IN OPENCV 3 the cv2.findContours function return 3 values. namely im2, contours, hierarchy.

The code from project 1 throws an error about the unpacking of value or value assign error.

Traceback (most recent call last): File "C:/Users/mayur/PycharmProjects/OpenCV projects/read.py", line 20, in findColor ( img, mycolors ) File "C:/Users/mayur/PycharmProjects/OpenCV projects/read.py", line 16, in findColor cv2.imshow(img,mask) cv2.error: OpenCV(4.5.2) :-1: error: (-5:Bad argument) in function 'imshow'

Overload resolution failed:

• Can't convert object of type 'numpy.ndarray' to 'str' for 'winname'
• Can't convert object of type 'numpy.ndarray' to 'str' for 'winname'
• Can't convert object of type 'numpy.ndarray' to 'str' for 'winname'

Hello,

I'm starting to learning python and I'm having difficulties to read the lena's image. When I try to run the program appers the error "no such file or directory". I would like to know how I can fix that.

Att

Continue getting this error for drone face tracking course, I think it is due to the file. Any ideas?

My Code:

import cv2 import numpy as np

def findFace(img): faceCascade = cv2.CascadeClassifier('Resources/haarcascade_frontalface_default.xml') imgGray = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) faces = faceCascade.detectMultiScale(imgGray,1.1,8)

myFaceListC = []
myFaceListArea = []

for (x,y,w,h) in faces:
    cv2.rectangle(img,(x,y),(x + w, y + h),(0,0,255),2)

cap = cv2.VideoCapture(0)

while True: _, img = cap.read() findFace(img) cv2.imshow("Output",img) cv2.waitKey(1)

Error:

File "C:/Users/zachd/PycharmProjects/droneproject2/venv/Face Tracking.py", line 20, in findFace(img) File "C:/Users/zachd/PycharmProjects/droneproject2/venv/Face Tracking.py", line 7, in findFace faces = faceCascade.detectMultiScale(imgGray,1.1,8) cv2.error: OpenCV(4.5.1) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-oduouqig\opencv\modules\objdetect\src\cascadedetect.cpp:1689: error: (-215:Assertion failed) !empty() in function 'cv::CascadeClassifier::detectMultiScale'

[ WARN:1] global C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-oduouqig\opencv\modules\videoio\src\cap_msmf.cpp (434) `anonymous-namespace'::SourceReaderCB::~SourceReaderCB terminating async callback

From project 1 you use the Colorpicker.py to get the right values you need. when running the Code I get a problem with it at:

[ WARN:0] global C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-2b5g8ysb\opencv\modules\videoio\src\cap_msmf.cpp (435) `anonymous-namespace'::SourceReaderCB::~SourceReaderCB terminating async callback Traceback (most recent call last): imgHsv = cv2.cvtColor(img, cv2.COLOR_BGR2HSV) cv2.error: OpenCV(4.4.0)

Im using python 3.7.6 and I have cv2 imported

The image lambo.png is used in chapter 7, and also in the video for chapter 3.

In the Resources directory the file is labeled lambo.PNG so the above exercises throws an error.

Changing the Resources filename to lambo.png will take care of these errors.

Note: chapter 3 video code uses lambo.png and the GitHub code uses shapes.png. This really is not a problem if lambo.PNG is changed to lambo.png