python - 使用python mss在屏幕记录顶部绘制边框

我有要进行屏幕记录的代码，每帧我都有一组要在每帧上显示的边界框。我可以使用matplotlib或其他方式执行此操作，但mss的工作速度约为30fps，因此我需要能够快速显示边界框。

我在this example文档中注意到了，但是我尝试运行它，但无法显示任何内容。而且我甚至不确定这是否适用于我的示例。

import cv2
import time
import numpy as np
from mss import mss

with mss() as sct:
        # Part of the screen to capture
        monitor = {"top": 79, "left": 265, "width": 905, "height": 586}

        while "Screen capturing":
            last_time = time.time()

            # Get raw pixels from the screen, save it to a Numpy array
            screen = np.array(sct.grab(monitor))

            # print("fps: {}".format(1 / (time.time() - last_time)))

            print('loop took {} seconds'.format(time.time()-last_time))
            last_time = time.time()
            screen = cv2.cvtColor(screen, cv2.COLOR_BGR2RGB)
            screen = cv2.resize(screen, (224,224)).astype(np.float32)/255

            # Display the picture
            cv2.imshow("OpenCV/Numpy normal", screen)

            # Press "q" to quit
            if cv2.waitKey(25) & 0xFF == ord("q"):
                cv2.destroyAllWindows()
                break

现在说我有一组边框要显示在每个帧上，例如，

bboxes = [np.array([12, 16, 29, 25]), np.array([5,  5, 38, 35])]

我可以以某种方式更改像素以显示此像素吗？我想我也可以通过opencv来做到这一点，因为这最终将显示在屏幕上。

编辑:关于边界框的注释，它们是x1, y1, width, height，并且在调整后的(224,224)图像中

最佳答案

有一些遗漏的细节:

边框的格式是什么:[x1, y1, x2, y2]或[x1, y1, width, height]或其他？

边界框值是在调整大小(224, 224)还是原始范围内？

无论如何，您可以使用下面的函数绘制矩形(您需要根据格式进行选择):

def draw_bboxes(img, bboxes, color=(0, 0, 255), thickness=1):
    for bbox in bboxes:
        # if [x1, y1, x2, y2]
        cv2.rectangle(img, tuple(bbox[:2]), tuple(bbox[-2:]), color, thickness)
        # if [x1, y1, width, height]
        cv2.rectangle(img, tuple(bbox[:2]), tuple(bbox[:2]+bbox[-2:]), color, thickness)

假设您定义了bboxes，则可以调用以下函数:

如果要在原始框架上绘制:

# [...]
screen = np.array(sct.grab(monitor))
draw_bboxes(screen, bboxes)
# [...]

如果要在调整大小的框架上绘制:

# [...]
screen = cv2.resize(screen, (224,224)).astype(np.float32)/255
draw_bboxes(screen, bboxes)
# [...]

进行一些更改后，完整代码将如下所示:

import cv2
import time
import numpy as np
from mss import mss

def draw_bboxes(img, bboxes, color=(0, 0, 255), thickness=1):
    for bbox in bboxes:
        cv2.rectangle(img, tuple(bbox[:2]), tuple(bbox[:2]+bbox[-2:]), color, thickness)

# bounding boxes
bboxes = [np.array([12, 16, 29, 25]), np.array([5,  5, 38, 35])]

with mss() as sct:
    # part of the screen to capture
    monitor = {"top": 79, "left": 265, "width": 905, "height": 586}
    while "Screen capturing":
        # get screen
        last_time = time.time()
        screen = np.asarray(sct.grab(monitor))
        print('loop took {} seconds'.format(time.time()-last_time))

        # convert from BGRA --> BGR
        screen = cv2.cvtColor(screen, cv2.COLOR_BGRA2BGR)
        # resize and draw bboxes
        screen = cv2.resize(screen, (224,224))
        draw_bboxes(screen, bboxes)

        # display
        cv2.imshow("OpenCV/Numpy normal", screen)

        # Press "q" to quit
        if cv2.waitKey(25) & 0xFF == ord("q"):
            cv2.destroyAllWindows()
            break

输出将是这样的:

关于python - 使用python mss在屏幕记录顶部绘制边框，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/54296285/