How To Connect A Usb Camera To Raspberry Pi

Working with USB webcams on your Raspberry Pi

In nigh cases it is best to use a Raspberry Pi camera module. Nonetheless, to help y'all with those cases you nevertheless desire to use a USB webcam, follow the below guide.

Table of contents

1. Pros and cons of a USB webcam
2. Setting upwards and using a USB webcam
3. Decision-making the webcam with Python
4. Setting up multiple USB webcams

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Pros and cons of a USB webcam

USB Webcams generally take inferior quality to the camera modules that connect to the CSI interface. They tin also non be controlled using the raspistill and rasivid commands in the terminal neither past the picamera recording package in Python. Nevertheless, at that place may exist reasons why you lot desire to connect a USB camera to your Raspberry Pi, such as because of the benefit that it is much easier to set upward multiple camera's with a single Raspberry Pi (run into below).

Setting up and using a USB webcam

You can command a USB webcam both using bash in the terminal and with Python. First plugin the camera and run into if the Raspberry Pi recognises it by entering lsusb in the terminal. It should testify something similar this:

To command the camera in the terminal I advise to use the fswebcam package. To install:

            sudo apt install fswebcam                      

To take an image with a certain resolution and hide the standard imprint:

            fswebcam -r 1280x720 --no-banner /images/image1.jpg                      

To find the supported webcam resolutions:

            v4l2-ctl --listing-formats-ext                      

You could besides use ffmpeg to take images and video. To install:

To take an epitome:

            ffmpeg -f v4l2 -video_size 1280x720 -i /dev/video0 -frames i out.jpg                      

A more advanced alternative is mjpeg-streamer, which enables you to stream the photographic camera in a browser. You can find a detailed tutorial how to set that up here.

Controlling the webcam with Python

A number of solutions exist to connect to the USB camera with Python. Unfortunately the picamera software does non work with USB webcams. I advise to use OpenCV. To help install OpenCV, follow my guide hither. Now to record a single image:

            import cv2  cam = cv2.VideoCapture(0)  while True: 	ret, image = cam.read() 	cv2.imshow('Imagetest',image) 	k = cv2.waitKey(ane) 	if one thousand != -1: 		pause cv2.imwrite('/home/pi/testimage.jpg', paradigm) cam.release() cv2.destroyAllWindows()                      

There are many other options available with opencv. I suggest to read the documentation at opencv.org.

Setting up multiple USB webcams

You lot can connect as many webcams as you lot desire as long every bit they are powered up per their requirements, such as using a powered USB hub. Each usb web cam that y'all connect gets listed under /dev/video<n> where n, starting at 0 for camera i, is the id of the device.

To list your devices:

You can set the device to employ for recordings with the fswebcam software with the --device flag. For example, to accept an image with the second connected USB webcam using fswebcam:

            fswebcam --device /dev/video1 image.jpg                      

And with Python and OpenCV y'all tin just set up cv2.VideoCapture to 1.

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Source: https://raspberrypi-guide.github.io/electronics/using-usb-webcams

Posted by: dominytellost.blogspot.com

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