Here is my code :
import numpy as np
import cv2
face_cascade = cv2.CascadeClassifier('haarcascase_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')
cap = cv2.VideoCapture(0)
while True:
ret, img = cap.read()
gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray,1.3,5)
for (x,y,w,h) in faces:
cv2.rectangle(img, (x,y), (x+w, y+h), (255,0,0), 2)
roi_gray = gray[y:y+h, x:x+w]
roi_color = img[y:y+h, x:x+w]
eye = eye_cascade.detectMultiScale(roi_gray)
for (ex,ey,ew,eh) in eye:
cv2.rectangle(roi_color, (ex,ey), (ex+ew, ey+eh), (0,255,0), 2 )
cv2.imshow('img',img)
k= cv2.waitKey(30) & 0xff
if k == 27:``
break
cap.release()
cap.destroyAllWindows()
These are the errors I'm getting:
error: OpenCV(4.2.0)
C:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:182:
error: (-215:Assertion failed) !_src.empty() in function
'cv::cvtColor'
error Traceback (most recent call
last) in
3 while True:
4 ret, img = cap.read()
----> 5 gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
6 faces = face_cascade.detectMultiScale(gray,1.3,5)
7 for (x,y,w,h) in faces:
error: OpenCV(4.2.0)
C:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:182:
error: (-215:Assertion failed) !_src.empty() in function
'cv::cvtColor'
in your code have 3 little errors:
1= if k == 27:``` for solve first that delete `` 2=cap.destroyAllWindows()for solve secound, typecv2.destroyAllWindows() 3=('haarcascase_frontalface_default.xml')for solve third ,just type thishaarcascade_frontalface_default.xml`
you type cascase but that is cascade.
There could be numerous reasons as to why it doesn't work (eg. some OS will require that you grant permission to your term to access the webcam), however there's a couple of issues with your code:
start of the while loop: you don't check the value of the parameter ret. It's good practice to check its value with a small check like if not ret: break to exit the loop. That won't help with your webcam not working, but that will prevent the error that you are seeing (retis False, so img is likely empty and had no data)
End of your code. destroyAllWindows is a method in the cv2 namespace, not a property of your capture. You should call cv2.destroyAllWindows() instead of cap.destroyAllWindows()
Related
I am trying to get temperature from Flir thermal camera with Python and OpenCV in real time, as shown in this video.
I am using the code below for face detection. It works for regular camera but it does not work with the thermal one, which gives me this error:
[ WARN:0] global C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-95hbg2jt\opencv\modules\videoio\src\cap_msmf.cpp (435) `anonymous-namespace'::SourceReaderCB::~SourceReaderCB terminating async callback
Traceback (most recent call last):
File "c:\Users\Render\Documents\BTK_Python\face_detection.py", line 18, in <module>
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
cv2.error: OpenCV(4.4.0) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-95hbg2jt\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'
import cv2
face_cascade = cv2.CascadeClassifier("haarcascade_frontalface_default.xml")
cap = cv2.VideoCapture(1)
while True:
_, img = cap.read()
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, 1.1, 4)
for (x, y, w, h) in faces:
cv2.rectangle(img, (x,y), (x+w, y+h), (255,255,0), 4)
cv2.imshow("banu-taner", img)
k = cv2.waitKey(30) & 0xff
if k == 27:
break
cap.realase()
I am following an opencv tutorial here: https://www.youtube.com/watch?v=PmZ29Vta7Vc
At 11:36 when he runs his code, it works fine, but when I run my code, I get an error:
Traceback (most recent call last):
File "C:/Users/Joshua/OneDrive/VscodePrograms/MyPythonFolder/facialRec/main.py", line 11, in <module>
faces = face_cascade.detectMultiScale(gray, scaleFactor=1.5, minNeighbors=5)
cv2.error: OpenCV(4.2.0) C:\projects\opencv-python\opencv\modules\objdetect\src\cascadedetect.cpp:1689: error: (-215:Assertion failed) !empty() in function 'cv::CascadeClassifier::detectMultiScale'
[ WARN:0] global C:\projects\opencv-python\opencv\modules\videoio\src\cap_msmf.cpp (674) SourceReaderCB::~SourceReaderCB terminating async callback
Here is the code:
import numpy as np
import cv2
face_cascade = cv2.CascadeClassifier('casades/data/haardcascade_frontalface_alt2.xml')
cap = cv2.VideoCapture(0)
while (True):
ret, frame = cap.read()
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, scaleFactor=1.5, minNeighbors=5)
for (x, y, w, h) in faces:
print(x, y, w, h)
cv2.imshow('frame', frame)
if cv2.waitKey(20) & 0xFF == ord('q'):
break
cap.release()
cv2.destroyAllWindows()
Please help!
