Opencv does not recognize a usb camera

Question

I have a problem with Opencv and Python. When I try to see frames from camera it does not to recognize a usb camera, I have used standar code from books with two usb cameras, the problem is that only one camera works and I do not know. I run opencv with python on windows, the camera's drivers are installed because Windows recognizes it. Whats it´s wrong with second camera? Thanks

Answer 1

of course! The code is following:

import cv2
import Tkinter as tk
from PIL import Image, ImageTk

#Set up GUI
window = tk.Tk()  #Makes main window
window.wm_title("Digital Microscope")
window.config(background="#FFFFFF")

#Graphics window
imageFrame = tk.Frame(window, width=600, height=500)
imageFrame.grid(row=0, column=0, padx=10, pady=2)

#Capture video frames
lmain = tk.Label(imageFrame)
lmain.grid(row=0, column=0)
cap = cv2.VideoCapture(0)
def show_frame():
    _, frame = cap.read()
    frame = cv2.flip(frame, 1)
    cv2image = cv2.cvtColor(frame, cv2.COLOR_BGR2RGBA)
    img = Image.fromarray(cv2image)
    imgtk = ImageTk.PhotoImage(image=img)
    lmain.imgtk = imgtk
    lmain.configure(image=imgtk)
    lmain.after(10, show_frame) 

show_frame()  #Display 2
window.mainloop()  #Starts GUI

I don't exactly remember where I copy this code, I think from here, stackoverflow. Thanks