opencv获取摄像头的最大分辨率图像

事情是这样的，在拼多多花了40买了一个4k高清的摄像偷，确实清楚。但是我一直以为网络摄像头分辨率只有640*480,于是用python测试了一下，上代码

import cv2def get_max_resolution(camera_index):"""获取摄像头的最大分辨率。"""cap = cv2.VideoCapture(camera_index)if not cap.isOpened():return None, Nonemax_width, max_height = 0, 0# 定义常见分辨率列表resolutions = [(640, 480),(1280, 720),(1920, 1080),(2560, 1440),(3840, 2160)]for width, height in resolutions:cap.set(cv2.CAP_PROP_FRAME_WIDTH, width)cap.set(cv2.CAP_PROP_FRAME_HEIGHT, height)actual_width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))actual_height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))if actual_width == width and actual_height == height:max_width, max_height = actual_width, actual_heightcap.release()return max_width, max_heightdef find_all_cameras(max_index=10):"""遍历所有可用的摄像头并输出最大分辨率。"""cameras = []for camera_index in range(max_index):cap = cv2.VideoCapture(camera_index)if cap.isOpened():cameras.append(camera_index)cap.release()print(f"发现 {len(cameras)} 个摄像头：")for camera in cameras:max_width, max_height = get_max_resolution(camera)if max_width and max_height:print(f"摄像头 {camera} 的最大分辨率为：{max_width}x{max_height}")else:print(f"摄像头 {camera} 无法获取分辨率")def capture_image_with_maximized_window(camera_index, width, height):"""采集摄像头图像并以最大化窗口显示。"""cap = cv2.VideoCapture(camera_index)if not cap.isOpened():print(f"无法打开摄像头 {camera_index}")return# 设置摄像头分辨率cap.set(cv2.CAP_PROP_FRAME_WIDTH, width)cap.set(cv2.CAP_PROP_FRAME_HEIGHT, height)actual_width = int(cap.get(cv2.CAP_PROP_FRAME_WIDTH))actual_height = int(cap.get(cv2.CAP_PROP_FRAME_HEIGHT))print(f"实际采集的图像分辨率: 宽度={actual_width}, 高度={actual_height}")ret, frame = cap.read()if ret:# 创建窗口并最大化cv2.namedWindow("Captured Frame", cv2.WINDOW_NORMAL)cv2.resizeWindow("Captured Frame", 1920, 1080)  # 设置默认分辨率窗口大小cv2.imshow("Captured Frame", frame)# 保存图像到本地cv2.imwrite("captured_image.jpg", frame)print("图像已保存为 'captured_image.jpg'")else:print("无法采集图像")# 等待按键退出cv2.waitKey(0)cap.release()cv2.destroyAllWindows()if __name__ == "__main__":# 遍历所有摄像头并输出最大分辨率find_all_cameras()# 示例：采集第一个摄像头的图像camera_index = 0capture_width = 1920capture_height = 1080capture_image_with_maximized_window(camera_index, capture_width, capture_height)

输出为：发现 2 个摄像头：
摄像头 0 的最大分辨率为：1920x1080
摄像头 2 的最大分辨率为：1920x1080
实际采集的图像分辨率: 宽度=1920, 高度=1080

买了2个摄像头，一个2K,一个4k实际都是2k吧，请问另外的2k哪里去了