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Config Label In classes tkinter [duplicate]

This question already has answers here:
Tkinter: AttributeError: NoneType object has no attribute <attribute name>
(4 answers)
Closed 11 months ago.
Im trying to develop a GUI to capture images in a new window. In my work i'am trying to pass a directory of the image to be use on future functions, as of now im trying to configure a label to change its text to my image path
import tkinter as tk
from tkinter import *
import cv2
from PIL import Image, ImageTk
from tkinter.filedialog import askopenfilename
import os
from tkinter import messagebox
from pathlib import PosixPath
from numpy import result_type
class CamView():
def __init__(self, parent):
self.parent = parent
self.window = tk.Toplevel(parent)
self.lmain2 = tk.Label(self.window)
self.lmain2.pack()
self.window.protocol("WM_DELETE_WINDOW", self.close)
self.show_frame()
self.multiple()
self.btn2 = tk.Button(self.window,text="Close", command = lambda: self.close())
self.btn2.pack()
def multiple(self):
self.takePicture_button = tk.Button(self.window, text="Capture Signature",command = lambda: [Main.captureImage(self.parent),self.close()])
self.takePicture_button.pack(ipadx=5,ipady=5,pady=5)
def show_frame(self):
imgtk = ImageTk.PhotoImage(image=self.parent.img)
self.lmain2.imgtk = imgtk
self.lmain2.configure(image=imgtk)
def close(self):
self.parent.test_frame = None
self.window.destroy()
root = tk.Tk()
root.bind('<Escape>', lambda e: root.quit())
font_size = 14
window_width = 800
window_height = 400
screen_width = root.winfo_screenwidth()
screen_height = root.winfo_screenheight()
center_x = int(screen_width/2 - window_width / 2)
center_y = int(screen_height/2 - window_height / 2)
root.geometry(f'{window_width}x{window_height}+{center_x}+{center_y}')
frame_dirpath = tk.Frame(root)
frame_dirpath.pack(ipadx=5,ipady=5)
class Main(tk.Frame):
def __init__(self, parent):
self.lmain = tk.Label(parent)
self.lmain.pack()
self.test_frame = None
frame = Frame.__init__(self,parent)
a = Label(text='Verify Signatures:').pack(ipadx=5,ipady=5)
self.c = tk.Label(text = "check").pack(ipadx=5,ipady=5)
b = tk.Button(frame, text='CAMERA', command=self.load_window)
b.pack()
self.image1_path_entry = tk.Entry(frame_dirpath, font=font_size,width=25).pack(ipadx = 5, ipady = 5)
width, height = 800, 600
self.cap = cv2.VideoCapture(0)
self.cap.set(cv2.CAP_PROP_FRAME_WIDTH, width)
self.cap.set(cv2.CAP_PROP_FRAME_HEIGHT, height)
self.do_stuff()
def do_stuff(self):
_, frame = self.cap.read()
frame = cv2.flip(frame, 1)
cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)
self.img = Image.fromarray(cv2image)
if self.test_frame != None:
self.test_frame.show_frame()
self.lmain.after(10, self.do_stuff)
def captureImage(self):
image_to_write = self.cap.read()[1]
filetowrite = "D:/Downloads/c.jpeg"
print(str(filetowrite))
cv2.imwrite(str(filetowrite),image_to_write)
self.c.configure(text = filetowrite)
return
def load_window(self):
if self.test_frame == None:
self.test_frame = CamView(self)
control = Main(root)
root.mainloop()
As on the line self.c = tk.Label(text = "check").pack(ipadx=5,ipady=5) im trying to configure this label to the image path on the function when capturing an image. All i get is object is has no attribute

Changed this:
self.c = tk.Label(text = "check").pack(ipadx=5,ipady=5)
to:
self.c = tk.Label(frame, text = "check").pack(ipadx=5,ipady=5)
You did same as tk.Button(frame,

Termination Async call back error in opencv in tkinter gui

I created a master window in tkinter.... then when I press a button on master window it will open another top level window in which I created a canvas and a button....
