_names), 0.01, nms)
    # huizhi
    ratio = img_info["ratio"]
    img = img_info["raw_img"]
    output = outputs[0].numpy()
    bboxes = output[:, 0:4] / ratio
    cls = output[:, 6]
    scores = output[:, 4] * output[:, 5]
    vis_res = vis(img, bboxes, scores, cls, score, self.classes_names)
    return vis_res

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三、效果展示

自定义数据集

待定

COCO数据集