Question

When i run my python code i get the following error...

C: \Users \bucca\Desktop\FaceRec>python camera_recognition2.py Traceback (most recent call last): File "camera_recognition2.py", line 92, in <module> cv2.imshow( 'Video', frame) cv2.error: OpenCV(3.4.3) C:\projects\opencv-python\opencvlmodules \highgui\src\window.cpp:632: error: (-2:Unspecified er or) The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Carbon support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script in function 'cvShowImage'

and im not sure how to fix the error, can someone help me?

____________________Hers my Code__________________

import face_recognition
import cv2

# Get a reference to your webcam
video_capture = cv2.VideoCapture(0)

# Load a sample picture of yourself and learn how to recognize it.
kyle_image = face_recognition.load_image_file("kyle.jpg")
kyle_face_encoding = face_recognition.face_encodings(kyle_image)[0]

# Load a second sample picture and learn how to recognize it.
##lauren_image = face_recognition.load_image_file("lauren.jpg")
##lauren_face_encoding = face_recognition.face_encodings(lauren_image)[0]

# Load a third sample picture and learn how to recognize it.
##costa_image = face_recognition.load_image_file("costa.jpg")
##costa_face_encoding = face_recognition.face_encodings(costa_image)[0]

# Load a fourth sample picture and learn how to recognize it.
##michael_image = face_recognition.load_image_file("michael.jpg")
##michael_face_encoding = face_recognition.face_encodings(michael_image)[0]

# Create arrays of known face encodings and their names
known_face_encodings = [
    kyle_face_encoding,
    ##lauren_face_encoding,
    ##costa_face_encoding,
    ##michael_face_encoding
]
known_face_names = [
    "Kyle Horton",
    ##"Lauren Ritchie",
    ##"Costa Ciminiello",
    ##"Michael McBride"
]

# Initialize some variables
face_locations = []
face_encodings = []
face_names = []
process_this_frame = True

while True:
    # Grab a frame of the video
    ret, frame = video_capture.read()

    # Resize frame of video to smaller size for faster processing
    small_frame = cv2.resize(frame, (0, 0), fx=0.25, fy=0.25)

    # Convert the image from BGR color (which OpenCV uses) to RGB color (which face_recognition uses)
    rgb_small_frame = small_frame[:, :, ::-1]

    # Only process every other frame of video to save time
    if process_this_frame:
        # Find all the faces and face encodings in the current frame of video
        face_locations = face_recognition.face_locations(rgb_small_frame)
        face_encodings = face_recognition.face_encodings(rgb_small_frame, face_locations)

        face_names = []
        for face_encoding in face_encodings:
            # See if the face is a match for the known face(s)
            matches = face_recognition.compare_faces(known_face_encodings, face_encoding)
            name = "Unknown"

            # If a match was found in known_face_encodings, just use the first one.
            if True in matches:
                first_match_index = matches.index(True)
                name = known_face_names[first_match_index]

            face_names.append(name)

    process_this_frame = not process_this_frame

    # Display the results
    for (top, right, bottom, left), name in zip(face_locations, face_names):
        # Scale back up face locations since the frame we detected in was scaled to 1/4 size
        top *= 4
        right *= 4
        bottom *= 4
        left *= 4

        # Draw a box around the face
        cv2.rectangle(frame, (left, top), (right, bottom), (0, 0, 255), 2)

        # Draw a label with a name below the face
        cv2.rectangle(frame, (left, bottom - 35), (right, bottom), (0, 0, 255), cv2.FILLED)
        font = cv2.FONT_HERSHEY_DUPLEX
        cv2.putText(frame, name, (left + 6, bottom - 6), font, 1.0, (255, 255, 255), 1)

    # Display the resulting image
    cv2.imshow('Video', frame)

    # Hit 'q' on the keyboard to quit!
    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

# Release handle to the webcam
video_capture.release()
cv2.destroyAllWindows()

Answer 1

On which OS you get this error? The error appears because OpenCV provided by this repo has not been built with GTK support
OpenCV needs to be compiled with GTK support (WITH_GTK=ON).

There are 3 possibilites to go about this:
1. If you have Anaconda installed, and your OpenCV does not support GTK+ (as in this case), you can simply type

conda remove opencv
conda update conda
conda install --channel menpo opencv

or (for OpenCV 3.1) :

conda install -c menpo opencv3

2. you can try to use matplotlib .

import cv2
import matplotlib.pyplot as plt

img = cv2.imread('img.jpg',0)

plt.imshow(img, cmap='gray')
plt.show()

3. build library by your own with option WITH_GTK=ON