Canvas for: reading camera frame by frame and show it in tkinter window
Button for: capture the current frame..but in button I used face detection to detect a face when it detects a face I want close the top-level window and go back master window
In master window I have another button to exit the gui(means master.destroy when I press exit) ....but here when I press exit computer is hanging and asking for force close....I am posting my code below
'''
import tkinter
from tkinter import *
import cv2
import PIL.Image, PIL.ImageTk
import time
import os
import numpy as np
class App(object):
def __init__(self,master3):
self.window=Toplevel(master3)
self.window.title("capturing image")
self.window.geometry("{}x{}".format(self.window.winfo_screenwidth(),self.window.winfo_screenheight()))
self.vid = cv2.VideoCapture(0)
#self.width = self.vid.get(cv2.CAP_PROP_FRAME_WIDTH)
#self.height = self.vid.get(cv2.CAP_PROP_FRAME_HEIGHT)
self.canvas = Canvas(self.window, width = 1000, height = 700)
self.path = os.path.dirname(os.path.abspath(__file__))
self.detector=cv2.CascadeClassifier(self.path+r'\HarrCascade\haarcascade_frontalface.xml')
#self.recognizer = cv2.face.LBPHFaceRecognizer_create()
#self.recognizer.read(self.path+r'\trained_data\trained_file.xml')
self.canvas.pack()
self.canvas.pack()
self.btn_snapshot=Button(self.window, text="Snapshot", width=50,command=self.snap)
self.btn_snapshot.pack(anchor=CENTER, expand=True)
if not self.vid.isOpened():
raise IOError("Unable to open video source")
else:
self.count=0
self.delay=15
self.update()
def g(self):
if self.vid.isOpened():
_,frame = self.vid.read()
self.frame2 = frame
self.count=1
self.vid.release()
cv2.waitKey(1)
cv2.destroyAllWindows()
for i in range(1,5):
cv2.waitKey(1)
master.deiconify()
def snap(self):
self.gray=cv2.cvtColor(self.frame2,cv2.COLOR_BGR2GRAY)
self.faces= self.detector.detectMultiScale(self.gray, scaleFactor=1.2, minNeighbors=5, minSize=(100, 100), flags=cv2.CASCADE_SCALE_IMAGE)
self.no_faces=self.faces.shape[0]
if self.no_faces >= 1:
for(x,y,w,h) in self.faces:
self.g()
cv2.imwrite("face-0.jpg",self.gray)
def update(self):
if self.vid.isOpened():
ret, frame = self.vid.read()
frame1=cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
if ret:
self.photo = PIL.ImageTk.PhotoImage(image = PIL.Image.fromarray(frame1))
self.canvas.create_image(0, 0, image = self.photo, anchor = NW)
else:
pass
if self.count==0:
self.window.after(self.delay, self.update)
else:
pass
else:
pass
def fun():
App(master)
master.withdraw()
def fun1():
master.quit()
master=Tk(screenName=None,baseName=None,className='Tk',useTk=1)
master.title('face recognition system')
master.geometry("{}x{}".format(master.winfo_screenwidth(),master.winfo_screenheight()))
button2 = Button(master,text = 'Test Image',bg = 'black',fg = 'white',font = ('algerian',10),height = 3,width = 20,command=fun)
button3 = Button(master,text = 'exit',bg = 'black',fg = 'white',font = ('algerian',10),height = 3,width = 20,command=fun1)
button2.pack()
button3.pack()
master.mainloop()
'''
thanks in advance for your kind help

Why doesn't my tkinter window show my panel?

