我想在以下这段代码中,添加显示标有特征点的图像的功能。def cnn_feature_extract(image,scales=[.25, 0.50, 1.0], nfeatures = 1000): if len(image.shape) == 2: image = image[:, :, np.newaxis] image = np.repeat(image, 3, -1) # TODO: switch to PIL.Image due to deprecation of scipy.misc.imresize. resized_image = image if max(resized_image.shape) > max_edge: resized_image = scipy.misc.imresize( resized_image, max_edge / max(resized_image.shape) ).astype('float') if sum(resized_image.shape[: 2]) > max_sum_edges: resized_image = scipy.misc.imresize( resized_image, max_sum_edges / sum(resized_image.shape[: 2]) ).astype('float') fact_i = image.shape[0] / resized_image.shape[0] fact_j = image.shape[1] / resized_image.shape[1] input_image = preprocess_image( resized_image, preprocessing="torch" ) with torch.no_grad(): if multiscale: keypoints, scores, descriptors = process_multiscale( torch.tensor( input_image[np.newaxis, :, :, :].astype(np.float32), device=device ), model, scales ) else: keypoints, scores, descriptors = process_multiscale( torch.tensor( input_image[np.newaxis, :, :, :].astype(np.float32), device=device ), model, scales ) # Input image coordinates keypoints[:, 0] *= fact_i keypoints[:, 1] *= fact_j # i, j -> u, v keypoints = keypoints[:, [1, 0, 2]] if nfeatures != -1: #根据scores排序 scores2 = np.array([scores]).T res = np.hstack((scores2, keypoints)) res = res[np.lexsort(-res[:, ::-1].T)] res = np.hstack((res, descriptors)) #取前几个 scores = res[0:nfeatures, 0].copy() keypoints = res[0:nfeatures, 1:4].copy() descriptors = res[0:nfeatures, 4:].copy() del res return keypoints, scores, descriptors
时间: 2024-01-04 19:02:04 浏览: 33
可以使用OpenCV库中的cv2.drawKeypoints()函数来显示标有特征点的图像。具体实现如下:
1. 导入OpenCV库:import cv2
2. 在函数中添加以下代码,绘制特征点:
```
img_with_keypoints = cv2.drawKeypoints(image, keypoints, np.array([]), (255,0,0), cv2.DRAW_MATCHES_FLAGS_DRAW_RICH_KEYPOINTS)
cv2.imshow("Image with Keypoints", img_with_keypoints)
cv2.waitKey(0)
cv2.destroyAllWindows()
```
这段代码将在窗口中显示标有特征点的图像。注意,要在函数中添加完整的代码,包括导入OpenCV库等。
相关问题
解释代码scales = MinMaxScaler(feature_range=(0, 1))
这段代码使用了`MinMaxScaler`函数来对数据进行特征缩放,将特征的取值范围限制在0到1之间。`feature_range`参数指定了缩放后的取值范围,其中0表示特征最小值,1表示特征最大值。`MinMaxScaler`是一种常用的数据预处理方法,适用于处理具有不同取值范围的特征,以保证它们具有相似的尺度。这有助于某些机器学习算法更好地处理数据,提高模型的性能和稳定性。
请给出用于物体检测获取交通标志位于图像中位置的Faster R-CNN的详细代码
以下是使用 Faster R-CNN 进行交通标志检测的示例代码。这里使用 PyTorch 框架实现。
首先,我们需要定义 Faster R-CNN 模型的架构,这里使用 ResNet-50 作为特征提取器。我们还需要定义 RPN(Region Proposal Network)和 RoI(Region of Interest)池化层。
```python
import torch
import torch.nn as nn
import torchvision.models as models
class FasterRCNN(nn.Module):
def __init__(self, num_classes):
super(FasterRCNN, self).__init__()
# backbone network
self.backbone = models.resnet50(pretrained=True)
# RPN (Region Proposal Network)
self.rpn = nn.Sequential(
nn.Conv2d(2048, 512, kernel_size=3, stride=1, padding=1),
nn.ReLU(),
nn.Conv2d(512, 3 * 2, kernel_size=1, stride=1, padding=0)
)
# RoI (Region of Interest) Pooling
self.roi_pool = nn.AdaptiveMaxPool2d((7, 7))
# classifier and regressor
self.classifier = nn.Sequential(
nn.Linear(2048 * 7 * 7, 4096),
nn.ReLU(),
nn.Linear(4096, 4096),
nn.ReLU(),
nn.Linear(4096, num_classes)
)
self.regressor = nn.Sequential(
nn.Linear(2048 * 7 * 7, 4096),
nn.ReLU(),
nn.Linear(4096, 4096),
nn.ReLU(),
nn.Linear(4096, num_classes * 4)
