咨询：在Cloud9（Ubuntu Server）中能否运行已安装的OpenCV项目

Absolutely, you can run OpenCV projects on your Cloud9 Ubuntu Server environment! Let me walk you through how to confirm your setup is solid and get started with a quick test.

First: Double-Check Your OpenCV Installation #

Your initial command sudo apt-get libopencv-* is missing the install flag—no wonder you might be unsure if it worked! Let's fix that first, then verify the installation:

1. Re-run the correct install command (if you haven't already):

   sudo apt-get install libopencv-*
   

2. Confirm it's installed properly by checking the version:

   pkg-config --modversion opencv
   

If this returns a version number (like 4.5.4), you're good to go. If you get an error, you may need to run sudo apt-get update first to refresh your package lists.

Test With a Simple OpenCV Project #

Let's build a tiny test script to prove everything works. We'll use Python since it's straightforward for quick tests:

1. Create a new file in your Cloud9 workspace named test_opencv.py
2. Paste this code into it:

   import cv2
   
   # Try loading a local image (you can upload one to your workspace, or skip to the fallback)
   test_img = cv2.imread("my_test_image.jpg")
   
   if test_img is not None:
       print("✅ Image loaded successfully!")
       print(f"Image dimensions: {test_img.shape[1]}px wide x {test_img.shape[0]}px tall")
   else:
       print("ℹ️ No local image found—using OpenCV's built-in sample image instead")
       # Use OpenCV's pre-included test image (no extra files needed)
       sample_img = cv2.imread(cv2.samples.findFile("starry_night.jpg"))
       print(f"✅ Sample image loaded! Dimensions: {sample_img.shape[1]}px x {sample_img.shape[0]}px")
   

3. Run the script with:

   python3 test_opencv.py
   

If you see checkmarks and dimension details, your OpenCV setup is fully functional.

Cloud9-Specific Tips #

• Displaying images: Since Cloud9 is browser-based, you can't use cv2.imshow() directly. Instead, save processed images to a file with cv2.imwrite("output.jpg", your_image)—then right-click the file in Cloud9's file explorer and select "Preview" to see it.
• C++ projects: If you prefer C++, you can compile your code with g++ using OpenCV's linker flags. Get the correct flags with pkg-config --cflags --libs opencv, then compile like this:

  g++ -o my_opencv_app my_opencv_code.cpp $(pkg-config --cflags --libs opencv)
  

内容的提问来源于stack exchange，提问作者bob torus