What is the data format read by the function cv2.imread? Working with tkinter and python

问题

Good day, I am quite new to Python programming and I was tasked to do my own GUI with image inside my GUI. I have been doing some good progress but i was stuck when I want to insert an image into my GUI from my webcam. However, I did manage to get an image from the webcam but it has to be a different window with the GUI window.

In my GUI codes, it includes a simple code like this:

(I use range i<25 because my webcam needs warming up)

for i in range (25):

     _ , frame = cap.read()
     frame = cv2.flip(frame, 1)
     cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)

     i+=1

     cv2.imshow("Latex Truck", cv2image)
     img = cv2image
     label = Label(root, image = img)
     label.place(x = 300, y = 300)

Now, the problem is this. I successfully obtain the frame that I need and was able to show thanks to cv2.imshow but when I try to use the same source which is the "cv2image" in tkinter, it shows this error.

Traceback (most recent call last):
  File "C:\Python34\lib\tkinter\__init__.py", line 1487, in __call__
    return self.func(*args)
  File "C:\Users\FF7_C\OneDrive\Desktop\Logo.py", line 82, in Capture
    label = Label(root, image = img)
  File "C:\Python34\lib\tkinter\__init__.py", line 2573, in __init__
    Widget.__init__(self, master, 'label', cnf, kw)
  File "C:\Python34\lib\tkinter\__init__.py", line 2091, in __init__
    (widgetName, self._w) + extra + self._options(cnf))
_tkinter.TclError: image "[[[ 49  32  22 255]

Now, logically I think I did what I needed to do which is the extract an image from the webcam which I did, the only problem now is I need to understand why tkinter cannot read the same information read by cv2.imshow.

Can someone guide me on this? Thank you very much! :)

回答1:

The format returned by cv2.cvtColor(...) is of type numpy.ndarray. You need to convert it to format recognized by tkinter by using Pillow module:

from tkinter import *
from PIL import Image, ImageTk
import cv2

root = Tk()

cap = cv2.VideoCapture(0)
ret, frame = cap.read()

img = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)
# convert to image format recognized by tkinter
img = Image.fromarray(img)
tkimg = ImageTk.PhotoImage(image=img)

Label(root, image=tkimg).pack()

root.mainloop()

来源：https://stackoverflow.com/questions/54068536/what-is-the-data-format-read-by-the-function-cv2-imread-working-with-tkinter-an

标签

python

python-3.x

user-interface

tkinter