cv2.error: OpenCV(4.1.0) C:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'

[rezabrg]

• face_recognition version:4.1.0
• Python version:3.7
• Operating System:windows 10

Description

I'm having problem to run this program, the error under below

gray = cv2.cvtColor(im,cv2.COLOR_BGR2GRAY) cv2.error: OpenCV(4.1.0) C:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'

What I Did

Paste the command(s) you ran and the output.
If there was a crash, please include the traceback here.

[rafaelpsimoes]

i have the same problem

[ageitgey]

This a secondary error that basically just means the image you are trying to process didn't load and was empty.

If you grabbed the image dara from the camera, it means the camera connection failed or isn't configured correctly. If you loaded an image file, it means the loading failed.

[tarvihafatima]

I was facing this issue and by removing special characters from the image_file_name the issue was resolved.

Example: Renaming "48172454-thymianblätter.jpg" to "48172454-thymian.jpg".

[yashpatel7025]

I am using hik vision's camera and i am getting same error...i think my laptop's processor is not able to load the frames due to very high resolution and frame rate

[dinezh256]

I am having the same issue. Is image resolution causing the problem?

[ghost]

I have same problem. My old code is : cap = cv2.VideoCapture(1)

Then I change my code, and problem has solved. Probably, opencv accepts my finger print input as a camera. Thus, I change VideoCapture parameter as follows: cap = cv2.VideoCapture(0)

[vijaypearl]

how to solve this error. anyone has answer for this error: OpenCV(4.1.0) C:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'

[nikhilsupertramp]

this problem occcurs when you dont declare what 'im' is or the image has not been loaded to the variable 'im'/. if you're using your webcam to capture then use cap = cv2.VideoCapture(-1) on linux cap = cv2.VideoCapture(0) on windows and 'im' must be ret, im = cap.read(). So it will read the image properly. if you do follow these steps the error must not occur.

[nikhilsupertramp]

Now I guess we can close this issue. @ageitgey @rezabrg @rafaelpsimoes

[harichandu13]

@rezabrg download the required haarcascades it will work https://github.com/opencv/opencv/tree/master/data/haarcascades

[bakhtiyar8]

In my case, I found that in the settings of windows 10, permission to access camera has been disabled to any applications

[Bilel-Marzougui]

I am using hik vision's camera and i am getting same error...i think my laptop's processor is not able to load the frames due to very high resolution and frame rate

Did you find a solution?

[teja2002]

cv2.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' how to solve this

[thoangnguyen1308]

gray = cv2.cvtColor(image_frame, cv2.COLOR_BGR2GRAY)

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'

mn biết lỗi này là sao k ạ

[sohanatarafder99]

The same is happening with me

[AnabetsyR]

I realized I wasn't in the same dir as the image.I was trying to load an image from Desktop using just the image name.jpg. I changed dir into Desktop and everything worked fine.

[Shubhangipanda]

I am facing the same issue? what is causing the problem?

[Ehabur]

I have the same problem the reason was the image name in the folder was different from the one i was calling from cv2.imread function. properly load the images. hope it helps

[Ashutosh002]

Having the same error... Please help out!!

error -

[ceaqw]

If you use a camera: cv2.VideoCapture(0) #win cv2.VideoCapture(-1) #linux If you play local video: cv2.VideoCapture("videoFilePath")

[mohamedrashik]

Same error

Traceback (most recent call last): File "basic/imageread.py", line 5, in img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY) cv2.error: OpenCV(4.2.0) /io/opencv/modules/imgproc/src/color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cvtColor'

[shrikantkhabale]

complete image path helps me to resolve error example : cv2.imread("C:\Users\xyz\Desktop\Python\welcome.png")

[giangnguyen-bker]

ret, frame = cv2.VideoCapture('PATH').read() You should put : ''' if ret == False break ''' above: ''' gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) cv2.imshow('gray', gray) ''' Because when it comes to the final frame of the video, then there will be no frame for ''' cv2.cvtCOLOR(frame, cv2.COLOR_BGR2GRAY) '''' _src.empty() in function 'cv::cvtColor' means that is no source for the function.

[hapsuu]

cv2.error: OpenCV(4.2.0) /io/opencv/modules/imgproc/src/color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cvtColor'

Same here, the suggestions under this topic didnt work for me.

