Rebuild the library with windows gtk 2 x or cocoa support

I had this exact same issue a few weeks back and I’d like to perhaps complement some of the answers touching the headless elephant in the room.

My complex project incorporates a few in-house subprojects by other colleagues. These tend to be developed and tested independently, so no cross-contamination occurs. However, since one of them used opencv-python and another went with opencv-python-headless, the final build installed both.

THIS IS THE PROBLEM!

Whenever I had both, a number of functions, particularly those pertaining visualisation, now failed. Worse: pip list revealed both opencv- versions installed! To make matters worse, whenever I uninstalled and installed again opencv-python (a simple --upgrade never worked, as it claimed the latest version was there and nothing needed upgrading), then it started working. We all hate witchcraft, so…

I went down the compilation rabbit hole and obviously nothing good was there to be found.

How does pip know it?

if you check into your .venv\Lib\site-packages, you’ll find the following two folders:

• opencv_python-4.5.4.60.dist-info
• opencv_python-headless-4.5.4.60.dist-info

or whatever your version might be. These are the folders where pip gets its metadata from, but not where the actual code is. In fact, you don’t do import opencv-..., but rather import cv2.

You do import cv2 in both cases! In fact, -headless is a crippled drop-in for the real thing. So, if you look up in your list, you’ll find a cv2 folder. Both libraries deposit their code in this folder. As we know, when it comes to saving files, the last on the scene wins.

Order! Order!

(Ok, I miss John Bercow.)

Now, both libraries saving to the same folder, what is the order? Since they don’t depend on one another, and in my case where poetry is being used to manage dependencies, alphabetical order is the default, and (drumroll) -headless comes last.

Solution

At some point, I just decided to go nuts and remove -headless altogether. I am not the CV dev in the team, so I was just grasping for straws , but… it worked! That’s when I looked int the whole drop-in thing.

My colleagues were developing with a simple requirements.txt file, so when it came to gathering requirements in a nice proper pyproject.toml file, I just left the -headless option out.

Bottom line

You can’t have both. Whenever you have multi-part projects, I highly advise to run through the pip list after the environment is built and check for the couple. If you find both, always remove the -headless, as it is a subset of the main one.

Achtung: check your .venv\pyvenv.cfg for a line with:

• include-system-site-packages = true

This line means your project will be importing any libraries (other than the standard ones) from your global Python install and if you happen to have the -headless in the global environment, you’re still in trouble.

The error you’re encountering indicates that the version of OpenCV you’re using was built without GUI support for window management. To resolve this issue and display the camera feed in a window, you can either rebuild OpenCV with GUI support or use an alternative library to display the camera feed. Here are two possible solutions:

Solution 1: Rebuild OpenCV with GUI Support (Recommended)

Ensure you have CMake installed on your system.

Rebuild OpenCV with GUI support using CMake. You can do this by following these steps:

Download the OpenCV source code from the official OpenCV website: https://opencv.org/releases/

Extract the downloaded source code archive to a directory.

Open a terminal or command prompt and navigate to the directory where you extracted the OpenCV source code.

Create a build directory within the OpenCV source directory and navigate to it:
Configure the build using CMake with GUI support enabled:
using :
cmake -D CMAKE_BUILD_TYPE=RELEASE -D CMAKE_INSTALL_PREFIX=/usr/local -D BUILD_opencv_python2=OFF -D BUILD_opencv_python3=ON -D WITH_TBB=ON -D WITH_V4L=ON -D WITH_QT=ON -D WITH_OPENGL=ON ..

After successful configuration, build and install OpenCV:
make
sudo make install

Once the installation is complete, you should have OpenCV with GUI support.

Update your Python environment to use the newly built OpenCV library. You may need to uninstall the previous OpenCV package and install the new one.

Operating environment: Windows10

Python version: 3.6

OpenCV Version: 3.4.3.18

Because an image library multi-template-matching is installed, the OpenCV error when the Python program that processes an image is run again.

cv2.error: OpenCV(4.5.4-dev) D:\a\opencv-python\opencv-python\opencv\modules\highgui\src\window.cpp:1274: error: (-2:Unspecified e
rror) The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Cocoa support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script in function 'cvShowImage'

Solution:

• Open CMD, enter

pip config set global.index-url https://pypi.tuna.tsinghua.edu.cn/simple

# The above command is to set the default download of the PIP download package to Tsinghua source. The download speed will speed up. If you use the PIP to download the package, you don't have to worry about the problem of slow download.

pip install opencv-contrib-python

# Download OpenCV-Contrib-Python, this package can solve the above problem

Run the program to see if it is wrong

If it is also an error, it may be version compatibility problem, because PIP defaults to download the latest version of the package, may conflict with your old version of other packages

1. Open CMD, enter PIP Show OpenCV-Python, find the version number, such as:Version:3.4.3.18
2. General OpenCV-Contrib-Python corresponds to the OpenCV-Python version, so install, open CMD, enter:

pip install opencv-contrib-python==3.4.3.18
#                  

Similar compatibility issues can be resolved with this idea, and they will give it to how to solve other compatibility issues.

1. Open URL: https://pi.org/project/opencv-python/# History, find the specified version of the OpenCV package, see what year is released

1. Then, OpenCV-Python in the above URL is then changed to OpenCV-Contrib-Python, ie https:/pypi.org/project/opencv-contrib-python/# History, find OpenCV-Python in the computer Almost released OpenCV-Contrib-Python released by month

We have found that OpenCV-Python and OpenCV-Contrib-Python are the same, and the release time is almost consistent, but it may not be so clever, or you need to be old and realistic. Release time to solve Compatibility problem

Then you install the specified version of the package, use the command pip install package name == version number, this method can solve the bag compatibility problem to maximize

Issue

I was working on a sign language detection project on jupyter notebook. While running the code for live detection I encountered an error as shown below:

OpenCV(4.5.1) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-1drr4hl0\opencv\modules\highgui\src\window.cpp:651: error: (-2:Unspecified error) The function is not implemented. Rebuild the library with Windows, GTK+ 2.x or Cocoa support. If you are on Ubuntu or Debian, install libgtk2.0-dev and pkg-config, then re-run cmake or configure script in function ‘cvShowImage’

Despite of trying many solutions that I found online I’m still getting the same error.

The code that encountered error is :
while True:
ret, frame = cap.read()
image_np = np.array(frame)

input_tensor = tf.convert_to_tensor(np.expand_dims(image_np, 0), dtype=tf.float32)
detections = detect_fn(input_tensor)

num_detections = int(detections.pop('num_detections'))
detections = {key: value[0, :num_detections].numpy()
              for key, value in detections.items()}
detections['num_detections'] = num_detections

# detection_classes should be ints.
detections['detection_classes'] = detections['detection_classes'].astype(np.int64)

label_id_offset = 1
image_np_with_detections = image_np.copy()

viz_utils.visualize_boxes_and_labels_on_image_array(
            image_np_with_detections,
            detections['detection_boxes'],
            detections['detection_classes']+label_id_offset,
            detections['detection_scores'],
            category_index,
            use_normalized_coordinates=True,
            max_boxes_to_draw=5,
            min_score_thresh=.5,
            agnostic_mode=False)

cv2.imshow('object detection',  cv2.resize(image_np_with_detections, (800, 600)))

if cv2.waitKey(1) & 0xFF == ord('q'):
    cap.release()
    break

Please help me!

Solution

Few frustration hours later, saw this solution under the comment of the first answer by Karthik Thilakan

pip uninstall opencv-python-headless -y 

pip install opencv-python --upgrade

This worked for me in the conda environment. Thanks Karthik!

Answered By — Sachin Mohan