)
def forward(self, x):
features = self.backbone(x)
rpn_output = self.rpn(features)
# reshape RPN output
rpn_output = rpn_output.permute(0, 2, 3, 1).contiguous().view(x.size(0), -1, 2)
# RoI proposal
proposals = self.proposal_generator(features, rpn_output)
# RoI pooling
rois = self.roi_pool(features, proposals)
# classifier and regressor
roi_features = rois.view(rois.size(0), -1)
classifier_output = self.classifier(roi_features)
regressor_output = self.regressor(roi_features)
return classifier_output, regressor_output, proposals
```
接下来,我们需要定义 RPN 和 RoI 池化层的前向传递函数。
```python
import torch.nn.functional as F
from torch.autograd import Variable
class RPN(nn.Module):
def __init__(self, in_channels=512, num_anchors=3):
super(RPN, self).__init__()
self.conv = nn.Conv2d(in_channels, in_channels, kernel_size=3, stride=1, padding=1)
self.cls_layer = nn.Conv2d(in_channels, num_anchors * 2, kernel_size=1, stride=1, padding=0)
self.reg_layer = nn.Conv2d(in_channels, num_anchors * 4, kernel_size=1, stride=1, padding=0)
self.anchor_scales = [8, 16, 32]
def forward(self, x):
batch_size = x.shape[0]
feature_map = self.conv(x)
cls_output = self.cls_layer(feature_map)
reg_output = self.reg_layer(feature_map)
cls_output = cls_output.permute(0, 2, 3, 1).contiguous().view(batch_size, -1, 2)
reg_output = reg_output.permute(0, 2, 3, 1).contiguous().view(batch_size, -1, 4)
return cls_output, reg_output
class RoIPool(nn.Module):
def __init__(self, output_size):
super(RoIPool, self).__init__()
self.output_size = output_size
def forward(self, features, rois):
num_rois = rois.shape[0]
output = Variable(torch.zeros(num_rois, features.shape[1], self.output_size, self.output_size))
for i in range(num_rois):
roi = rois[i]
roi_x = int(round(roi[0].item()))
roi_y = int(round(roi[1].item()))
roi_w = int(round(roi[2].item() - roi[0].item()))
roi_h = int(round(roi[3].item() - roi[1].item()))
roi_feature = features[:, :, roi_y:roi_y+roi_h, roi_x:roi_x+roi_w]
roi_feature = F.adaptive_max_pool2d(roi_feature, self.output_size)
output[i] = roi_feature
return output
```
最后,我们可以使用上述定义的模型和函数进行交通标志检测。
```python
import torch.utils.data as data
import torchvision.transforms as transforms
import torchvision.datasets as datasets
from PIL import Image
class TrafficSignDataset(data.Dataset):
def __init__(self, root):
self.root = root
self.transforms = transforms.Compose([
transforms.Resize((224, 224)),
transforms.ToTensor(),
transforms.Normalize(mean=[0.485, 0.456, 0.406],
std=[0.229, 0.224, 0.225])
])
self.img_paths = []
self.targets = []
with open(os.path.join(root, 'annotations.txt'), 'r') as f:
for line in f.readlines():
img_path, x, y, w, h, label = line.strip().split(',')
self.img_paths.append(os.path.join(root, img_path))
self.targets.append((int(x), int(y), int(w), int(h), int(label)))
def __getitem__(self, index):
img_path = self.img_paths[index]
target = self.targets[index]
img = Image.open(img_path).convert('RGB')
img = self.transforms(img)
return img, target
def __len__(self):
return len(self.img_paths)
def collate_fn(batch):
imgs = []
targets = []
for sample in batch:
imgs.append(sample[0])
targets.append(sample[1])
return torch.stack(imgs, dim=0), targets
def main():
# load dataset
dataset = TrafficSignDataset('data/')
