IT评测·应用市场-qidao123.com技术社区
标题:
昇思25天学习打卡
[打印本页]
作者:
忿忿的泥巴坨
时间:
2024-7-31 15:26
标题:
昇思25天学习打卡
FCN图像语义分割
FCN全卷网络,舍弃了传统的全毗连层,仅使用卷积和池化等操作完成,end-to-end的像素集预测网络。
网络特点:
不含全毗连层(fc)的全卷积(fully conv)网络,可顺应任意尺寸输入。
增大数据尺寸的反卷积(deconv)层,能够输出精致的结果。
结合差异深度层结果的跳级(skip)结构,同时确保鲁棒性和准确性。
语义分割
图像语义分割(semantic segmentation)是图像处置惩罚和机器视觉技术中关于图像理解的紧张一环,AI范畴中一个紧张分支,常被应用于人脸识别、物体检测、医学影像、卫星图像分析、自动驾驶感知等范畴。
这个就不消过多赘述了,目标检测是画框,语义分割就是把目标从图内里抠出来。
1. 数据处置惩罚
起首下载数据
from download import download
url = "https://mindspore-website.obs.cn-north-4.myhuaweicloud.com/notebook/datasets/dataset_fcn8s.tar"
download(url, "./dataset", kind="tar", replace=True)
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数据预处置惩罚
import numpy as np
import cv2
import mindspore.dataset as ds
class SegDataset:
def __init__(self,
image_mean,
image_std,
data_file='',
batch_size=32,
crop_size=512,
max_scale=2.0,
min_scale=0.5,
ignore_label=255,
num_classes=21,
num_readers=2,
num_parallel_calls=4):
self.data_file = data_file
self.batch_size = batch_size
self.crop_size = crop_size
self.image_mean = np.array(image_mean, dtype=np.float32)
self.image_std = np.array(image_std, dtype=np.float32)
self.max_scale = max_scale
self.min_scale = min_scale
self.ignore_label = ignore_label
self.num_classes = num_classes
self.num_readers = num_readers
self.num_parallel_calls = num_parallel_calls
max_scale > min_scale
# 初始化数据集的参数,如文件路径、批次大小、裁剪大小、缩放比例、忽略标签、类别数、读取线程数和并行调用数。
def preprocess_dataset(self, image, label):
image_out = cv2.imdecode(np.frombuffer(image, dtype=np.uint8), cv2.IMREAD_COLOR)
label_out = cv2.imdecode(np.frombuffer(label, dtype=np.uint8), cv2.IMREAD_GRAYSCALE)
sc = np.random.uniform(self.min_scale, self.max_scale)
new_h, new_w = int(sc * image_out.shape[0]), int(sc * image_out.shape[1])
image_out = cv2.resize(image_out, (new_w, new_h), interpolation=cv2.INTER_CUBIC)
label_out = cv2.resize(label_out, (new_w, new_h), interpolation=cv2.INTER_NEAREST)
image_out = (image_out - self.image_mean) / self.image_std
out_h, out_w = max(new_h, self.crop_size), max(new_w, self.crop_size)
pad_h, pad_w = out_h - new_h, out_w - new_w
if pad_h > 0 or pad_w > 0:
image_out = cv2.copyMakeBorder(image_out, 0, pad_h, 0, pad_w, cv2.BORDER_CONSTANT, value=0)
label_out = cv2.copyMakeBorder(label_out, 0, pad_h, 0, pad_w, cv2.BORDER_CONSTANT, value=self.ignore_label)
offset_h = np.random.randint(0, out_h - self.crop_size + 1)
offset_w = np.random.randint(0, out_w - self.crop_size + 1)
image_out = image_out[offset_h: offset_h + self.crop_size, offset_w: offset_w + self.crop_size, :]
label_out = label_out[offset_h: offset_h + self.crop_size, offset_w: offset_w+self.crop_size]
if np.random.uniform(0.0, 1.0) > 0.5:
image_out = image_out[:, ::-1, :]
label_out = label_out[:, ::-1]
image_out = image_out.transpose((2, 0, 1))
image_out = image_out.copy()
label_out = label_out.copy()
label_out = label_out.astype("int32")
return image_out, label_out
# 随机缩放图像和标签。对图像进行标准化(减去均值,除以标准差)。对图像和标签进行裁剪和翻转等数据增强操作。将图像转换为适合深度学习模型的格式(CHW)。
def get_dataset(self):
ds.config.set_numa_enable(True)
dataset = ds.MindDataset(self.data_file, columns_list=["data", "label"],
shuffle=True, num_parallel_workers=self.num_readers)
transforms_list = self.preprocess_dataset
dataset = dataset.map(operations=transforms_list, input_columns=["data", "label"],
output_columns=["data", "label"],
num_parallel_workers=self.num_parallel_calls)
