### 使用 Python 和 OpenCV 实现基于人体移动触发拍照 #### 初始化环境设置 为了实现这一功能，首先需要安装必要的库。可以使用 `pip` 安装这些依赖项： ```bash pip install opencv-python numpy imutils ``` #### 创建运动检测器类 创建一个名为 `MotionDetector` 的类用于处理视频流并识别其中的动作变化。 ```python import cv2 import datetime class MotionDetector: def __init__(self, video_source=0): self.video = cv2.VideoCapture(video_source) _, frame = self.video.read() gray_frame = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) gray_frame = cv2.GaussianBlur(gray_frame, (21, 21), 0) self.avg_frame = gray_frame.copy().astype("float") def detect_motion(self): ret, frame = self.video.read() if not ret: return False text = "Unoccupied" # Convert the current frame to grayscale and blur it gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) gray = cv2.GaussianBlur(gray, (21, 21), 0) # Accumulate the weighted average between the current frames, # then compute the difference between the current frame and running average. cv2.accumulateWeighted(gray, self.avg_frame, 0.5) frame_delta = cv2.absdiff(gray, cv2.convertScaleAbs(self.avg_frame)) thresh = cv2.threshold(frame_delta, 25, 255, cv2.THRESH_BINARY)[1] thresh = cv2.dilate(thresh, None, iterations=2) contours, _ = cv2.findContours(thresh.copy(), cv2.RETR_EXTERNAL, cv2.CHAIN_APPROX_SIMPLE) for contour in contours: if cv2.contourArea(contour) < 500: continue (x, y, w, h) = cv2.boundingRect(contour) cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 255, 0), 2) text = "Occupied" if text == "Occupied": timestamp = datetime.datetime.now() filename = f"{timestamp.strftime('%Y%m%d_%H%M%S')}.jpg" cv2.imwrite(filename, frame) cv2.putText(frame, f"Status: {text}", (10, 20), cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 0, 255), 2) return True def release(self): self.video.release() ``` 此代码片段定义了一个简单的动作捕捉机制[^1]。每当检测到显著的变化时就会保存图像文件，并带有时间戳标记。 #### 主程序逻辑 最后，在主函数中实例化上述类对象，并持续调用其方法直到按下 'q' 键退出循环。 ```python if __name__ == "__main__": detector = MotionDetector() while True: motion_detected = detector.detect_motion() key = cv2.waitKey(1) & 0xFF if key == ord('q'): break detector.release() cv2.destroyAllWindows() ``` 这段脚本会打开默认摄像头设备（或指定其他输入源），实时监控画面中的任何变动情况；一旦发现有物体进入视野范围内即刻拍摄照片存档。