The problem is in the CascadeClassifier's path:
face_cascade = cv2.CascadeClassifier('cascades/data/haarcascade_frontalface_alt2.xml')
I think now it should be working fine.
I'm currently trying to run a simple python program to detect face and eyes.
I downloaded the appropriate classifiers and they're in the same directory. I even checked my camera settings and it's set to on with permission to python. Any ideas how to solve this?
import cv2
import numpy as np
face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
eye_cascade = cv2.CascadeClassifier('haarcascade_eye.xml')
cap = cv2.VideoCapture(0)
while True:
ret, img = cap.read()
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, 1.3, 5)
for (x,y,w,h) in faces:
cv2.rectange(img, (x,y), (x+w, y+h), (255,0,0), 2)
roi_gray = gray[y:y+h, x:x+w]
roi_color = img[y:y+h, x:x+w]
eyes = eye_cascade.detectMultiScale(roi_gray)
for (ex,ey,ew,ehh) in eyes:
cv2.rectangle(roi_color, (ex,ey), (ex+ew,ey+eh), (0,255,0), 2)
cv2.imshow('img',img)
k = cv2.waitKey(30) & 0xff
if k == 27:
break
cap.release()
cv2.destroyAllWindows()
Why does this OpenCV program give the error:
My camera settings show that python is using it:
Thank you!
!_src.empty() means you have an empty frame
You can check the frame to make sure you actually get the image:
ret, img = cap.read()
if img is not None:
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
else: < implement how you want to deal with empty frame >
How can I make an OpenCV face detection for Python 2.7 on a Mac. I have tried many different codes but they all don't work. I am running them in terminal.
I get this error:
cv2.error: OpenCV(4.0.0) /Users/travis/build/skvark/opencv-python/opencv/modules/objdetect/src/cascadedetect.cpp:1658: error: (-215:Assertion failed) !empty() in function 'detectMultiScale'
This seems to be right but I can't figure out what the error is. Here is the code for the face detection.
import numpy as np
import cv2
faceCascade =
cv2.CascadeClassifier('Cascades/haarcascade_frontalface_default.xml')
cap = cv2.VideoCapture(0)
cap.set(3,640) # set Width
cap.set(4,480) # set Height
while True:
ret, img = cap.read()
img = cv2.flip(img, -1)
gray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
faces = faceCascade.detectMultiScale(
gray,
scaleFactor=1.2,
minNeighbors=5,
minSize=(20, 20)
)
for (x,y,w,h) in faces:
cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)
roi_gray = gray[y:y+h, x:x+w]
roi_color = img[y:y+h, x:x+w]
cv2.imshow('video',img)
k = cv2.waitKey(30) & 0xff
if k == 27: # press 'ESC' to quit
break
cap.release()
cv2.destroyAllWindows()
Your error message indicates that the file path may be invalid, the program can't find .xml file. And you may want to replace 'Cascades/haarcascade_frontalface_default.xml' with a absolute path such as 'username/file/../cascade.xml'
I am trying to create a face detection program. When I execute the below code:
import numpy as np
import cv2
face_cascade = cv2.CascadeClassifier('../../Practica - Proyectos/Practica -
OpenCV/cascades/data/haarcascade_frontalface_alt2.xml')
captura = cv2.VideoCapture(0)
while(True):
ret, frame = captura.read()
gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
faces = face_cascade.detectMultiScale(gray, scaleFactor=1.5, minNeighbors=5)
for (x, y, w, h) in faces:
print(x,y,w,h)
cv2.imshow('frame', frame)
if cv2.waitKey(20) & 0xFF == ord('q'):
break
captura.release()
cv2.destroyAllWindows()
The following error occurs:
Traceback (most recent call last): File "c:\xampp\htdocs\Practica - Proyectos\Practica - OpenCV\facialRec.py", line 20, in faces = face_cascade.detectMultiScale(gray, scaleFactor=1.5, minNeighbors=5) cv2.error: OpenCV(3.4.1) C:\projects\opencv-python\opencv\modules\objdetect\src\cascadedetect.cpp:1698: error: (-215) !empty() in function cv::CascadeClassifier::detectMultiScale
I understand that there is a problem with the route but I can not guess why it does not execute. The code is supposed to execute and read the different points on my face.
Thank you very much for your time in advance.