dataset = dataset.shuffle(buffer_size=self.batch_size * 10)
dataset = dataset.batch(self.batch_size, drop_remainder=True)
return dataset
# 使用 MindDataset 从 self.data_file 读取数据,指定需要的列("data" 和 "label")以及读取线程数。将 preprocess_dataset 方法应用于数据集。打乱数据集,并按指定的批次大小进行批处理。
# 定义创建数据集的参数
IMAGE_MEAN = [103.53, 116.28, 123.675]
IMAGE_STD = [57.375, 57.120, 58.395]
DATA_FILE = "dataset/dataset_fcn8s/mindname.mindrecord"
# 定义模型训练参数
train_batch_size = 4
crop_size = 512
min_scale = 0.5
max_scale = 2.0
ignore_label = 255
num_classes = 21
# 实例化Dataset
dataset = SegDataset(image_mean=IMAGE_MEAN,
image_std=IMAGE_STD,
data_file=DATA_FILE,
batch_size=train_batch_size,
crop_size=crop_size,
max_scale=max_scale,
min_scale=min_scale,
ignore_label=ignore_label,
num_classes=num_classes,
num_readers=2,
num_parallel_calls=4)
dataset = dataset.get_dataset()
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2. 构建网络
import mindspore.nn as nn
class FCN8s(nn.Cell):
def __init__(self, n_class):
super().__init__()
self.n_class = n_class
self.conv1 = nn.SequentialCell(
nn.Conv2d(in_channels=3, out_channels=64,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(64),
nn.ReLU(),
nn.Conv2d(in_channels=64, out_channels=64,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(64),
nn.ReLU()
)
self.pool1 = nn.MaxPool2d(kernel_size=2, stride=2)
self.conv2 = nn.SequentialCell(
nn.Conv2d(in_channels=64, out_channels=128,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(128),
nn.ReLU(),
nn.Conv2d(in_channels=128, out_channels=128,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(128),
nn.ReLU()
)
self.pool2 = nn.MaxPool2d(kernel_size=2, stride=2)
self.conv3 = nn.SequentialCell(
nn.Conv2d(in_channels=128, out_channels=256,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(256),
nn.ReLU(),
nn.Conv2d(in_channels=256, out_channels=256,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(256),
nn.ReLU(),
nn.Conv2d(in_channels=256, out_channels=256,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(256),
nn.ReLU()
)
self.pool3 = nn.MaxPool2d(kernel_size=2, stride=2)
self.conv4 = nn.SequentialCell(
nn.Conv2d(in_channels=256, out_channels=512,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(512),
nn.ReLU(),
nn.Conv2d(in_channels=512, out_channels=512,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(512),
nn.ReLU(),
nn.Conv2d(in_channels=512, out_channels=512,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(512),
nn.ReLU()
)
self.pool4 = nn.MaxPool2d(kernel_size=2, stride=2)
self.conv5 = nn.SequentialCell(
nn.Conv2d(in_channels=512, out_channels=512,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(512),
nn.ReLU(),
nn.Conv2d(in_channels=512, out_channels=512,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(512),
nn.ReLU(),
nn.Conv2d(in_channels=512, out_channels=512,
kernel_size=3, weight_init='xavier_uniform'),
nn.BatchNorm2d(512),
nn.ReLU()
)
self.pool5 = nn.MaxPool2d(kernel_size=2, stride=2)
self.conv6 = nn.SequentialCell(
nn.Conv2d(in_channels=512, out_channels=4096,
kernel_size=7, weight_init='xavier_uniform'),
nn.BatchNorm2d(4096),
nn.ReLU(),
)
self.conv7 = nn.SequentialCell(
nn.Conv2d(in_channels=4096, out_channels=4096,
kernel_size=1, weight_init='xavier_uniform'),
nn.BatchNorm2d(4096),
nn.ReLU(),
)
self.score_fr = nn.Conv2d(in_channels=4096, out_channels=self.n_class,
