I have only 2 USB cameras that are connected to my PC (Note: highly confident that I won’t use more than 2 cameras now and in future) . My aim of this program is to capture front and rear view concurrently. And I have successfully have the working prototype of the program which allowed to view 2 live feed video at the same time .
I attached the sample program here which allowed live video feeds from 2 cameras concurrently at the same time.
import cv2
import tkinter as tk
from datetime import datetime
from PIL import Image, ImageTk, ImageDraw
global photo1, photo2
photo1 = None
photo2 = None
def print_camera_info(width, height, camera_number):
print(f"Camera {camera_number}")
print(f"Width: {width}")
print(f"Height: {height}")
print("---")
def swap_camera():
print("In swap_camera!") #debugging purpose
global photo1, photo2
print("After define global in swap_camera") #debugging purpose
print("Before swap")#debugging purpose
# Swap the frames algorithm
tmp = photo1
photo1 = photo2
photo2 = tmp
print("After Swap") #debugging purpose
def main():
# Open two camera devices
front_cap = cv2.VideoCapture(0) # Use 0 for the first camera (Front Camera)
rear_cap = cv2.VideoCapture(1) # Use 1 for the second camera (Rear Camera)
# Check if the cameras opened successfully
if not (front_cap.isOpened() and rear_cap.isOpened()):
print("Error: Could not open cameras.")
print("front_cap opened:", front_cap.isOpened())
print("rear_cap opened:", rear_cap.isOpened())
return
# Set the desired width and height for live feed
target_width, target_height = 320, 240
# Set the CAP_PROP_FRAME_WIDTH and CAP_PROP_FRAME_HEIGHT properties for both cameras
front_cap.set(cv2.CAP_PROP_FRAME_WIDTH, target_width)
front_cap.set(cv2.CAP_PROP_FRAME_HEIGHT, target_height)
rear_cap.set(cv2.CAP_PROP_FRAME_WIDTH, target_width)
rear_cap.set(cv2.CAP_PROP_FRAME_HEIGHT, target_height)
# Get the actual dimensions after setting the properties
actual_width1 = int(front_cap.get(cv2.CAP_PROP_FRAME_WIDTH))
actual_height1 = int(front_cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
actual_width2 = int(rear_cap.get(cv2.CAP_PROP_FRAME_WIDTH))
actual_height2 = int(rear_cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
# Print camera information with the actual resized dimensions
print_camera_info(actual_width1, actual_height1, "Front")
print_camera_info(actual_width2, actual_height2, "Rear")
# Create Tkinter window
root = tk.Tk()
root.title("Combined Cameras")
# Create a Checkbutton for camera toggle
camera_toggle_button = tk.Checkbutton(root, text="Toggle Camera", command=swap_camera)
camera_toggle_button.grid(row=1, column=1, padx=10, pady=10)
# Create label widget for date and time
datetime_label = tk.Label(root, text="", font=("Helvetica", 14))
datetime_label.grid(row=1, column=2, columnspan=2, pady=10)
# Create label widgets for camera views
label1 = tk.Label(root, text="FRONT VIEW")
label2 = tk.Label(root, text="REAR VIEW")
label1.grid(row=2, column=2)
label2.grid(row=2, column=3)
# Create image labels for camera feeds
video_livefeedfront = tk.Label(root)
video_livefeedrear = tk.Label(root)
video_livefeedfront.grid(row=3, column=2, padx=10)
video_livefeedrear.grid(row=3, column=3, padx=10)
while True:
# Read frames from both cameras
ret1, frame1 = front_cap.read()
ret2, frame2 = rear_cap.read()
# Check if the frames were read successfully
if not (ret1 and ret2):
print("Error: Could not read frames from cameras.")
