uiselectboxes

R2026b

Select bounding box ROIs from image

Since R2026a

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Syntax

bboxes = uiselectboxes(hImage)
bboxes = uiselectboxes(hImage,Color=boxColor)

Description

bboxes = uiselectboxes(hImage) enables you to interactively select rectangular bounding box ROIs on the displayed image hImage.

bboxes = uiselectboxes(hImage,Color=boxColor) specifies the color of created bounding box ROI boundaries.

example

Examples

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Open Live Script

Load an image containing objects to count into the workspace.

I = imread("coins.png");

Display the image using the imageshow function.

hImage = imageshow(I);

To interactively define bounding box ROIs on the image, use the uiselectboxes function. Click a start point in the image and drag boxes around the desired objects. Click Accept in the top-right corner of the figure window when you are satisfied with your selections.

bboxes = uiselectboxes(hImage)
bboxes = 4×4

    195.4484     28.4718    69.5974    63.5455
    321.0263    101.0952    55.9805    58.2500
    224.9516    116.2251    65.0584    61.2760
    165.1886     85.9653    55.2240    52.1980

This GIF shows how to interactively select bounding boxes by creating and dragging the boxes to different positions on the image.

Extract the patch tiles from the image using the extractpatches function.

tiles = extractpatches(I,bboxes)
tiles = 4×1 cell array
    64×70 uint8
    58×56 uint8
    62×65 uint8
    52×55 uint8

Display the bounding boxes defining the image patches overlaid on the image using the insertShape function.

annotatedImage = insertShape(I,"rectangle",bboxes,"LineWidth",3);
imshow(annotatedImage)

Input Arguments

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Input image object, specified as an Image object. To create an Image object, use the imageshow function. The image must be RGB or grayscale.

Bounding box boundary color, specified as an RGB triplet, hexadecimal color code, or a short or long color name. For a custom color, specify an RGB triplet or a hexadecimal color code.

  • An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]. For example, [0.4 0.6 0.7].

  • A hexadecimal color code is a string scalar or character vector that starts with a hash symbol (#) followed by three or six hexadecimal digits, which can range from 0 to F. The values are not case sensitive. Therefore, the color codes "#FF8800", "#ff8800", "#F80", and "#f80" are equivalent.

Output Arguments

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Axis-aligned rectangular bounding box ROIs, returned as an M-by-4 numeric matrix. M is the number of bounding box ROIs. Each row of the matrix represents a bounding box, returned as a 4-element row vector, and is of the form [x y w h], where:

  • x and y specify the upper-left corner of the rectangle.

  • w specifies the width of the rectangle, which is its length along the x-axis.

  • h specifies the height of the rectangle, which is its length along the y-axis.

Version History

Introduced in R2026a

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See Also

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