kernel_size=1, weight_init='xavier_uniform')
self.upscore2 = nn.Conv2dTranspose(in_channels=self.n_class, out_channels=self.n_class,
kernel_size=4, stride=2, weight_init='xavier_uniform')
self.score_pool4 = nn.Conv2d(in_channels=512, out_channels=self.n_class,
kernel_size=1, weight_init='xavier_uniform')
self.upscore_pool4 = nn.Conv2dTranspose(in_channels=self.n_class, out_channels=self.n_class,
kernel_size=4, stride=2, weight_init='xavier_uniform')
self.score_pool3 = nn.Conv2d(in_channels=256, out_channels=self.n_class,
kernel_size=1, weight_init='xavier_uniform')
self.upscore8 = nn.Conv2dTranspose(in_channels=self.n_class, out_channels=self.n_class,
kernel_size=16, stride=8, weight_init='xavier_uniform')
def construct(self, x):
x1 = self.conv1(x)
p1 = self.pool1(x1)
x2 = self.conv2(p1)
p2 = self.pool2(x2)
x3 = self.conv3(p2)
p3 = self.pool3(x3)
x4 = self.conv4(p3)
p4 = self.pool4(x4)
x5 = self.conv5(p4)
p5 = self.pool5(x5)
x6 = self.conv6(p5)
x7 = self.conv7(x6)
sf = self.score_fr(x7)
u2 = self.upscore2(sf)
s4 = self.score_pool4(p4)
f4 = s4 + u2
u4 = self.upscore_pool4(f4)
s3 = self.score_pool3(p3)
f3 = s3 + u4
out = self.upscore8(f3)
return out
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3. 训练准备
下载预训练VGG-16模型
from download import download
from mindspore import load_checkpoint, load_param_into_net
url = "https://mindspore-website.obs.cn-north-4.myhuaweicloud.com/notebook/datasets/fcn8s_vgg16_pretrain.ckpt"
download(url, "fcn8s_vgg16_pretrain.ckpt", replace=True)
def load_vgg16():
ckpt_vgg16 = "fcn8s_vgg16_pretrain.ckpt"
param_vgg = load_checkpoint(ckpt_vgg16)
load_param_into_net(net, param_vgg)
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评估函数定义
import numpy as np
import mindspore as ms
import mindspore.nn as nn
import mindspore.train as train
class PixelAccuracy(train.Metric):
def __init__(self, num_class=21):
super(PixelAccuracy, self).__init__()
self.num_class = num_class
def _generate_matrix(self, gt_image, pre_image):
mask = (gt_image >= 0) & (gt_image < self.num_class)
label = self.num_class * gt_image[mask].astype('int') + pre_image[mask]
count = np.bincount(label, minlength=self.num_class**2)
confusion_matrix = count.reshape(self.num_class, self.num_class)
return confusion_matrix
def clear(self):
self.confusion_matrix = np.zeros((self.num_class,) * 2)
def update(self, *inputs):
y_pred = inputs[0].asnumpy().argmax(axis=1)
y = inputs[1].asnumpy().reshape(4, 512, 512)
self.confusion_matrix += self._generate_matrix(y, y_pred)
def eval(self):
pixel_accuracy = np.diag(self.confusion_matrix).sum() / self.confusion_matrix.sum()
return pixel_accuracy
class PixelAccuracyClass(train.Metric):
def __init__(self, num_class=21):
super(PixelAccuracyClass, self).__init__()
self.num_class = num_class
def _generate_matrix(self, gt_image, pre_image):
mask = (gt_image >= 0) & (gt_image < self.num_class)
label = self.num_class * gt_image[mask].astype('int') + pre_image[mask]
count = np.bincount(label, minlength=self.num_class**2)
confusion_matrix = count.reshape(self.num_class, self.num_class)
return confusion_matrix
def update(self, *inputs):
y_pred = inputs[0].asnumpy().argmax(axis=1)
y = inputs[1].asnumpy().reshape(4, 512, 512)
self.confusion_matrix += self._generate_matrix(y, y_pred)
def clear(self):
self.confusion_matrix = np.zeros((self.num_class,) * 2)
def eval(self):