break
# Resize frames to the target dimensions
frame_resized1 = cv2.resize(frame1, (target_width, target_height))
frame_resized2 = cv2.resize(frame2, (target_width, target_height))
# Convert frames to RGB format for PIL
frame_rgb1 = cv2.cvtColor(frame_resized1, cv2.COLOR_BGR2RGB)
frame_rgb2 = cv2.cvtColor(frame_resized2, cv2.COLOR_BGR2RGB)
# Convert frames to PhotoImage format for Tkinter
photo1 = ImageTk.PhotoImage(Image.fromarray(frame_rgb1))
photo2 = ImageTk.PhotoImage(Image.fromarray(frame_rgb2))
# Update image live videofeed
video_livefeedfront.configure(image=photo1)
video_livefeedfront.photo = photo1
video_livefeedrear.configure(image=photo2)
video_livefeedrear.photo = photo2
# Update the Tkinter window
root.update()
# Release the camera devices and destroy the Tkinter window
front_cap.release()
rear_cap.release()
cv2.destroyAllWindows()
root.destroy()
if __name__ == "__main__":
main()
There are at times where the front and rear views might be at its designated location when connected (i.e; Front camera show rear live video feed). Therefore, I add a camera_toggle_button to swap the view . However, there are weird bugs right now, when I click on the checkbox camera_toggle_button , I expect the FRONT VIEW should be swapped with REAR VIEW , but as shown below, it does not happened at all. As you can see, I successfully print out the debugging notes (meaning it enter all the algorithm sequences correctly) , but somehow the live video feed does not swapped at all. It is weird at least. 
You need to swap the target labels instead of photo1 and photo2. Also avoid using while loop in the main thread of a tkinter application, use after loop instead.
...
def swap_camera():
global video_livefeedfront, video_livefeedrear
# swap the target labels
video_livefeedfront, video_livefeedrear = video_livefeedrear, video_livefeedfront
def main():
global video_livefeedfront, video_livefeedrear
...
# Create image labels for camera feeds
video_livefeedfront = tk.Label(root)
video_livefeedrear = tk.Label(root)
video_livefeedfront.grid(row=3, column=2, padx=10)
video_livefeedrear.grid(row=3, column=3, padx=10)
# use after loop instead of while loop
def update_cameras():
# Read frames from both cameras
ret1, frame1 = front_cap.read()
ret2, frame2 = rear_cap.read()
# Check if the frames were read successfully
if not (ret1 and ret2):
print("Error: Could not read frames from cameras.")
root.destroy()
# Resize frames to the target dimensions
frame_resized1 = cv2.resize(frame1, (target_width, target_height))
frame_resized2 = cv2.resize(frame2, (target_width, target_height))
# Convert frames to RGB format for PIL
frame_rgb1 = cv2.cvtColor(frame_resized1, cv2.COLOR_BGR2RGB)
frame_rgb2 = cv2.cvtColor(frame_resized2, cv2.COLOR_BGR2RGB)
# Convert frames to PhotoImage format for Tkinter
photo1 = ImageTk.PhotoImage(Image.fromarray(frame_rgb1))
photo2 = ImageTk.PhotoImage(Image.fromarray(frame_rgb2))
# Update image live videofeed
video_livefeedfront.configure(image=photo1)
video_livefeedfront.photo = photo1
video_livefeedrear.configure(image=photo2)
video_livefeedrear.photo = photo2
root.after(25, update_cameras) # change 25ms to whatever that suits your requirement
update_cameras() # start the after loop to update the camera feeds
root.mainloop()
# Release the camera devices and destroy the Tkinter window
front_cap.release()
rear_cap.release()
cv2.destroyAllWindows()
...
Here is the complete code. Many thanks for @acw1668
import cv2
import tkinter as tk
from datetime import datetime
from PIL import Image, ImageTk, ImageDraw
global photo1, photo2
##photo1 = None
##photo2 = None
def print_camera_info(width, height, camera_number):
print(f"Camera {camera_number}")
print(f"Width: {width}")
print(f"Height: {height}")
print("---")
def swap_camera():
print("In swap_camera functions!") #debugging purpose
global video_livefeedfront, video_livefeedrear
print("After define global in swap_camera") #debugging purpose
print("Before swap")#debugging purpose
# Swap the frames algorithm
video_livefeedfront, video_livefeedrear = video_livefeedrear, video_livefeedfront
print("After Swap") #debugging purpose
def main():
global video_livefeedfront, video_livefeedrear
# Open two camera devices
front_cap = cv2.VideoCapture(0) # Use 0 for the first camera (Front Camera)
rear_cap = cv2.VideoCapture(1) # Use 1 for the second camera (Rear Camera)
# Check if the cameras opened successfully
if not (front_cap.isOpened() and rear_cap.isOpened()):
print("Error: Could not open cameras.")