I've got the following code:
import tkinter
import cv2
from PIL import Image, ImageTk
import threading
class HudGui:
def __init__(self, window):
# defining everything for video capture and the tkinter window
self.CapDev= cv2.VideoCapture(0)
self.cams = []
self.counter = 0
self.frame = None
self.panel = None
self.wind = window
btn = tkinter.Button(window, text="Snapshot!")
btn.pack(side="bottom", fill="both", expand="yes", padx=10, pady=10)
# defining threading for video stream
self.stopEvent = threading.Event()
self.thread = threading.Thread(target=self.videoLoop(), args=(1,))
self.thread.start()
def videoLoop(self):
while not self.stopEvent.is_set():
# reading and modifying the frame to have the proper data type
self.frame = self.CapDev.read()[1]
image = cv2.cvtColor(self.frame, cv2.COLOR_BGR2RGB)
image = Image.fromarray(image)
image = ImageTk.PhotoImage(image)
if self.panel is None:
self.panel = tkinter.Label(image=image)
self.panel.image = image
self.panel.pack(side="left") # side="left", padx=10, pady=10
# otherwise, update the panel
else:
self.panel.configure(image=image)
self.panel.image = image
hud = tkinter.Tk()
hud.title("HUD")
HudGui(hud)
hud.mainloop()
When I run this code, nothing happens. I get no window but I do know it is updating the panel (I've tested it with printing messages). Could there be permissions problem for accessing the camera and things like that?
Project info:
Python = 3.7.3
opencv-contrib-python = 3.4.4.19

Multiple Video Display using Tkinter in Python for GUI design

My task is to display a webcam stream and its black&white stream in two different frames on a single GUI using Tkinter on python. I have seen some examples on google, but they are of images not videos as in the link here. Example of image display in 2 panes on a single GUI
I need exactly the same thing but for the real time video through my webcam.

Initial question:
"I am having issues in displaying multiple (2) windows for displaying video frames in a GUI using Tkinter in python. Please help me with a
code for this task."
The initial question mentioned 2 windows so here's a basic example on how to create multiple windows with tkinter:
#import tkinter as tk
import Tkinter as tk
class MainWindow(tk.Tk):
def __init__(self, *args, **kwargs):
#super().__init__()
tk.Tk.__init__(self)
self.title("This is the MainWindow")
self._is_hidden = False
self.window1 = OtherWindow(self, title="window 1")
self.window2 = OtherWindow(self, title="window 2")
def toggle_hide(self):
if self._is_hidden:
self.iconify()
self.deiconify()
else:
self.withdraw()
self._is_hidden = not self._is_hidden
class OtherWindow(tk.Toplevel):
def __init__(self, master, *args, **kwargs):
#super().__init__(master)
tk.Toplevel.__init__(self, master)
if 'title' in kwargs:
self.title(kwargs['title'])
self.hide_main_button = tk.Button(self, text="Hide/Show MainWindow")
self.hide_main_button['command'] = self.master.toggle_hide
self.hide_main_button.pack()
if __name__ == '__main__':
root = MainWindow()
root.mainloop()

from ttk import *
import Tkinter as tk
from Tkinter import *
import cv2
from PIL import Image, ImageTk
import os
import numpy as np
global last_frame #creating global variable
last_frame = np.zeros((480, 640, 3), dtype=np.uint8)
global last_frame2 #creating global variable
last_frame2 = np.zeros((480, 640, 3), dtype=np.uint8)
global cap
cap = cv2.VideoCapture(1)
def show_vid(): #creating a function
if not cap.isOpened(): #checks for the opening of camera
print("cant open the camera")
flag, frame = cap.read()
frame = cv2.resize(frame,(400,500))
if flag is None:
print "Major error!"
