Module gradient 

Gradient computation for edge refinement. Gradient computation for edge-based quad detection.

Structs

Gradient

Gradient data for a single pixel.

LineSegment

A detected line segment.

Functions

compute_sobel

Compute Sobel gradients for the entire image. Returns a flat array of Gradient structs.

extract_line_segments

Extract line segments from gradient image using a simplified LSD approach. This is a greedy region-growing algorithm on gradient direction.

find_first_quad_from_segments

Find quads by grouping 4 line segments that form a closed quadrilateral.

fit_quad_from_component

Fit a quad from a small component using on-demand gradient computation.

fit_quad_from_gradients

Fit a quad from boundary pixels using gradient direction clustering.