Open CV running error

Hi, I’m trying to run this code but I’m getting this error. Please help

while True:
    ret,frame = cap.read()
    #eye_cascade = cv2.CascadeClassifier(cv2.data.haarcascades + 'haarcascade_eye.xml')
    faceCascade = cv2.CascadeClassifier(cv2.data.haarcascades + 'haarcascade_frontalface_default.xml')
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    #print(faceCascade.empty())
    faces = faceCascade.detectMultiScale(gray,1.1,4)
    for x,y,w,h in faces:
        roi_gray = gray[y:y+h, x:x+w]
        roi_color = frame[y:y+h, x:x+w]
        cv2.rectangle(frame, (x,y), (x+w, y+h), (255,0,0), 2)
        facess = faceCascade.detectMultiScale(roi_gray)
        if len(facess) == 0:
            print("Face not detected")
        else: 
            for (ex,ey,ew,eh) in facess:
                face_roi = roi_color[ey: ey+eh, ex:ex + ew]
    #error face_roi not defined 
    final_image = cv2.resize(face_roi, (224,224))
    final_image = np.expand_dims(final_image,axis=0) ## needed fourth dimension
    final_image = final_image/255.0

and the error is

NameError                                 Traceback (most recent call last)
<ipython-input-2-12ff200c967e> in <module>
     48                 face_roi = roi_color[ey: ey+eh, ex:ex + ew]
     49     #error face_roi not defined
---> 50     final_image = cv2.resize(face_roi, (224,224))
     51     final_image = np.expand_dims(final_image,axis=0) ## needed fourth dimension
     52     final_image = final_image/255.0

NameError: name 'face_roi' is not defined

I was following a tutorial on YouTube, here’s my full code.

import tensorflow as tf
from tensorflow import keras
from tensorflow.keras import layers
import cv2
import matplotlib.pyplot as plt
import numpy as np
path = "haarcascade_frontalface_default.xml"
font_scale = 1.5
font = cv2.FONT_HERSHEY_PLAIN
#set the rectangle background to white
rectangle_bgr = (255,255,255)
#make black image
img = np.zeros((500,500))
#set some text
text = "some text in a box"
#get the width and height of the text box
(text_width, text_height) = cv2.getTextSize(text, font, fontScale=font_scale, thickness=1)[0]
#set the text start position
text_offset_x = 10
text_offset_y = img.shape[0] - 25
#make the coords of the box with a small padding of two pixels
box_coords = ((text_offset_x, text_offset_y), (text_offset_x + text_width + 2, text_offset_y - text_height -2))
cv2.rectangle(img, box_coords[0], box_coords[1], rectangle_bgr, cv2.FILLED)
cv2.putText(img, text, (text_offset_x, text_offset_y), font, fontScale=font_scale, color=(0, 0, 0), thickness=1)

cap = cv2.VideoCapture('yt1s.com - 27 Emotions Every Actor Should Know.mp4')
#if not cap.isOpened():
    #cap = cv2.VideoCapture(0)
#if not cap.isOpened():
    #raise IOError("Cannot Open webcam")
    
while True:
    ret,frame = cap.read()
    #eye_cascade = cv2.CascadeClassifier(cv2.data.haarcascades + 'haarcascade_eye.xml')
    faceCascade = cv2.CascadeClassifier(cv2.data.haarcascades + 'haarcascade_frontalface_default.xml')
    gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
    #print(faceCascade.empty())
    faces = faceCascade.detectMultiScale(gray,1.1,4)
    for x,y,w,h in faces:
        roi_gray = gray[y:y+h, x:x+w]
        roi_color = frame[y:y+h, x:x+w]
        cv2.rectangle(frame, (x,y), (x+w, y+h), (255,0,0), 2)
        facess = faceCascade.detectMultiScale(roi_gray)
        if len(facess) == 0:
            print("Face not detected")
        else: 
            for (ex,ey,ew,eh) in facess:
                face_roi = roi_color[ey: ey+eh, ex:ex + ew]
    #error face_roi not defined 
    final_image = cv2.resize(face_roi, (224,224))
    final_image = np.expand_dims(final_image,axis=0) ## needed fourth dimension
    final_image = final_image/255.0

    font = cv2.FONT_HERSHEY_SIMPLEX

    Predictions = new_model.predict(final_image)

    font_scale = 1.5
    font = cv2.FONT_HERSHEY_PLAIN

    if (np.argmax(Predictions)==0):
        status = "Angry"
        x1,y1,w1,h1 = 0,0,175,75
        #draw black background rectangle
        cv2.rectangle(frame, (x1,x1),(x1 + w1, y1 + h1), (0,0,0), -1)
        #Add text
        cv2.putText(frame, status, (x1 + int(w1/10),y1 + int(h1/2)), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0,0,255), 2)