elif flag:
global last_frame
last_frame = frame.copy()
global last_frame2
last_frame2 = frame.copy()
pic = cv2.cvtColor(last_frame, cv2.COLOR_BGR2RGB) #we can change the display color of the frame gray,black&white here
img = Image.fromarray(pic)
imgtk = ImageTk.PhotoImage(image=img)
lmain.imgtk = imgtk
lmain.configure(image=imgtk)
lmain.after(10, show_vid)
def show_vid2():
pic2 = cv2.cvtColor(last_frame2, cv2.COLOR_BGR2GRAY)
img2 = Image.fromarray(pic2)
img2tk = ImageTk.PhotoImage(image=img2)
lmain2.img2tk = img2tk
lmain2.configure(image=img2tk)
lmain2.after(10, show_vid2)
if __name__ == '__main__':
root=tk.Tk() #assigning root variable for Tkinter as tk
lmain = tk.Label(master=root)
lmain2 = tk.Label(master=root)
#lmain.Frame= Frame(width=768, height=576)
#framex.grid(column=3,rowspan=2,padx=5, pady=5)
lmain.pack(side = LEFT)
lmain2.pack(side = RIGHT)
root.title("Fire Alarm Detector") #you can give any title
root.geometry("900x700+100+10") #size of window , x-axis, yaxis
exitbutton = Button(root, text='Quit',fg="red",command= root.destroy).pack(side = BOTTOM,)
show_vid()
show_vid2()
root.mainloop() #keeps the application in an infinite loop so it works continuosly
cap.release()

import tkinter
import PIL.Image
import PIL.ImageTk
import cv2
class App:
def __init__(self, window, video_source1, video_source2):
self.window = window
self.window.title("KEC MEDIA PLAYER")
self.video_source1 = video_source1
self.video_source2 = video_source2
self.photo1 = ""
self.photo2 = ""
# open video source
self.vid1 = MyVideoCapture(self.video_source1, self.video_source2)
# Create a canvas that can fit the above video source size
self.canvas1 = tkinter.Canvas(window, width=500, height=500)
self.canvas2 = tkinter.Canvas(window, width=500, height=500)
self.canvas1.pack(padx=5, pady=10, side="left")
self.canvas2.pack(padx=5, pady=60, side="left")
# After it is called once, the update method will be automatically called every delay milliseconds
self.delay = 15
self.update()
self.window.mainloop()
def update(self):
# Get a frame from the video source
ret1, frame1, ret2, frame2 = self.vid1.get_frame
if ret1 and ret2:
self.photo1 = PIL.ImageTk.PhotoImage(image=PIL.Image.fromarray(frame1))
self.photo2 = PIL.ImageTk.PhotoImage(image=PIL.Image.fromarray(frame2))
self.canvas1.create_image(0, 0, image=self.photo1, anchor=tkinter.NW)
self.canvas2.create_image(0, 0, image=self.photo2, anchor=tkinter.NW)
self.window.after(self.delay, self.update)
class MyVideoCapture:
def __init__(self, video_source1, video_source2):
# Open the video source
self.vid1 = cv2.VideoCapture(video_source1)
self.vid2 = cv2.VideoCapture(video_source2)
if not self.vid1.isOpened():
raise ValueError("Unable to open video source", video_source1)
#property
def get_frame(self):
ret1 = ""
ret2 = ""
if self.vid1.isOpened() and self.vid2.isOpened():
ret1, frame1 = self.vid1.read()
ret2, frame2 = self.vid2.read()
frame1 = cv2.resize(frame1, (500, 500))
frame2 = cv2.resize(frame2, (500, 500))
if ret1 and ret2:
# Return a boolean success flag and the current frame converted to BGR
return ret1, cv2.cvtColor(frame1, cv2.COLOR_BGR2RGB), ret2, cv2.cvtColor(frame2, cv2.COLOR_BGR2RGB)
else:
return ret1, None, ret2, None
else:
return ret1, None, ret2, None
# Release the video source when the object is destroyed
def __del__(self):
if self.vid1.isOpened():
self.vid1.release()
if self.vid2.isOpened():
self.vid2.release()
def callback():
global v1,v2
v1=E1.get()
v2=E2.get()
if v1 == "" or v2 == "":
L3.pack()
return
initial.destroy()
v1 = ""
v2 = ""
initial = tkinter.Tk()
initial.title("KEC MEDIA PLAYER")
L0 = tkinter.Label(initial, text="Enter the full path")
L0.pack()
L1 = tkinter.Label(initial, text="Video 1")
L1.pack()
E1 = tkinter.Entry(initial, bd =5)
E1.pack()
L2 = tkinter.Label(initial, text="Video 2")
L2.pack()
E2 = tkinter.Entry(initial, bd =5)
E2.pack()
B = tkinter.Button(initial, text ="Next", command = callback)
B.pack()
L3 = tkinter.Label(initial, text="Enter both the names")
initial.mainloop()
# Create a window and pass it to the Application object
App(tkinter.Tk(),v1, v2)
This code works under normal circumstances but I haven't handled situations where one video ends and the other is still playing. Also, the audio has not been handled in this code.
