Python OpenCV access webcam maximum resolution

Question

I am trying to acquire images from my webcam using a python code that imports OpenCV. The code is the following:

import sys
sys.path.append(\"C:\\\\opencv\\         


        

Answer 1

I have the same problem as you, that I cant get a higher resolution in opencv different "application". But with the Logitech Software I am able to record videos in 720p (camera C270 ). After some days of research, I came to the same explanation as @break that they restricted the resolution in the driver. I gave it up and will buy a different, non Logitech, one...

Answer 2

I used the different resolutions to set image resolution from List of common resolutions by looping over

def set_res(cap, x,y):
    cap.set(cv.CV_CAP_PROP_FRAME_WIDTH, int(x))
    cap.set(cv.CV_CAP_PROP_FRAME_HEIGHT, int(y))
    return str(cap.get(cv.CV_CAP_PROP_FRAME_WIDTH)),str(cap.get(cv.CV_CAP_PROP_FRAME_HEIGHT))

It seems that OpenCV or my camera allows only certain resolutions.

• 160.0 x 120.0

• 176.0 x 144.0

• 320.0 x 240.0

• 352.0 x 288.0

• 640.0 x 480.0

• 1024.0 x 768.0

• 1280.0 x 1024.0

Answer 3

The problem as mentioned above is caused by the camera driver. I was able to fix it using Direct Show as a backend. I read (sorry, but I do not remember where) that almost all cameras provide a driver that allows their use from DirectShow. Therefore, I used DirectShow in Windows to interact with the cameras and I was able to configure the resolution as I wanted and also get the native aspect ratio of my camera (16: 9). You can try this code to see if this works for you.

import cv2

cam = cv2.VideoCapture(0,cv2.CAP_DSHOW)

cap.set(cv2.CAP_PROP_FRAME_WIDTH, 1280)
cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 720)

r, frame = cam.read()
...
print('Resolution: ' + str(frame.shape[0]) + ' x ' + str(frame.shape[1]))

In the OpenCV documentation, I found the following information for those who want to know more about OpenCV backends (OpenCV docs)

I hope this can help you!

Answer 4

I got it to work, so this post is for others experiencing the same problem:

I am running on the Logitech C270 as well. For some reason it would only show 640x480 even though the webcam supports 1280x720. Same issue persists with the built-in webcam in my laptop.

If I set it to 800x600 in the code it shows 640x480. However, if I set it to 1024x768 it becomes 800x600. And if I set it to something silly like 2000x2000 it becomes 1280x720.

This is in C++ on OpenCV 3.0, but perhaps it applies to Python as well.

Answer 5

For cv2 just change to this.

    cap.set(cv2.CAP_PROP_FRAME_WIDTH, 800)
    cap.set(cv2.CAP_PROP_FRAME_HEIGHT, 600)

Answer 6

Try the following code to obtain the maximum camera resolution, using this you can capture your photos or video using maximum resolution:

import cv2

HIGH_VALUE = 10000
WIDTH = HIGH_VALUE
HEIGHT = HIGH_VALUE

capture = cv2.VideoCapture(0)
fourcc = cv2.VideoWriter_fourcc(*'XVID')
capture.set(cv2.CAP_PROP_FRAME_WIDTH, WIDTH)
capture.set(cv2.CAP_PROP_FRAME_HEIGHT, HEIGHT)
width = int(capture.get(cv2.CAP_PROP_FRAME_WIDTH))
height = int(capture.get(cv2.CAP_PROP_FRAME_HEIGHT))

print(width,height)