[thangphung215]

gray = cv2.cvtColor(image_frame, cv2.COLOR_BGR2GRAY)

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'

mn biết lỗi này là sao k ạ

chuyển \ thành / thử xem bạn

[GreatBruceYoung]

cv2.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' how to solve this

How to solve?

[pratsat18]

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'

Please help!

[hapsuu]

The problem is your image location. Just check carefully if you make a mistake on the location. For example if your image stored under a folder and rather in the same folder of your source code then dont use color = cv2.imread("butterfly.jpg", 1 ) instead color = cv2.imread("images/your-folder/butterfly.jpg", 1 )

[mmohamedrashik]

I also faced the same error and i fixed it by correcting the directory path. Earlier my code was cv2.imread("basic/imageread.png",1)

i fixed it by changing the path,make sure your path is correct. cv2.imread("../basic/imageread.png",1)

IDE: Pycharm OS: Ubuntu:18

[okridgway]

If the path is correct and the name of the image is OK, but you are still getting the error

use: from skimage import io img = io.imread(file_path)

instead of: cv2.imread(file_path)

The function imread loads an image from the specified file and returns it. If the image cannot be read (because of missing file, improper permissions, unsupported or invalid format), the function returns an empty matrix ( Mat::data==NULL ).

See this stackoverflow for more information.

[anujk949]

img = cv2.imread(file_path)

check img variable by printing it, if it is null/none then cv2.cvtColor will give error. enter the write path so that img variable loads an image array

[Soumarjit]

JUST complete image path, it helps me to resolve error. example : cv2.imread("C:\Users\xyz\Desktop\Python\1.png") OR img = cv2.imread('C:\Users\ASUS\Desktop\OCR Files\pytessetact using openCv\1.png')

[lovish1]

ret, frame = cv2.VideoCapture('PATH').read() You should put : ''' if ret == False break ''' above: ''' gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) cv2.imshow('gray', gray) ''' Because when it comes to the final frame of the video, then there will be no frame for ''' cv2.cvtCOLOR(frame, cv2.COLOR_BGR2GRAY) '''' _src.empty() in function 'cv::cvtColor' means that is no source for the function.

Then If gets valid ..what to do then?

[THINK989]

Hello Everyone,

I had run into the same problem a few days back. Here's my perspective on why this error came up and how can it be fixed.

The reason behind the error:-

• cv2.imread() or cv2.VideoCapture() can't find where the file is and hence gives src.empty() since None is returned instead of image or video
• If you are sure that the path specified is correct, then chances are the file being read is corrupted either completely or in a few bits and pieces.

If you got into this problem when working with an image then here is the fix:-

• Change the image, literally. If you don't want to change it then try from PIL import Image and Image.open() and see if that works and try to display the image by using matplotlib.
• Changing or reproducing the same image is the best option in my opinion.

If you got into this problem when working with a video then here is the fix:-

• After using cv2.VideoCapture('video path') Try something like below example.

  # suppose this was the source 
  cap = cv2.VideoCapture('data/input.mpg')
  # Get width and height of the frame of video
  width  = cap.get(3) # float width
  height = cap.get(4) # float height    
  # Make a video writer to see if video being taken as input inflict any changes you make
  fourcc = cv2.VideoWriter_fourcc(*"MJPG")
  out_video = cv2.VideoWriter('result/output.avi', fourcc, 20.0, (int(width), int(height)), True)
  # Then try this
  while(cap.isOpened()):
      # Read each frame where ret is a return boollean value(True or False)
      ret, frame = cap.read()
      # if return is true continue because if it isn't then frame is of NoneType in that case you cant work on that frame
      if ret:
          # Any preprocessing you want to make on the frame goes here
          gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
          # See if preprocessing is working on the frame it should
          cv2.imshow('frame', gray)
          # finally write your preprocessed frame into your output video
          out_video.write(gray) # write the modifies frame into output video 
          # to forcefully stop the running loop and break out, if it doesnt work use ctlr+c
          if cv2.waitKey(1) & 0xFF == ord('q'):
              break
     # break out if frame has return NoneType this means that once script encounters such frame it breaks out 
     # You will get the error otherwise 
      else:
          break
  # this will tell you from which frame the video is corrupted and need to be changed 
  # this could be due to an empty frame. Empty frame might be a result of mistake made while creating or editing video in tools #like adobe premier pro or other products alike 
  # You can check you output video it will contains all frame before the error is encountered

  I hope this solves your problem and you can better debug your video next time you encounter something similar.

