The AI of the Beholder: Seeing with Computer Vision 👀

This repository contains all the code we will be using throughout this BuildingBlocs 2023 Workshop.

Navigating files

All the sections are numbered with the corresponding section number and header. Feel free to upload your own images to the img/ folder for testing!

Dependencies

These codes minimally required opencv-python and numpy to run. This workshop uses opencv-python==4.7.0, so it may help to check the version you're using.

Helpful links

OpenCV tutorials: https://docs.opencv.org/4.7.0/d9/df8/tutorial_root.html
OpenCV documentation: https://docs.opencv.org/4.7.0/

S1: Image Processing

• OpenCV Documentation: https://docs.opencv.org/4.x/d2/d96/tutorial_py_table_of_contents_imgproc.html
• All the ColourConversionCodes: https://docs.opencv.org/3.4/d8/d01/groupimgproccolor__conversions.html
• Image Blurring and Enhancement: https://www.geeksforgeeks.org/image-enhancement-techniques-using-opencv-python/

S2A: Feature Extraction

• OpenCV Feature Detectors: https://docs.opencv.org/4.x/db/d27/tutorial_py_table_of_contents_feature2d.html
• Harris Corner Detection: https://docs.opencv.org/4.x/dd/d1a/groupimgprocfeature.html#gac1fc3598018010880e370e2f709b4345
• Shi-Tomasi Corner Detection: https://docs.opencv.org/4.x/dd/d1a/groupimgprocfeature.html#ga1d6bb77486c8f92d79c8793ad995d541
• Canny Edge Detection: https://docs.opencv.org/3.4/da/d22/tutorial_py_canny.html
• Simple Blob Detector: https://docs.opencv.org/4.x/d0/d7a/classcv_1_1SimpleBlobDetector.html

S2B: Feature Matching

• OpenCV Tutorial: https://docs.opencv.org/4.x/dc/dc3/tutorial_py_matcher.html

S3A: Haar-cascade Object Detection

• OpenCV Tutorial: https://docs.opencv.org/4.7.0/db/d28/tutorial_cascade_classifier.html
• OpenCV Pre-Trained Cascades: https://github.com/opencv/opencv/tree/4.7.0/data/haarcascades

S3B: DNN-based Face Detection

• OpenCV Tutorial: https://docs.opencv.org/4.x/d0/dd4/tutorial_dnn_face.html
• FaceDetectorYN Documentation: https://docs.opencv.org/4.x/df/d20/classcv_1_1FaceDetectorYN.html
• Model Download Link: https://github.com/opencv/opencv_zoo/tree/master/models/face_detection_yunet
• Scientific Paper: https://doi.org/10.1007/s11633-023-1423-y

S4: OpenCV GUI and Video

• OpenCV Tutorial: https://docs.opencv.org/3.4/dc/d4d/tutorial_py_table_of_contents_gui.html

Common issues

1. File loading issues

Issue: ...Can't find required data file... or ...Can't read ONNX file..., etc.

Possible Problem 1: Our code often uses ../<filepath> as we assume it is run from the individual file itself. Solution: You can replace ../ with ./ if you are running from the parent folder (e.g. using VSCode).

Possible Problem 2: Our code uses <directory>/<filepath>.
Solution: If you are on a windows OS, kindly replace all / with \\ instead.

2. Other issues?

Please ask our friendly Tech Facils during the event, or you can look for help online / reach out to your group facils.
You can also try using the Google Colab here instead: https://bit.ly/bbcs23-opencv-colab