Conventions

These conventions are used throughout the workspace. They are not optional and should not change silently.

Coordinate systems

• Image pixels: origin at top-left, x increases right, y increases down.
• Grid coordinates: i increases right, j increases down.
• Grid indices in detections are corner indices (intersections), not square indices, unless explicitly stated otherwise.

Homography and quad ordering

• Quad corner order is always TL, TR, BR, BL (clockwise).
• The ordering must match in both source and destination spaces.
• Never use self-crossing orders like TL, TR, BL, BR.

Sampling and pixel centers

• Warping and sampling should be consistent about pixel centers.
• When in doubt, treat sample locations as (x + 0.5, y + 0.5) in pixel space.

Orientation angles

• ChESS-style corner orientations are in radians and defined modulo pi (not 2*pi).
• Orientation clustering finds two dominant directions and assigns each corner to cluster 0 or 1, or marks it as an outlier.

Marker bit conventions

• Marker codes are packed in row-major order.
• Black pixels represent bit value 1.
• Border width is defined in whole cells (border_bits).

If you introduce new algorithms or data structures, document any additional conventions in the relevant crate chapter.