print("front_cap opened:", front_cap.isOpened())
print("rear_cap opened:", rear_cap.isOpened())
return
# Set the desired width and height for live feed
target_width, target_height = 320, 240
# Set the CAP_PROP_FRAME_WIDTH and CAP_PROP_FRAME_HEIGHT properties for both cameras
front_cap.set(cv2.CAP_PROP_FRAME_WIDTH, target_width)
front_cap.set(cv2.CAP_PROP_FRAME_HEIGHT, target_height)
rear_cap.set(cv2.CAP_PROP_FRAME_WIDTH, target_width)
rear_cap.set(cv2.CAP_PROP_FRAME_HEIGHT, target_height)
# Get the actual dimensions after setting the properties
actual_width1 = int(front_cap.get(cv2.CAP_PROP_FRAME_WIDTH))
actual_height1 = int(front_cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
actual_width2 = int(rear_cap.get(cv2.CAP_PROP_FRAME_WIDTH))
actual_height2 = int(rear_cap.get(cv2.CAP_PROP_FRAME_HEIGHT))
# Print camera information with the actual resized dimensions
print_camera_info(actual_width1, actual_height1, "Front")
print_camera_info(actual_width2, actual_height2, "Rear")
# Create Tkinter window
root = tk.Tk()
root.title("Combined Cameras")
# Create a Checkbutton for camera toggle
camera_toggle_button = tk.Checkbutton(root, text="Toggle Camera", command=swap_camera)
camera_toggle_button.grid(row=1, column=1, padx=10, pady=10)
# Create label widget for date and time
datetime_label = tk.Label(root, text="", font=("Helvetica", 14))
datetime_label.grid(row=1, column=2, columnspan=2, pady=10)
# Create label widgets for camera views
label1 = tk.Label(root, text="FRONT VIEW")
label2 = tk.Label(root, text="REAR VIEW")
label1.grid(row=2, column=2)
label2.grid(row=2, column=3)
# Create image labels for camera feeds
video_livefeedfront = tk.Label(root)
video_livefeedrear = tk.Label(root)
video_livefeedfront.grid(row=3, column=2, padx=10)
video_livefeedrear.grid(row=3, column=3, padx=10)
def update_cameras():
# Read frames from both cameras
ret1, frame1 = front_cap.read()
ret2, frame2 = rear_cap.read()
# Check if the frames were read successfully
if not (ret1 and ret2):
print("Error: Could not read frames from cameras.")
# Resize frames to the target dimensions
frame_resized1 = cv2.resize(frame1, (target_width, target_height))
frame_resized2 = cv2.resize(frame2, (target_width, target_height))
# Convert frames to RGB format for PIL
frame_rgb1 = cv2.cvtColor(frame_resized1, cv2.COLOR_BGR2RGB)
frame_rgb2 = cv2.cvtColor(frame_resized2, cv2.COLOR_BGR2RGB)
# Convert frames to PhotoImage format for Tkinter
photo1 = ImageTk.PhotoImage(Image.fromarray(frame_rgb1))
photo2 = ImageTk.PhotoImage(Image.fromarray(frame_rgb2))
# Update image live videofeed
video_livefeedfront.configure(image=photo1)
video_livefeedfront.photo = photo1
video_livefeedrear.configure(image=photo2)
video_livefeedrear.photo = photo2
root.after(25, update_cameras)
# Update the Tkinter window
#root.update()
update_cameras()
root.mainloop()
# Release the camera devices and destroy the Tkinter window
front_cap.release()
rear_cap.release()
cv2.destroyAllWindows()
root.destroy()
if __name__ == "__main__":
main()
purely a programming problem, i.e. your understanding of your own code. this may be using opencv but it’s not an opencv problem.