I created two canvases in the same window and ran the video as a series of images. I have resized the video to fit a constant canvas size but you can change the canvas size to fit the video if you want.
You can change the source to be from your webcam.

python: tkinter to display video from webcam and do a QR scan

I have been trying to create a tkinter top level window that streams video form webcam and do a QR scan. I got this QR scan code from SO and another code that just updates images from webcam instead of streaming the video on a tkinter label.
and i tried to combine these both so that a toplevel window with a label updating image from webcam and a close button to close the toplevel window. And while it streams the images, it can scan for QR code and if a scan is successful, the webcam and the toplevel window gets closed.
here is what i tried.
import cv2
import cv2.cv as cv
import numpy
import zbar
import time
import threading
import Tkinter
from PIL import Image, ImageTk
class BarCodeScanner(threading.Thread, Tkinter.Toplevel):
def __init__(self):
# i made this as a global variable so i can access this image
# outside ie,. beyond the thread to update the image on to the tkinter window
global imgtk
imgtk = None
threading.Thread.__init__(self)
self.WINDOW_NAME = 'Camera'
self.CV_SYSTEM_CACHE_CNT = 5 # Cv has 5-frame cache
self.LOOP_INTERVAL_TIME = 0.2
cv.NamedWindow(self.WINDOW_NAME, cv.CV_WINDOW_NORMAL)
self.cam = cv2.VideoCapture(-1)
self.confirm = 0
def scan(self, aframe):
imgray = cv2.cvtColor(aframe, cv2.COLOR_BGR2GRAY)
# to show coloured image, as from the other code mentioned in the other code
imgcol = cv2.cvtColor(aframe, cv2.COLOR_BGR2RGBA)
imgcol_array = Image.fromarray(imgcol)
imgtk = ImageTk.PhotoImage(image=imgcol_array)
raw = str(imgray.data)
scanner = zbar.ImageScanner()
scanner.parse_config('enable')
width = int(self.cam.get(cv.CV_CAP_PROP_FRAME_WIDTH))
height = int(self.cam.get(cv.CV_CAP_PROP_FRAME_HEIGHT))
imageZbar = zbar.Image(width, height,'Y800', raw)
scanner.scan(imageZbar)
for symbol in imageZbar:
print 'decoded', symbol.type, 'symbol', '"%s"' % symbol.data
return symbol.data
def run(self):
self.datalst = []
print 'BarCodeScanner run', time.time()
while True:
for i in range(0,self.CV_SYSTEM_CACHE_CNT):
self.cam.read()
img = self.cam.read()
self.data = self.scan(img[1])
cv2.imshow(self.WINDOW_NAME, img[1])
cv.WaitKey(1)
time.sleep(self.LOOP_INTERVAL_TIME)
if self.data:
self.datalst.append(self.data)
# i have added this section so that it waits for scan
# if a scan is made it and if gets same value after 2 scans
# it has to stop webcam
if len(self.datalst) == 2 and len(set(self.datalst)) <= 1:
# I want to close the webcam before closing the toplevel window
#self.cam.release()
#cv2.destroyAllWindows()
break
self.cam.release()
def Video_Window():
video_window = Tkinter.Toplevel()
video_window.title('QR Scan !!')
