如何在opencv中裁剪检测到的脸部并将ROI保存为opencv python中的图像

Question

Im using opencv in python and this is my code in detecting the face and saving the face..but it does not save the roi(the face detected),i've been having trouble doing this.please help me how to fix this.

   TRAINSET = "data/lbpcascades/lbpcascade_frontalface.xml"
   DOWNSCALE = 4

   cam = cv2.VideoCapture(0) #capture a video

   cv2.namedWindow("preview")
   classifier = cv2.CascadeClassifier(TRAINSET) 

   Compare_images=[]
   for file in os.listdir("images"):
       if file.endswith(".jpg"):
          Compare_images.append(file)
while True: # try to get the first frame
    _, frame = cam.read() 

key = cv2.waitKey(20)
if(key==32):

    print "Name of Image:"

    n= raw_input()

    value=len(Compare_images)
    cv2.imwrite('images/image'+str(n)+'.jpg', frame)
    saved_image=cv2.imread("images/image"+str(n)+".jpg")
    minisize = (saved_image.shape[1]/DOWNSCALE,saved_image.shape[0]/DOWNSCALE)
    miniframe = cv2.resize(saved_image, minisize)
    faces = classifier.detectMultiScale(miniframe)
    for f in faces:
        x, y, w, h = [ v*DOWNSCALE for v in f ]     
        print x 
        print y,w,h      

        x0,y0=int(x),int(y)
        x1,y1=int(x+w),int(y+h)
        print x0,y0,y1,y0

        image = cv2.rectangle(saved_image, (x0,y0), (x1,y1), (0,0,255),2)

        roi=saved_image[y0:y1,x1:x0]#crop 
        cv2.imwrite('roi.jpg',roi)
        cv2.imshow("adsa", saved_image) 


cv2.putText(frame, "Press ESC to close.", (5, 25),
            cv2.FONT_HERSHEY_SIMPLEX, 1.0, (255,255,255))
cv2.imshow("preview", frame)

Answer 1

Do you mean?:

.
.
.
print x0,y0,x1,y1
.
.
.
roi=saved_image[y0:y1,x0:x1]

The indentation above and below the while statement seems incorrect.

Triple quotes should only be used temporarily for block quotes as they can cause problems.

Maybe use # instead:

#x0,y0=x,y
#x1,y1=x+w,y+h

Unless that is how the help for that function is suppose to read.

Including errors in your question would be helpful too.