opencv - OpenCV-跟踪栏不会出现-窗口不会调整大小

Question

这是我的代码，窗口似乎没有调整大小或显示任何轨迹栏。这只是显示一个空白窗口。

import cv2

def empty(a):
    pass

cv2.namedWindow("Trackbars")
cv2.resizeWindow("Trackbars",640,300)
cv2.createTrackbar("Hue Min","Trackbars",0,179,empty)
cv2.createTrackbar("Hue Max","Trackbars",179,179,empty)
cv2.createTrackbar("Sat Min","Trackbars",0,255,empty)
cv2.createTrackbar("Sat Max","Trackbars",255,255,empty)
cv2.createTrackbar("Val Min","Trackbars",0,255,empty)
cv2.createTrackbar("Val Max","Trackbars",255,255,empty)

Answer 1

根据Python中的namedWindow API:

Python:
    None = cv.namedWindow( winname[, flags] )

您应该将 cv2.WINDOW_NORMAL 作为标志参数传递，它使您能够调整窗口的大小。

提醒您，没有循环就不会看到该窗口，因为创建窗口后它将立即退出。我建议您在代码末尾添加类似于 waitKey 的循环。

这是用于演示的修改后的代码:

import cv2

def empty(a):
    pass

cv2.namedWindow("Trackbars", cv2.WINDOW_NORMAL)
cv2.resizeWindow("Trackbars",640,300)
cv2.createTrackbar("Hue Min","Trackbars",0,179,empty)
cv2.createTrackbar("Hue Max","Trackbars",179,179,empty)
cv2.createTrackbar("Sat Min","Trackbars",0,255,empty)
cv2.createTrackbar("Sat Max","Trackbars",255,255,empty)
cv2.createTrackbar("Val Min","Trackbars",0,255,empty)
cv2.createTrackbar("Val Max","Trackbars",255,255,empty)

ch = None
while ch != 27:
    ch = cv2.waitKey(0)