Struct SquareGridHomographyMesh 

pub struct SquareGridHomographyMesh<F: Float = f32> {
    pub min_i: i32,
    pub min_j: i32,
    pub cells_x: usize,
    pub cells_y: usize,
    pub px_per_cell: F,
    pub valid_cells: usize,
    pub rect_width: usize,
    pub rect_height: usize,
    /* private fields */
}

Per-cell homography mesh over a 2D grid.

Maps between a rectified coordinate system (uniform grid spacing) and the original image coordinates, using one homography per grid cell.

Fields

min_i: i32

Minimum grid index (corner space).

min_j: i32

Minimum grid index (corner space).

cells_x: usize

Number of cells (squares) horizontally.

cells_y: usize

Number of cells (squares) vertically.

px_per_cell: F

Rectified pixels per grid cell.

valid_cells: usize

Number of cells that have all 4 corners and a valid homography.

rect_width: usize

Width of the rectified image in pixels.

rect_height: usize

Height of the rectified image in pixels.

Implementations

impl<F: Float> SquareGridHomographyMesh<F>

pub fn from_corners( corners: &HashMap<GridCoords, Point2<F>>, px_per_cell: F, ) -> Result<Self, GridMeshError>

Build per-cell homographies from a grid corner map.

• corners: map from grid index to image position.
• px_per_cell: rectified pixels per grid cell.

Equivalent to Self::from_corners_with_min_singular_value with F::zero() — every cell whose four corners are present and whose homography solves successfully is accepted, regardless of conditioning.

pub fn from_corners_with_min_singular_value( corners: &HashMap<GridCoords, Point2<F>>, px_per_cell: F, min_singular_value: F, ) -> Result<Self, GridMeshError>

Variant of Self::from_corners that skips cells whose homography is ill-conditioned.

A cell is treated as invalid (a “hole”) when the smallest singular value of its 3×3 homography matrix falls below min_singular_value. The threshold is in the same units as the matrix entries; for the standard (grid_corner_space → image_pixels) fit, a threshold around 1e-3 × px_per_cell rejects cells where three of the four corners are nearly collinear in pixel space.

Cells skipped this way are silently ignored, exactly like cells missing one or more corners. The error variant GridMeshError::HomographyFailed is still returned only when the underlying solver fails — a strictly different failure mode from “the solver succeeded but the result is degenerate”.

pub fn rect_to_img(&self, p_rect: Point2<F>) -> Option<Point2<F>>

Map a point in global rectified pixel coordinates to image coordinates.

Returns None if the point lies outside the mesh or the cell is invalid.

pub fn cell_quality(&self, ci: usize, cj: usize) -> Option<HomographyQuality<F>>

Per-cell homography quality, or None when the cell is missing or outside the mesh. Returns the quality even for cells marked invalid by the conditioning gate so callers can introspect why a cell was rejected.

pub fn cell_rect_to_img( &self, ci: usize, cj: usize, p_cell: Point2<F>, ) -> Option<Point2<F>>

Map a point in cell-local rectified coordinates to image coordinates.

• ci, cj: cell indices in 0..cells_x × 0..cells_y
• p_cell: point in [0..px_per_cell]²

pub fn cell_corners_img(&self, ci: usize, cj: usize) -> Option<[Point2<F>; 4]>

Get the 4 image-space corners of a cell (TL, TR, BR, BL order).

Trait Implementations

impl<F: Clone + Float> Clone for SquareGridHomographyMesh<F>

fn clone(&self) -> SquareGridHomographyMesh<F>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<F: Debug + Float> Debug for SquareGridHomographyMesh<F>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.