clausal-opencv

OpenCV (cv2) predicates for Clausal Prolog.

Wraps the computer-vision functions of opencv-python as Clausal Prolog predicates: image I/O, properties, arithmetic, color conversion, filtering, morphology, thresholding, contours, geometric transformations, non-mutating drawing, classical feature detection, classical object detection, camera calibration, and video I/O.

Install

pip install clausal-opencv

opencv-python (OpenCV 4; OpenCV 5 moved KAZE, AKAZE, BRISK, HOG and the cascade classifier out of the main package) is pulled in as a dependency. For headless environments, install opencv-python-headless<5 first to override the default.

Use

In a seam (.seam) file:

-import_from(opencv, [imread, shape, IMREAD_COLOR])

test("read an image and query its shape") <- (
    imread("photo.jpg", IMREAD_COLOR, IMG),
    shape(IMG, [H, W, 3]),
    H > 0,
    W > 0
)

See docs/ for the predicate catalogue and worked examples.

Implementation status

See ../../implementation_plans/opencv/overview.md.

• Phase 1 — Core, I/O, Properties, Arithmetic
• Phase 2 — Color Conversions
• Phase 3 — Filtering and Morphology
• Phase 4 — Thresholding and Contours
• Phase 5 — Geometric Transformations
• Phase 6 — Drawing (non-mutating)
• Phase 7 — Features and Matching
• Phase 8 — Object Detection
• Phase 9 — Camera Calibration and Homography
• Phase 10 — Video I/O