img_label = Tkinter.Label(video_window)
img_label.pack(side=Tkinter.TOP)
close_button = Tkinter.Button(video_window, text='close', command = video_window.destroy)
close_button.pack(side=Tkinter.TOP)
def update_frame():
global imgtk
img_label.configure(image=imgtk)
img_label.after(10,update_frame)
update_frame()
def main():
root = Tkinter.Tk()
button_scanQr = Tkinter.Button(root, text='QR Scan', command=start_scan)
button_scanQr.pack()
root.mainloop()
def start_scan():
scanner = BarCodeScanner()
scanner.start()
Video_Window()
#scanner.join()
main()
Problem is,
I actually wanted to display the video on the Toplevel window, not the OpenCV window
at the same time do a QR Scan,if a read is sucessfull, the Toplevel window should close without abruptly closing webcam(because, when i try to use self.cam.release() or cv2.destroyAllWindows() my webcams lights or on even if i forcefully terminate the programs compilation).
Now what i get is a separate window created by OpenCV that streams video inside. But i don’t want that window, instead i want the video to be displayed on the tkinter's toplevel window. also when there is a sucessfull read, the webcam stucks at the final image it reads.
i tried to remove the line that was responsible for OpenCV window, inside the run method of BarcodeScanner class
cv2.imshow(self.WINDOW_NAME, img[1])
it still showed up with a different window with no output, and if i try to close that window, it created another one similar and recursively.
UPDATE:
As i noticed i made some silly mistakes without understanding of some lines in cv2, i made some change on the code by adding the toplevel window code into the run method of the class(im not sure if this is a right way).
import cv2
import cv2.cv as cv
import numpy
import zbar
import time
import threading
import Tkinter
from multiprocessing import Process, Queue
from Queue import Empty
from PIL import Image, ImageTk
class BarCodeScanner(threading.Thread, Tkinter.Toplevel):
def __init__(self):
threading.Thread.__init__(self)
#self.WINDOW_NAME = 'Camera'
self.CV_SYSTEM_CACHE_CNT = 5 # Cv has 5-frame cache
self.LOOP_INTERVAL_TIME = 0.2
#cv.NamedWindow(self.WINDOW_NAME, cv.CV_WINDOW_NORMAL)
self.cam = cv2.VideoCapture(-1)
# check if webcam device is free
self.proceede = self.cam.isOpened()
if not self.proceede:
return
self.confirm = 0
def scan(self, aframe):
imgray = cv2.cvtColor(aframe, cv2.COLOR_BGR2GRAY)
raw = str(imgray.data)
scanner = zbar.ImageScanner()
scanner.parse_config('enable')
width = int(self.cam.get(cv.CV_CAP_PROP_FRAME_WIDTH))
height = int(self.cam.get(cv.CV_CAP_PROP_FRAME_HEIGHT))
imageZbar = zbar.Image(width, height,'Y800', raw)
scanner.scan(imageZbar)
for symbol in imageZbar:
print 'decoded', symbol.type, 'symbol', '"%s"' % symbol.data
return symbol.data
def run(self):
if not self.proceede:
return
def show_frame():
_, img = self.cam.read()
img = cv2.flip(img,1)
cv2image = cv2.cvtColor(img, cv2.COLOR_BGR2RGBA)
img = Image.fromarray(cv2image)
imgtk = ImageTk.PhotoImage(image=img)
img_label.imgtk = imgtk
img_label.configure(image=imgtk)
video_window.after(250, show_frame)
def destroy_video_window():
self.cam.release()
video_window.destroy()
# Toplevel GUI
video_window = Tkinter.Toplevel()
video_window.title('QR Scan !!')