mean_pixel_accuracy = np.diag(self.confusion_matrix) / self.confusion_matrix.sum(axis=1)
mean_pixel_accuracy = np.nanmean(mean_pixel_accuracy)
return mean_pixel_accuracy
class MeanIntersectionOverUnion(train.Metric):
def __init__(self, num_class=21):
super(MeanIntersectionOverUnion, self).__init__()
self.num_class = num_class
def _generate_matrix(self, gt_image, pre_image):
mask = (gt_image >= 0) & (gt_image < self.num_class)
label = self.num_class * gt_image[mask].astype('int') + pre_image[mask]
count = np.bincount(label, minlength=self.num_class**2)
confusion_matrix = count.reshape(self.num_class, self.num_class)
return confusion_matrix
def update(self, *inputs):
y_pred = inputs[0].asnumpy().argmax(axis=1)
y = inputs[1].asnumpy().reshape(4, 512, 512)
self.confusion_matrix += self._generate_matrix(y, y_pred)
def clear(self):
self.confusion_matrix = np.zeros((self.num_class,) * 2)
def eval(self):
mean_iou = np.diag(self.confusion_matrix) / (
np.sum(self.confusion_matrix, axis=1) + np.sum(self.confusion_matrix, axis=0) -
np.diag(self.confusion_matrix))
mean_iou = np.nanmean(mean_iou)
return mean_iou
class FrequencyWeightedIntersectionOverUnion(train.Metric):
def __init__(self, num_class=21):
super(FrequencyWeightedIntersectionOverUnion, self).__init__()
self.num_class = num_class
def _generate_matrix(self, gt_image, pre_image):
mask = (gt_image >= 0) & (gt_image < self.num_class)
label = self.num_class * gt_image[mask].astype('int') + pre_image[mask]
count = np.bincount(label, minlength=self.num_class**2)
confusion_matrix = count.reshape(self.num_class, self.num_class)
return confusion_matrix
def update(self, *inputs):
y_pred = inputs[0].asnumpy().argmax(axis=1)
y = inputs[1].asnumpy().reshape(4, 512, 512)
self.confusion_matrix += self._generate_matrix(y, y_pred)
def clear(self):
self.confusion_matrix = np.zeros((self.num_class,) * 2)
def eval(self):
freq = np.sum(self.confusion_matrix, axis=1) / np.sum(self.confusion_matrix)
iu = np.diag(self.confusion_matrix) / (
np.sum(self.confusion_matrix, axis=1) + np.sum(self.confusion_matrix, axis=0) -
np.diag(self.confusion_matrix))
frequency_weighted_iou = (freq[freq > 0] * iu[freq > 0]).sum()
return frequency_weighted_iou
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模型训练
import mindspore
from mindspore import Tensor
import mindspore.nn as nn
from mindspore.train import ModelCheckpoint, CheckpointConfig, LossMonitor, TimeMonitor, Model
device_target = "Ascend"
mindspore.set_context(mode=mindspore.PYNATIVE_MODE, device_target=device_target)
train_batch_size = 4
num_classes = 21
# 初始化模型结构
net = FCN8s(n_class=21)
# 导入vgg16预训练参数
load_vgg16()
# 计算学习率
min_lr = 0.0005
base_lr = 0.05
train_epochs = 1
iters_per_epoch = dataset.get_dataset_size()
total_step = iters_per_epoch * train_epochs
lr_scheduler = mindspore.nn.cosine_decay_lr(min_lr,
base_lr,
total_step,
iters_per_epoch,
decay_epoch=2)
lr = Tensor(lr_scheduler[-1])
# 定义损失函数
loss = nn.CrossEntropyLoss(ignore_index=255)
# 定义优化器
optimizer = nn.Momentum(params=net.trainable_params(), learning_rate=lr, momentum=0.9, weight_decay=0.0001)
# 定义loss_scale
scale_factor = 4
scale_window = 3000
loss_scale_manager = ms.amp.DynamicLossScaleManager(scale_factor, scale_window)
# 初始化模型
if device_target == "Ascend":
