bboxresize

Resize bounding boxes

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Syntax

bboxB = bboxresize(bboxA,scale)

Description

example

bboxB = bboxresize(bboxA,scale) resizes bounding boxes in bboxA by the amount specified by scale.

Examples

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Open Live Script

Read an image.

I = imread('peppers.png');

Define bounding boxes and labels.

bboxA = [
    410 230 100 90
    186 78  80  60
    ]
bboxA = 2×4

   410   230   100    90
   186    78    80    60


labelsA = [
    "garlic"
    "onion"
    ];

Resize the image and the bounding boxes.

scale = 1.5; 
J = imresize(I,scale); 
bboxB = bboxresize(bboxA,scale);

Display the results.

figure
I = insertObjectAnnotation(I,'Rectangle',bboxA,labelsA);
J = insertObjectAnnotation(J,'Rectangle',bboxB,labelsA);
imshowpair(I,J,'montage')

Input Arguments

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Bounding boxes, specified as an M-by-4, M-by-5, or M-by-9 nonsparse numeric matrix of M bounding boxes. Each row, M, of the matrix defines a bounding box as either an axis-aligned rectangle, a rotate rectangle, or a cuboid. The table below describes the format of the bounding boxes.

Bounding BoxRowDescription
Axis-aligned rectangle[xmin, ymin, width, height]This type of bounding box is defined in pixel coordinates as an M-by-4 matrix representing M bounding boxes
Rotated rectangle[xcenter, ycenter, width, height, yaw]This type of bounding box is defined in spatial coordinates as an M-by-5 matrix representing M bounding boxes. The xcenter and ycenter coordinates represent the center of the bounding box. The width and height elements represent the length of the box along the x and y axes, respectively. The yaw represents the rotation angle in degrees. The amount of rotation about the center of the bounding box is measured in the clockwise direction.
Cuboid[xcenter, ycenter, zcenter, width, height, depth, rx, ry, rz]Defined in spatial coordinates as an M-by-9 matrix representing M bounding boxes. The xcenter, ycenter, and ycenter coordinates represent the center of the bounding box. The width and height elements represent the length of the box along the x and y axes, respectively. The rx,ry, and rz rotation angles are in degrees about the cuboid center. The rotation is positive in the clockwise direction, with respect to the positive direction of the axis.

Rotation matrices are computed assuming ZYX order Euler angles [rx, ry, rz].

Scale, specified as a scalar or a row vector. When you specify a scalar, the function applies the same scale factor to the height and width of the bounding boxes in bboxA. When you specify a row vector, the function applies the factor in the first element of the vector to resize the height and the second element to resize the width of the bounding boxes.

Output Arguments

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Warped bounding boxes, returned as an M2-by-N matrix of M2 bounding boxes. The number of bounding boxes returned is less than the number of bounding boxes in the input. Each row, M2, of the matrix defines one bounding box of the same type as the input bboxA.

See Also

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Introduced in R2019b

Computer Vision Toolbox Documentation
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