dataloader = data.DataLoader(dataset, batch_size=4, shuffle=True, collate_fn=collate_fn)
# create model
model = FasterRCNN(num_classes=3)
model.train()
# define optimizer and loss function
optimizer = torch.optim.Adam(model.parameters(), lr=0.001)
criterion = nn.CrossEntropyLoss()
# train model
for epoch in range(10):
for images, targets in dataloader:
# move images and targets to GPU
images = images.cuda()
targets = [(torch.tensor([x, y, x+w, y+h]), label) for x, y, w, h, label in targets]
targets = [t.cuda() for t in targets]
# forward pass
classifier_output, regressor_output, proposals = model(images)
# calculate RPN loss
rpn_cls_loss, rpn_reg_loss = calculate_rpn_loss(proposals, targets)
rpn_loss = rpn_cls_loss + rpn_reg_loss
# calculate RoI loss
roi_cls_loss, roi_reg_loss = calculate_roi_loss(classifier_output, regressor_output, proposals, targets)
roi_loss = roi_cls_loss + roi_reg_loss
# calculate total loss
loss = rpn_loss + roi_loss
# backward pass
optimizer.zero_grad()
loss.backward()
optimizer.step()
print('Epoch: {} | RPN Loss: {:.4f} | RoI Loss: {:.4f} | Total Loss: {:.4f}'.format(epoch+1, rpn_loss.item(), roi_loss.item(), loss.item()))
def calculate_rpn_loss(proposals, targets):
rpn_cls_loss = 0
rpn_reg_loss = 0
for i in range(len(proposals)):
proposal = proposals[i]
target = targets[i]
# calculate IoU between proposal and target
iou = calculate_iou(proposal, target[0])
# calculate classification loss
if iou >= 0.7:
rpn_cls_loss += -torch.log(proposal[1])
elif iou < 0.3:
rpn_cls_loss += -torch.log(1 - proposal[0])
# calculate regression loss
if iou >= 0.5:
rpn_reg_loss += smooth_l1_loss(proposal[0], target[0])
return rpn_cls_loss, rpn_reg_loss
def calculate_roi_loss(classifier_output, regressor_output, proposals, targets):
roi_cls_loss = 0
roi_reg_loss = 0
for i in range(len(proposals)):
proposal = proposals[i]
target = targets[i]
# select positive and negative RoIs
positive_indices = (proposal[:, 1] > proposal[:, 0]).nonzero().flatten()
negative_indices = (proposal[:, 0] > proposal[:, 1]).nonzero().flatten()
# calculate classification loss
positive_cls_loss = -torch.log(classifier_output[i, positive_indices, target[1]])
negative_cls_loss = -torch.log(1 - classifier_output[i, negative_indices, target[1]])
roi_cls_loss += (positive_cls_loss.sum() + negative_cls_loss.sum()) / (len(positive_indices) + len(negative_indices))
# calculate regression loss
positive_reg_loss = smooth_l1_loss(regressor_output[i, positive_indices, target[1] * 4:(target[1] + 1) * 4], target[0][positive_indices])
roi_reg_loss += positive_reg_loss.sum() / len(positive_indices)
return roi_cls_loss, roi_reg_loss
def calculate_iou(box1, box2):
x1 = max(box1[0], box2[0])
y1 = max(box1[1], box2[1])
x2 = min(box1[2], box2[2])
y2 = min(box1[3], box2[3])
intersection = max(x2 - x1, 0) * max(y2 - y1, 0)
area1 = (box1[2] - box1[0]) * (box1[3] - box1[1])
area2 = (box2[2] - box2[0]) * (box2[3] - box2[1])
union = area1 + area2 - intersection
return intersection / union
def smooth_l1_loss(input, target):
diff = torch.abs(input - target)
return torch.where(diff < 1, 0.5 * diff ** 2, diff - 0.5)
if __name__ == '__main__':
main()
```
以上就是使用 Faster R-CNN 进行交通标志检测的示例代码。请注意,这只是一个简单的示例,实际应用中可能需要对代码进行修改和调整,以适应不同的数据集和应用场景。
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