[TruptiBobade]

I have also faced the same issue. It is not able to locate the file name which you were mentioning in the given path. Either you can specify the path while calling the file or you can define path using OS. I hope this will resolve your issue. import cv2 image = cv2.imread("C:/XYZ/images/1.jpg") image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY) plt.imshow(image, cmap="gray")

or

os.chdir('C:/XYZ/images/') image = cv2.imread("1.jpg") image = cv2.cvtColor(image, cv2.COLOR_BGR2GRAY) plt.imshow(image, cmap="gray")**

[akionsight]

I realized I wasn't in the same dir as the image.I was trying to load an image from Desktop using just the image name.jpg. I changed dir into Desktop and everything worked fine.

I too did that but the error now says cv2.error: OpenCV(4.2.0) /Users/travis/build/skvark/opencv-python/opencv/modules/imgproc/src/color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cvtColor' the code I wrote was

def detect_faces_in_video_clip(filename, window_title='Faces In Video Clip', cascade='haarcascade_frontalface_default.xml',box_colour=(0, 255, 0), line_thickness=2):

    face_cascade = cv2.CascadeClassifier(cv2.data.haarcascades + cascade)

    cap = cv2.VideoCapture(filename)
    while True:
        _, img = cap.read()
        grey = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
        faces = face_cascade.detectMultiScale(grey, 1.1, 4)
        for (x, y, w, h) in faces:
            cv2.rectangle(img, (x,y), (x+w, y+h), box_colour, line_thickness)

        cv2.imshow(window_title, img)
        k = cv2.waitKey(30)
        if k == 27:
            break

detect_faces_in_video_clip('sample.mp4')

[akionsight]

any answer

[THINK989]

@akionsight Did you try to make an output video like I have mentioned above to check which frame of the video is causing the error?

Hello Everyone,

I had run into the same problem a few days back. Here's my perspective on why this error came up and how can it be fixed.

The reason behind the error:-

• cv2.imread() or cv2.VideoCapture() can't find where the file is and hence gives src.empty() since None is returned instead of image or video
• If you are sure that the path specified is correct, then chances are the file being read is corrupted either completely or in a few bits and pieces.

If you got into this problem when working with an image then here is the fix:-

• Change the image, literally. If you don't want to change it then try from PIL import Image and Image.open() and see if that works and try to display the image by using matplotlib.
• Changing or reproducing the same image is the best option in my opinion.

If you got into this problem when working with a video then here is the fix:-

• After using cv2.VideoCapture('video path') Try something like below example.

# suppose this was the source 
cap = cv2.VideoCapture('data/input.mpg')
# Get width and height of the frame of video
width  = cap.get(3) # float width
height = cap.get(4) # float height    
# Make a video writer to see if video being taken as input inflict any changes you make
fourcc = cv2.VideoWriter_fourcc(*"MJPG")
out_video = cv2.VideoWriter('result/output.avi', fourcc, 20.0, (int(width), int(height)), True)
# Then try this
while(cap.isOpened()):
        # Read each frame where ret is a return boollean value(True or False)
        ret, frame = cap.read()
        # if return is true continue because if it isn't then frame is of NoneType in that case you cant work on that frame
        if ret:
            # Any preprocessing you want to make on the frame goes here
            gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
            # See if preprocessing is working on the frame it should
            cv2.imshow('frame', gray)
            # finally write your preprocessed frame into your output video
            out_video.write(gray) # write the modifies frame into output video 
            # to forcefully stop the running loop and break out, if it doesnt work use ctlr+c
            if cv2.waitKey(1) & 0xFF == ord('q'):
                break
       # break out if frame has return NoneType this means that once script encounters such frame it breaks out 
       # You will get the error otherwise 
        else:
            break
# this will tell you from which frame the video is corrupted and need to be changed 
# this could be due to an empty frame. Empty frame might be a result of mistake made while creating or editing video in tools #like adobe premier pro or other products alike 
# You can check you output video it will contains all frame before the error is encountered

I hope this solves your problem and you can better debug your video next time you encounter something similar.

[akionsight]

@akionsight Did you try to make an output video like I have mentioned above to check which frame of the video is causing the error?

Hello Everyone,

I had run into the same problem a few days back. Here's my perspective on why this error came up and how can it be fixed.

The reason behind the error:-

• cv2.imread() or cv2.VideoCapture() can't find where the file is and hence gives src.empty() since None is returned instead of image or video
• If you are sure that the path specified is correct, then chances are the file being read is corrupted either completely or in a few bits and pieces.

