bbox2points

Convert rectangle to corner points list

Syntax

points = bbox2points(rectangle)

Description

points = bbox2points(rectangle) converts the input rectangle, specified as [x y width height] into a list of four [x y] corner points. The rectangle input must be either a single bounding box or a set of bounding boxes.

Examples

Convert Bounding Box to List of Points and Apply Rotation

Define a bounding box.

bbox = [10,20,50,60];

Convert the bounding box to a list of four points.

points = bbox2points(bbox);

Define a rotation transformation.

theta = 10;
tform = affine2d([cosd(theta) -sind(theta) 0; sind(theta) cosd(theta) 0; 0 0 1]);

Apply the rotation.

points2 = transformPointsForward(tform,points);

Close the polygon for display.

points2(end+1,:) = points2(1,:);

Plot the rotated box.

plot(points2(:,1),points2(:,2), '*-');

Input Arguments

rectangle — Bounding box

4-element vector | M-by-4 matrix

Bounding box, specified as a 4-element vector, [x y width height], or a set of bounding boxes, specified as an M-by-4 matrix.

Data Types: single | double | int16 | int32 | uint16 | uint32

Output Arguments

points — Rectangle corner coordinates

4-by-2 matrix | 4-by-2-by-M array

List of rectangle corners, returned as a 4-by-2 matrix of [x,y] coordinates, or a 4-by-2-by-M array of [x,y] coordinates. The output points for the rectangle are listed counterclockwise starting from the upper-left corner.

• For a single input bounding box, the function returns the 4-by-2 matrix.

• For multiple input bounding boxes, the function returns the 4-by-2-M array for M bounding boxes.

Data Types: single | double | int16 | int32 | uint16 | uint32

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

Version History

Introduced in R2014b