等效于 function 到 openCV Python 中的 input()

Question

I have written a small application in which a user clicks regions of an image to label, then labels that region of the image with a string. I use openCV's onMouseCallback() to manage the clicks, and I read strings in using the input() function. However, this is a less-than-desirable solution because the user must click to the console, type the string into the console, press enter, and then click back to the image window, for each labeling string.

Is there a function in OpenCV that would allow for inputting a string without ever clicking away from the openCV window, essentially analogous to the input() function?

One could probably achieve this result by defining a series of keystroke handlers, but this would be somewhat tedious to implement.

Answer 1

I came up with a fairly simple solution, but I figured I'd post it here rather than deleting my question because I couldn't find this solution elsewhere on SE or online. This doesn't currently work for special characters:

import string    

def keyboard_input():
    text = ""
    letters = string.ascii_lowercase + string.digits
    while True:
        key = cv2.waitKey(1)
        for letter in letters:
            if key == ord(letter):
                text = text + letter
        if key == ord("\n") or key == ord("\r"): # Enter Key
            break
    return text