If you got into this problem when working with an image then here is the fix:-

• Change the image, literally. If you don't want to change it then try from PIL import Image and Image.open() and see if that works and try to display the image by using matplotlib.
• Changing or reproducing the same image is the best option in my opinion.

If you got into this problem when working with a video then here is the fix:-

• After using cv2.VideoCapture('video path') Try something like below example.

# suppose this was the source 
cap = cv2.VideoCapture('data/input.mpg')
# Get width and height of the frame of video
width  = cap.get(3) # float width
height = cap.get(4) # float height    
# Make a video writer to see if video being taken as input inflict any changes you make
fourcc = cv2.VideoWriter_fourcc(*"MJPG")
out_video = cv2.VideoWriter('result/output.avi', fourcc, 20.0, (int(width), int(height)), True)
# Then try this
while(cap.isOpened()):
        # Read each frame where ret is a return boollean value(True or False)
        ret, frame = cap.read()
        # if return is true continue because if it isn't then frame is of NoneType in that case you cant work on that frame
        if ret:
            # Any preprocessing you want to make on the frame goes here
            gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
            # See if preprocessing is working on the frame it should
            cv2.imshow('frame', gray)
            # finally write your preprocessed frame into your output video
            out_video.write(gray) # write the modifies frame into output video 
            # to forcefully stop the running loop and break out, if it doesnt work use ctlr+c
            if cv2.waitKey(1) & 0xFF == ord('q'):
                break
       # break out if frame has return NoneType this means that once script encounters such frame it breaks out 
       # You will get the error otherwise 
        else:
            break
# this will tell you from which frame the video is corrupted and need to be changed 
# this could be due to an empty frame. Empty frame might be a result of mistake made while creating or editing video in tools #like adobe premier pro or other products alike 
# You can check you output video it will contains all frame before the error is encountered

I hope this solves your problem and you can better debug your video next time you encounter something similar.

Yes I did but it did not work and still showed the same error

[THINK989]

I realized I wasn't in the same dir as the image.I was trying to load an image from Desktop using just the image name.jpg. I changed dir into Desktop and everything worked fine.

I too did that but the error now says cv2.error: OpenCV(4.2.0) /Users/travis/build/skvark/opencv-python/opencv/modules/imgproc/src/color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cvtColor' the code I wrote was

def detect_faces_in_video_clip(filename, window_title='Faces In Video Clip', cascade='haarcascade_frontalface_default.xml',box_colour=(0, 255, 0), line_thickness=2):

    face_cascade = cv2.CascadeClassifier(cv2.data.haarcascades + cascade)

    cap = cv2.VideoCapture(filename)
    while True:
        _, img = cap.read()
        grey = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
        faces = face_cascade.detectMultiScale(grey, 1.1, 4)
        for (x, y, w, h) in faces:
            cv2.rectangle(img, (x,y), (x+w, y+h), box_colour, line_thickness)

        cv2.imshow(window_title, img)
        k = cv2.waitKey(30)
        if k == 27:
            break

detect_faces_in_video_clip('sample.mp4')

@akionsight

Your Code works perfectly on my input video. I don't know what else might cause the issue may be version. Are your python file and video at the same location?

[nirupamudoi]

Hello Everyone,

I had run into the same problem a few days back. Here's my perspective on why this error came up and how can it be fixed.

The reason behind the error:-

• cv2.imread() or cv2.VideoCapture() can't find where the file is and hence gives src.empty() since None is returned instead of image or video
• If you are sure that the path specified is correct, then chances are the file being read is corrupted either completely or in a few bits and pieces.

If you got into this problem when working with an image then here is the fix:-

• Change the image, literally. If you don't want to change it then try from PIL import Image and Image.open() and see if that works and try to display the image by using matplotlib.
• Changing or reproducing the same image is the best option in my opinion.

If you got into this problem when working with a video then here is the fix:-

• After using cv2.VideoCapture('video path') Try something like below example.

