New to Python, help with saving image from camera

[tantony]

I'm new to Python, but I decided to write a program that takes a picture of a person's face and saves it as "who.jpg". When I run this code, I'm able to see the camera and rectangles around the face, but the "who.jpg" is blank, and it's 0 kb in size. What can I do to have the "who.jpg" take picture of the face and save it? I just need to take the picture of the face one time.

import cv2
import sys

cascPath = 'haarcascade_frontalface_default.xml'
faceCascade = cv2.CascadeClassifier(cascPath)

video_capture = cv2.VideoCapture('rtsp://ituser:[email protected]/mpeg4/media.amp')

while True:
    # Capture frame-by-frame
    ret, frame = video_capture.read()

    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)

    faces = faceCascade.detectMultiScale(
        gray,
        scaleFactor=1.1,
        minNeighbors=5,
        minSize=(30, 30)
    )

    # Draw a rectangle around the faces
    for (x, y, w, h) in faces:
        cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 255, 0), 2)

    # Display the resulting frame
    img = cv2.imshow('Server Room', frame)
    cv2.imwrite("who.jpg", img)

    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# When everything is done, release the capture
video_capture.release()
cv2.destroyAllWindows()

Thanks,

Tony

---

I guess I can't use imread for videos, and this says I need to use ffmpeg. Am I correct?

https://stackoverflow.com/questions/3726...ng-a-video

[ThomasL]

The cv2.imwrite("who.jpg", img) is inside the loop, so every img shown on the screen
is written into that filename. I don´t think that is what you want and i assume the code can´t write that fast.
In addition cv2.imwrite() returns an integer, if i´m not wrong 0 means ok, 1 means error.

Untested and only an idea:

    # Display the resulting frame
    img = cv2.imshow('Server Room', frame)
 
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break
    if cv2.waitKey(1) & 0xFF == ord('p'):
        err = cv2.imwrite("who.jpg", img)
        print(error)
        break

Should save an image if you press p key and then quit.

[tantony]

I got it figured it out, and its working now! Thanks everybody for the help.

""" Importing libraries """

import cv2
import datetime
import os

""" Declaring variables """

cascPath = 'haarcascade_frontalface_default.xml'
faceCascade = cv2.CascadeClassifier(cascPath)
camera = cv2.VideoCapture('rtsp://ituser:[email protected]/mpeg4/media.amp')
path = './Images'

""" Do this while the camera is working """

while (camera.isOpened()):
    ret, frame = camera.read()
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    faces = faceCascade.detectMultiScale(
        gray,
        scaleFactor=1.2,
        minNeighbors=5,
        minSize=(30, 30)
    )

    for (x, y, w, h) in faces:
        cv2.rectangle(frame, (x, y), (x + w, y + h), (0, 255, 255), 2)
        date = datetime.datetime.now()
        date = (date.strftime("%m-%d-%Y_%H%M%S"))
        jpeg = date + '.jpg'
        cv2.imwrite(os.path.join(path,jpeg), frame)

    cv2.imshow('SCA Server Room', frame)

    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

""" Finally, release the capture and close windows """

camera.release()
cv2.destroyAllWindows()