model = Model(net, loss_fn=loss, optimizer=optimizer, loss_scale_manager=loss_scale_manager, metrics={"pixel accuracy": PixelAccuracy(), "mean pixel accuracy": PixelAccuracyClass(), "mean IoU": MeanIntersectionOverUnion(), "frequency weighted IoU": FrequencyWeightedIntersectionOverUnion()})
else:
model = Model(net, loss_fn=loss, optimizer=optimizer, metrics={"pixel accuracy": PixelAccuracy(), "mean pixel accuracy": PixelAccuracyClass(), "mean IoU": MeanIntersectionOverUnion(), "frequency weighted IoU": FrequencyWeightedIntersectionOverUnion()})
# 设置ckpt文件保存的参数
time_callback = TimeMonitor(data_size=iters_per_epoch)
loss_callback = LossMonitor()
callbacks = [time_callback, loss_callback]
save_steps = 330
keep_checkpoint_max = 5
config_ckpt = CheckpointConfig(save_checkpoint_steps=10,
keep_checkpoint_max=keep_checkpoint_max)
ckpt_callback = ModelCheckpoint(prefix="FCN8s",
directory="./ckpt",
config=config_ckpt)
callbacks.append(ckpt_callback)
model.train(train_epochs, dataset, callbacks=callbacks)
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4. 模型评估
IMAGE_MEAN = [103.53, 116.28, 123.675]
IMAGE_STD = [57.375, 57.120, 58.395]
DATA_FILE = "dataset/dataset_fcn8s/mindname.mindrecord"
# 下载已训练好的权重文件
url = "https://mindspore-website.obs.cn-north-4.myhuaweicloud.com/notebook/datasets/FCN8s.ckpt"
download(url, "FCN8s.ckpt", replace=True)
net = FCN8s(n_class=num_classes)
ckpt_file = "FCN8s.ckpt"
param_dict = load_checkpoint(ckpt_file)
load_param_into_net(net, param_dict)
if device_target == "Ascend":
model = Model(net, loss_fn=loss, optimizer=optimizer, loss_scale_manager=loss_scale_manager, metrics={"pixel accuracy": PixelAccuracy(), "mean pixel accuracy": PixelAccuracyClass(), "mean IoU": MeanIntersectionOverUnion(), "frequency weighted IoU": FrequencyWeightedIntersectionOverUnion()})
else:
model = Model(net, loss_fn=loss, optimizer=optimizer, metrics={"pixel accuracy": PixelAccuracy(), "mean pixel accuracy": PixelAccuracyClass(), "mean IoU": MeanIntersectionOverUnion(), "frequency weighted IoU": FrequencyWeightedIntersectionOverUnion()})
# 实例化Dataset
dataset = SegDataset(image_mean=IMAGE_MEAN,
image_std=IMAGE_STD,
data_file=DATA_FILE,
batch_size=train_batch_size,
crop_size=crop_size,
max_scale=max_scale,
min_scale=min_scale,
ignore_label=ignore_label,
num_classes=num_classes,
num_readers=2,
num_parallel_calls=4)
dataset_eval = dataset.get_dataset()
model.eval(dataset_eval)
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5. 模型推理
import cv2
import matplotlib.pyplot as plt
net = FCN8s(n_class=num_classes)
# 设置超参
ckpt_file = "FCN8s.ckpt"
param_dict = load_checkpoint(ckpt_file)
load_param_into_net(net, param_dict)
eval_batch_size = 4
img_lst = []
mask_lst = []
res_lst = []
# 推理效果展示(上方为输入图片,下方为推理效果图片)
plt.figure(figsize=(8, 5))
show_data = next(dataset_eval.create_dict_iterator())
show_images = show_data["data"].asnumpy()
mask_images = show_data["label"].reshape([4, 512, 512])
show_images = np.clip(show_images, 0, 1)
for i in range(eval_batch_size):
img_lst.append(show_images[i])
mask_lst.append(mask_images[i])
res = net(show_data["data"]).asnumpy().argmax(axis=1)
for i in range(eval_batch_size):
plt.subplot(2, 4, i + 1)
plt.imshow(img_lst[i].transpose(1, 2, 0))
plt.axis("off")
plt.subplots_adjust(wspace=0.05, hspace=0.02)
plt.subplot(2, 4, i + 5)
plt.imshow(res[i])
plt.axis("off")
plt.subplots_adjust(wspace=0.05, hspace=0.02)
plt.show()
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