img_label = Tkinter.Label(video_window)
img_label.pack(side=Tkinter.TOP)
close_button = Tkinter.Button(video_window, text='close', command = destroy_video_window)
close_button.pack(side=Tkinter.RIGHT)
show_frame()
self.datalst = []
print 'BarCodeScanner run', time.time()
while True:
for i in range(0,self.CV_SYSTEM_CACHE_CNT):
self.cam.read()
img = self.cam.read()
self.data = self.scan(img[1])
time.sleep(self.LOOP_INTERVAL_TIME)
if self.data:
self.datalst.append(self.data)
if len(self.datalst) == 2 and len(set(self.datalst)) <= 1:
video_window.destroy()
break
self.cam.release()
def main():
root = Tkinter.Tk()
button_scanQr = Tkinter.Button(root, text='QR Scan', command=scaner)
button_scanQr.pack()
root.mainloop()
def scaner():
scanner = BarCodeScanner()
scanner.start()
main()
now, I can get the image on the Toplevel window, But i dont know how to close the webcam.
condition 1: when i show a QR code to scan, it reads it successfully and webcam quits without any error.
condition 2: when i click the close button on the toplevel window(say if user doesn't want to do any scan and just want to close the webcam) i get error saying
libv4l2: error dequeuing buf: Invalid argument
VIDIOC_DQBUF: Invalid argument
select: Bad file descriptor
VIDIOC_DQBUF: Bad file descriptor
select: Bad file descriptor
VIDIOC_DQBUF: Bad file descriptor
Segmentation fault (core dumped)
I am writing this application for Linux, Mac and Windows machine. How can i close or terminate the webcam safely.

Your program has two threads, the main thread and the worker thread that reads frames from the camera. When the close button is clicked, it happens in the main thread. After self.cam.release() the object self.cam is probably in an unusable state, and when a method of self.cam is called by the worker thread, there may be some trouble. Maybe the implementation of cv2.VideoCapture is faulty and it should throw some exception when that happens.
Accessing tkinter widgets from other thread than the main thread may also cause problems.
For clean program termination, creating an instance of threading.Event and then checking for event.is_set() at some point in the work thread could work. For example
def destroy_video_window():
self.stop_event.set()
video_window.destroy()
and then in the worker thread
while True:
if self.stop_event.is_set():
break
for i in range(0, self.CV_SYSTEM_CACHE_CNT):
self.cam.read()
There are several things that could be done in other way, the following is a modified version of the code. It avoids calling tkinter methods from other thread than the main thread, event_generate() being the only tkinter method called by the worker thread. Explicit polling is avoided by emitting virtual events, for example <<ScannerQuit>>, that are placed in the tkinter event queue.
import cv2
import cv2.cv as cv
import zbar
import time
import threading
import Tkinter as tk
from PIL import Image, ImageTk
class Scanner(object):
def __init__(self, handler, *args, **kw):
self.thread = threading.Thread(target=self.run)
self.handler = handler
self.CV_SYSTEM_CACHE_CNT = 5 # Cv has 5-frame cache
self.LOOP_INTERVAL_TIME = 0.2
self.cam = cv2.VideoCapture(-1)
self.scanner = zbar.ImageScanner()
self.scanner.parse_config('enable')
self.cam_width = int(self.cam.get(cv.CV_CAP_PROP_FRAME_WIDTH))
self.cam_height = int(self.cam.get(cv.CV_CAP_PROP_FRAME_HEIGHT))
self.last_symbol = None
def start(self):
self.thread.start()
def scan(self, aframe):
imgray = cv2.cvtColor(aframe, cv2.COLOR_BGR2GRAY)
raw = str(imgray.data)
image_zbar = zbar.Image(self.cam_width, self.cam_height, 'Y800', raw)
self.scanner.scan(image_zbar)
for symbol in image_zbar:
return symbol.data
def run(self):