        cv2.putText(frame, status, (100, 150), font, 3, (0, 0, 255),2,cv2.LINE_4)
        
        cv2.rectangle(frame, (x,y), (x+w, y+h), (0, 0, 255))
    
    elif (np.argmax(Predictions)==1):
        status = "Disgust"
        x1,y1,w1,h1 = 0,0,175,75
        #draw black background rectangle
        cv2.rectangle(frame, (x1,x1),(x1 + w1, y1 + h1), (0,0,0), -1)
        #Add text
        cv2.putText(frame, status, (x1 + int(w1/10),y1 + int(h1/2)), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0,0,255), 2)

        cv2.putText(frame, status, (100, 150), font, 3, (0, 0, 255),2,cv2.LINE_4)
        
        cv2.rectangle(frame, (x,y), (x+w, y+h), (0, 0, 255))

    elif (np.argmax(Predictions)==2):
        status = "Fear"
        x1,y1,w1,h1 = 0,0,175,75
        #draw black background rectangle
        cv2.rectangle(frame, (x1,x1),(x1 + w1, y1 + h1), (0,0,0), -1)
        #Add text
        cv2.putText(frame, status, (x1 + int(w1/10),y1 + int(h1/2)), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0,0,255), 2)

        cv2.putText(frame, status, (100, 150), font, 3, (0, 0, 255),2,cv2.LINE_4)
        
        cv2.rectangle(frame, (x,y), (x+w, y+h), (0, 0, 255))

    elif (np.argmax(Predictions)==3):
        status = "Happy"
        x1,y1,w1,h1 = 0,0,175,75
        #draw black background rectangle
        cv2.rectangle(frame, (x1,x1),(x1 + w1, y1 + h1), (0,0,0), -1)
        #Add text
        cv2.putText(frame, status, (x1 + int(w1/10),y1 + int(h1/2)), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0,0,255), 2)

        cv2.putText(frame, status, (100, 150), font, 3, (0, 0, 255),2,cv2.LINE_4)
        
        cv2.rectangle(frame, (x,y), (x+w, y+h), (0, 0, 255))    
    
    elif (np.argmax(Predictions)==4):
        status = "Sad"
        x1,y1,w1,h1 = 0,0,175,75
        #draw black background rectangle
        cv2.rectangle(frame, (x1,x1),(x1 + w1, y1 + h1), (0,0,0), -1)
        #Add text
        cv2.putText(frame, status, (x1 + int(w1/10),y1 + int(h1/2)), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0,0,255), 2)

        cv2.putText(frame, status, (100, 150), font, 3, (0, 0, 255),2,cv2.LINE_4)
        
        cv2.rectangle(frame, (x,y), (x+w, y+h), (0, 0, 255))
    
    elif (np.argmax(Predictions)==5):
        status = "Suprise"
        x1,y1,w1,h1 = 0,0,175,75
        #draw black background rectangle
        cv2.rectangle(frame, (x1,x1),(x1 + w1, y1 + h1), (0,0,0), -1)
        #Add text
        cv2.putText(frame, status, (x1 + int(w1/10),y1 + int(h1/2)), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0,0,255), 2)

        cv2.putText(frame, status, (100, 150), font, 3, (0, 0, 255),2,cv2.LINE_4)
        
        cv2.rectangle(frame, (x,y), (x+w, y+h), (0, 0, 255))
    else:
        status = "Neutral"
        x1,y1,w1,h1 = 0,0,175,75
        #draw black background rectangle
        cv2.rectangle(frame, (x1,x1),(x1 + w1, y1 + h1), (0,0,0), -1)
        #Add text
        cv2.putText(frame, status, (x1 + int(w1/10),y1 + int(h1/2)), cv2.FONT_HERSHEY_SIMPLEX, 0.7, (0,0,255), 2)

        cv2.putText(frame, status, (100, 150), font, 3, (0, 0, 255),2,cv2.LINE_4)
        
        cv2.rectangle(frame, (x,y), (x+w, y+h), (0, 255, 0))

        cv2.imshow('Face Emotion Recognition',frame)

        if cv2.waitKey(2) & 0xFF == ord('q'):
            break
cap.release()
cv2.destroyAllWindows()

If you follow some tutorial then you could add link to this tutorial.

As for me you have wrong indentations and code should be inside for-loop.

Line final_image = ... should have the same indentation as face_roi = ...

1 Like

and how could that happen?

perhaps the loop that sets this variable, runs zero times.

please learn to debug python code.

https://docs.python.org/3/library/pdb.html