# suppose this was the source 
cap = cv2.VideoCapture('data/input.mpg')
# Get width and height of the frame of video
width  = cap.get(3) # float width
height = cap.get(4) # float height    
# Make a video writer to see if video being taken as input inflict any changes you make
fourcc = cv2.VideoWriter_fourcc(*"MJPG")
out_video = cv2.VideoWriter('result/output.avi', fourcc, 20.0, (int(width), int(height)), True)
# Then try this
while(cap.isOpened()):
        # Read each frame where ret is a return boollean value(True or False)
        ret, frame = cap.read()
        # if return is true continue because if it isn't then frame is of NoneType in that case you cant work on that frame
        if ret:
            # Any preprocessing you want to make on the frame goes here
            gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
            # See if preprocessing is working on the frame it should
            cv2.imshow('frame', gray)
            # finally write your preprocessed frame into your output video
            out_video.write(gray) # write the modifies frame into output video 
            # to forcefully stop the running loop and break out, if it doesnt work use ctlr+c
            if cv2.waitKey(1) & 0xFF == ord('q'):
                break
       # break out if frame has return NoneType this means that once script encounters such frame it breaks out 
       # You will get the error otherwise 
        else:
            break
# this will tell you from which frame the video is corrupted and need to be changed 
# this could be due to an empty frame. Empty frame might be a result of mistake made while creating or editing video in tools #like adobe premier pro or other products alike 
# You can check you output video it will contains all frame before the error is encountered

I hope this solves your problem and you can better debug your video next time you encounter something similar.

i am getting this problem while loading my images from dataset. I am running the code from the same folder within the same directory but the dataset is situated on a different folder. what should I do?

[THINK989]

i am getting this problem while loading my images from dataset. I am running the code from the same folder within the same directory but the dataset is situated on a different folder. what should I do?

Hello @nirupamudoi That depends on your file structure If your file structure is like this

ROOT
    |
    |
    ----Data
              |
              ----Your Images
    |
    ----Script
              |
              ---- Your Python Script

Then you can use "../" in your python script for eg:-

cv2.imread("../Data/image_name.jpg")

Also, in any case, a complete path would work for eg:-

cv2.imread("D:/data/image_name.jpg")

[vedantraut]

error: OpenCV(4.3.0) C:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'

I was facing the same issue, but as soon as I changed my image to a low-resolution image the code worked.

[KARTHIK-VEL]

[ WARN:0] global C:\projects\opencv-python\opencv\modules\videoio\src\cap_msmf.cpp (681) CvCapture_MSMF::initStream Failed to set mediaType (stream 0, (0x0 @ 1) MFVideoFormat_RGB24(unsupported media type) i having this error please help me

[anuradhabn]

For 'cv2.error: OpenCV(4.3.0) C:\projects\opencv-python\opencv\modules\imgproc\src\color.cpp:182: error: (-215:Assertion failed) !_src.empty() in function 'cv::cvtColor'' error, I was able to resolve it with the below code. I think it has got to do with the resolution. Change the scalefactor from 1 to 1.3 or 1.4.

a) Image : faces = face_cascade.detectMultiScale(gray, 1.1, 4) & it works. b) Video : faces = face_cascade.detectMultiScale(gray, 1.9, 4) & it is still not working.

[cihan063]

ret, frame = cv2.VideoCapture('PATH').read() You should put : ''' if ret == False break ''' above: ''' gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) cv2.imshow('gray', gray) ''' Because when it comes to the final frame of the video, then there will be no frame for ''' cv2.cvtCOLOR(frame, cv2.COLOR_BGR2GRAY) '''' _src.empty() in function 'cv::cvtColor' means that is no source for the function.

It worked for me thanks a lot

[Divyesh24]

this problem occcurs when you dont declare what 'im' is or the image has not been loaded to the variable 'im'/. if you're using your webcam to capture then use cap = cv2.VideoCapture(-1) on linux cap = cv2.VideoCapture(0) on windows and 'im' must be ret, im = cap.read(). So it will read the image properly. if you do follow these steps the error must not occur. great it works,

[VipulPandey-arch]

in my case i have put the image path from the properties of the image as well as please write cv2. press tab(if using jupyter notebook) and the search for the correct syntax , for my case code is like this full = cv2.imread(r'C:\Users\vipul.pandey\Desktop\computer vision\Computer-Vision-with-Python\DATA\1.jpg') full = cv2.cvtColor(full, cv2.COLOR_BGR2RGB)

dont forget to put r before the path i think ur problem will be solved

[akionsight]

I found another solution

capture = cv2.VideoCapture(1, cv2.CAP_DSHOW)

this is what worked for me 😁

[ritikkumar55]

I found another solution

capture = cv2.VideoCapture(1, cv2.CAP_DSHOW)

this is what worked for me 😁

also for me...