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Python中基于SSDMobileNetV1FeatureExtractor()的目标检测模型性能评估

发布时间:2024-01-15 06:51:40

在Python中,使用TensorFlow Object Detection API中的SSDMobileNetV1FeatureExtractor()进行目标检测模型的性能评估,可以通过以下步骤进行操作:

1. 导入必要的库:

import os
import numpy as np
import tensorflow as tf
from object_detection.utils import ops as utils_ops
from object_detection.utils import label_map_util
from object_detection.utils import visualization_utils as vis_util

2. 定义一些必要的变量:

model_name = 'ssd_mobilenet_v1_coco_2018_01_28'  # 模型名称
path_to_model = os.path.join('pre-trained-models', model_name, 'frozen_inference_graph.pb')
path_to_labels = os.path.join('data', 'mscoco_label_map.pbtxt')
num_classes = 90  # 类别数量

3. 加载训练好的模型和标签映射文件:

detection_graph = tf.Graph()
with detection_graph.as_default():
    od_graph_def = tf.GraphDef()
    with tf.gfile.GFile(path_to_model, 'rb') as fid:
        serialized_graph = fid.read()
        od_graph_def.ParseFromString(serialized_graph)
        tf.import_graph_def(od_graph_def, name='')
label_map = label_map_util.load_labelmap(path_to_labels)
categories = label_map_util.convert_label_map_to_categories(label_map, max_num_classes=num_classes, use_display_name=True)
category_index = label_map_util.create_category_index(categories)

4. 加载测试图像并进行目标检测:

def load_image_into_numpy_array(image):
    (im_width, im_height) = image.size
    return np.array(image.getdata()).reshape((im_height, im_width, 3)).astype(np.uint8)

def run_inference_for_single_image(image, graph):
    with graph.as_default():
        with tf.Session() as sess:
            ops = tf.get_default_graph().get_operations()
            all_tensor_names = {output.name for op in ops for output in op.outputs}
            tensor_dict = {}
            for key in [
                'num_detections', 'detection_boxes', 'detection_scores',
                'detection_classes', 'detection_masks'
            ]:
                tensor_name = key + ':0'
                if tensor_name in all_tensor_names:
                    tensor_dict[key] = tf.get_default_graph().get_tensor_by_name(tensor_name)
            if 'detection_masks' in tensor_dict:
                detection_boxes = tf.squeeze(tensor_dict['detection_boxes'], [0])
                detection_masks = tf.squeeze(tensor_dict['detection_masks'], [0])

            image_tensor = tf.get_default_graph().get_tensor_by_name('image_tensor:0')
            output_dict = sess.run(tensor_dict,
                                   feed_dict={image_tensor: np.expand_dims(image, 0)})

            num_detections = int(output_dict['num_detections'][0])
            detection_boxes = output_dict['detection_boxes'][0][:num_detections]
            detection_scores = output_dict['detection_scores'][0][:num_detections]
            detection_classes = output_dict['detection_classes'][0][:num_detections]

    return num_detections, detection_boxes, detection_scores, detection_classes

# 载入测试图像
image_path = 'test.jpg'
image = Image.open(image_path)
image_np = load_image_into_numpy_array(image)

# 进行目标检测
output_dict = run_inference_for_single_image(image_np, detection_graph)

5. 可视化检测结果:

vis_util.visualize_boxes_and_labels_on_image_array(
    image_np,
    output_dict['detection_boxes'],
    output_dict['detection_classes'],
    output_dict['detection_scores'],
    category_index,
    instance_masks=output_dict.get('detection_masks'),
    use_normalized_coordinates=True,
    line_thickness=8)

plt.imshow(image_np)
plt.show()

这样,您就可以使用SSDMobileNetV1FeatureExtractor()对目标检测模型进行性能评估,并在图像上可视化检测结果了。注意,需要提前下载相应的预训练模型和标签文件,并将其放在正确的路径下。