print 'starting scanner'
while True:
if self.handler.need_stop():
break
# explanation for this in
# http://stackoverflow.com/a/35283646/5781248
for i in range(0, self.CV_SYSTEM_CACHE_CNT):
self.cam.read()
img = self.cam.read()
self.handler.send_frame(img)
self.data = self.scan(img[1])
if self.handler.need_stop():
break
if self.data is not None and (self.last_symbol is None
or self.last_symbol <> self.data):
# print 'decoded', symbol.type, 'symbol', '"%s"' % symbol.data
self.handler.send_symbol(self.data)
self.last_symbol = self.data
time.sleep(self.LOOP_INTERVAL_TIME)
self.cam.release()
class ScanWindow(tk.Toplevel):
def __init__(self, parent, gui, *args, **kw):
tk.Toplevel.__init__(self, master=parent, *args, **kw)
self.parent = parent
self.gui = gui
self.scanner = None
self.lock = threading.Lock()
self.stop_event = threading.Event()
self.img_label = tk.Label(self)
self.img_label.pack(side=tk.TOP)
self.close_button = tk.Button(self, text='close', command=self._stop)
self.close_button.pack()
self.bind('<Escape>', self._stop)
parent.bind('<<ScannerFrame>>', self.on_frame)
parent.bind('<<ScannerEnd>>', self.quit)
parent.bind('<<ScannerSymbol>>', self.on_symbol)
def start(self):
self.frames = []
self.symbols = []
class Handler(object):
def need_stop(self_):
return self.stop_event.is_set()
def send_frame(self_, frame):
self.lock.acquire(True)
self.frames.append(frame)
self.lock.release()
self.parent.event_generate('<<ScannerFrame>>', when='tail')
def send_symbol(self_, data):
self.lock.acquire(True)
self.symbols.append(data)
self.lock.release()
self.parent.event_generate('<<ScannerSymbol>>', when='tail')
self.stop_event.clear()
self.scanner = Scanner(Handler())
self.scanner.start()
self.deiconify()
def _stop(self, *args):
self.gui.stop()
def stop(self):
if self.scanner is None:
return
self.stop_event.set()
self.frames = []
self.symbols = []
self.scanner = None
self.iconify()
def quit(self, *args):
self.parent.event_generate('<<ScannerQuit>>', when='tail')
def on_symbol(self, *args):
self.lock.acquire(True)
symbol_data = self.symbols.pop(0)
self.lock.release()
print 'symbol', '"%s"' % symbol_data
self.after(500, self.quit)
def on_frame(self, *args):
self.lock.acquire(True)
frame = self.frames.pop(0)
self.lock.release()
_, img = frame
img = cv2.flip(img, 1)
cv2image = cv2.cvtColor(img, cv2.COLOR_BGR2RGBA)
img = Image.fromarray(cv2image)
imgtk = ImageTk.PhotoImage(image=img)
self.img_label.imgtk = imgtk
self.img_label.configure(image=imgtk)
class GUI(object):
def __init__(self, root):
self.root = root
self.scan_window = ScanWindow(self.root, self)
self.scan_window.iconify()
self.root.title('QR Scan !!')
self.lframe = tk.Frame(self.root)
self.lframe.pack(side=tk.TOP)
self.start_button = tk.Button(self.lframe, text='start', command=self.start)
self.start_button.pack(side=tk.LEFT)
self.stop_button = tk.Button(self.lframe, text='stop', command=self.stop)
self.stop_button.configure(state='disabled')
self.stop_button.pack(side=tk.LEFT)
self.close_button = tk.Button(self.root, text='close', command=self.quit)
self.close_button.pack(side=tk.TOP)
self.root.bind('<<ScannerQuit>>', self.stop)
self.root.bind('<Control-s>', self.start)
self.root.bind('<Control-q>', self.quit)
self.root.protocol('WM_DELETE_WINDOW', self.quit)
def start(self, *args):
self.start_button.configure(state='disabled')
self.scan_window.start()
self.stop_button.configure(state='active')
def stop(self, *args):
self.scan_window.stop()
self.start_button.configure(state='active')
self.stop_button.configure(state='disabled')
def quit(self, *args):
self.scan_window.stop()
self.root.destroy()
def main():
root = tk.Tk()
gui = GUI(root)
root.mainloop()
main()