showShape
Description
showShape(___,
specifies options using one or more namevalue arguments in addition to the input arguments
from the previous syntax. For example, Name=Value
)Color="yellow"
sets the color for
the shapes to yellow.
Examples
Display Detected Objects in Image
Read an image into the workspace.
I = imread("visionteam1.jpg");
Create an aggregate channel features (ACF) people detector.
detector = peopleDetectorACF
detector = acfObjectDetector with properties: ModelName: 'inria100x41' ObjectTrainingSize: [100 41] NumWeakLearners: 2048
Detect people in the image.
[bboxes,scores] = detect(detector,I);
Display the image with a labeled rectangle around each detected person. Display the associated detection score around each detected person.
figure imshow(I) labels = "person:" + scores; showShape("rectangle",bboxes,Label=labels)
Display Bounding Box Around Object in Point Cloud
Read point cloud data into the workspace.
ptCloud = pcread("teapot.ply");
Display the point cloud data.
figure pcshow(ptCloud) xlabel("X") ylabel("Y") zlabel("Z")
Define a cuboid and display it in green with an opacity of 0.5
.
pos = [0.3753 0 1.65 6 4 3 0 0 0]; showShape("cuboid",pos,Color="green",Opacity=0.5)
Visualize Cuboid Around Moving Object in Point Cloud Stream
Read point cloud data into the workspace.
ptCloud = pcread("teapot.ply");
Define a rotation matrix and 3D transform to rotate the point cloud, and an associated cuboid, by 5 degrees.
rot = 5; R = [ cosd(rot) sind(rot) 0 0; ... sind(rot) cosd(rot) 0 0; ... 0 0 1 0; ... 0 0 0 1]; tform = affine3d(R);
Compute the x and y rendered limits of the point cloud, to ensure that you do not clip the point cloud during rotation.
pcLimits = abs([ptCloud.XLimits ptCloud.YLimits]); maxLimit = max(pcLimits);
Add a margin to the plot to prevent the rotation from clipping the cuboid.
margin = 1; maxLimit = maxLimit + margin; xlimits = [maxLimit maxLimit]; ylimits = [maxLimit maxLimit]; zlimits = ptCloud.ZLimits;
Create a player for visualizing the point cloud.
player = pcplayer(xlimits,ylimits,zlimits);
Customize the player axes labels.
xlabel(player.Axes,"X (m)"); ylabel(player.Axes,"Y (m)"); zlabel(player.Axes,"Z (m)");
Define a cuboid around the point cloud.
cuboidPosition = [0.3753 0 1.65 6 4 3 0 0 0];
Define the output view for a cuboid rotation. Use the same limits as the player so that the view does not clip the cuboid. Then, display the rotated point cloud and cuboid.
gridSize = [1 1 1]; ref = imref3d(gridSize,xlimits,ylimits,zlimits); for i = 1:round((360/rot)) % Rotate the point cloud. ptCloud = pctransform(ptCloud,tform); % Rotate the cuboid. cuboidPosition = bboxwarp(cuboidPosition,tform,ref); % Show the rotated point cloud data. view(player,ptCloud) % Show the rotated cuboid. showShape("cuboid",cuboidPosition, ... Parent=player.Axes, ... Color="green", ... Opacity=0.5) % Use drawnow to synchronize the point cloud and shape visualizations. drawnow end
Input Arguments
shape
— Type of shape
"rectangle"
 "line"
 "polygon"
 "circle"
 "cuboid"
 "projectedcuboid"
 "ellipse"
Type of shape, specified as "rectangle"
,
"line"
, "polygon"
, "circle"
,
"cuboid"
, "projectedcuboid"
, or
"ellipse"
.
Data Types: char
position
— Positions and sizes of shapes
matrix  vector  cell array
Position of shape, specified according to the type of shape, as described in the table.
Shape  Position  Definition 

rectangle  For one or more axisaligned rectangles, specify as an Mby4 numeric matrix, where each row specifies a rectangle of the form $$\left[\begin{array}{cccc}x& y& width& height\end{array}\right]$$.
$$\left[\begin{array}{cccc}{x}_{1}& {y}_{1}& widt{h}_{1}& heigh{t}_{1}\\ {x}_{2}& {y}_{2}& widt{h}_{2}& heigh{t}_{2}\\ \vdots & \vdots & \vdots & \vdots \\ {x}_{M}& {y}_{M}& widt{h}_{M}& heigh{t}_{M}\end{array}\right]$$
 
For one or more rotated rectangles, specify in spatial coordinates as an Mby5 numeric matrix, where each row specifies a rotated rectangle of the form [xctr yctr w h yaw].
 
cuboid  For one or more cuboids, specify in spatial coordinates as an Mby9 numeric matrix where each row specifies a cuboid of the form [xctr yctr zctr xlen ylen zlen xrot yrot zrot], where


circle  For one or more circles, specify spatial coordinates as an Mby3 numeric matrix, where each row specifies a circle of the form [xctr yctr radius].
$$\left[\begin{array}{ccc}xct{r}_{1}& yct{r}_{1}& radiu{s}_{1}\\ xct{r}_{2}& yct{r}_{2}& radiu{s}_{2}\\ \vdots & \vdots & \vdots \\ xct{r}_{M}& yct{r}_{M}& radiu{s}_{M}\end{array}\right]$$
 
ellipse  For one or more ellipses, specify in spatial coordinates as an Mby5 matrix, where each row specifies an ellipse of the form [xctr yctr major minor yaw]


 For one or more lines, specify spatial coordinates using one of these formats to specify a single line with connected endpoints, multiple lines with the same number of endpoints, or multiple lines with different numbers of endpoints.
 
polygon  For one or more polygons, specify in spatial coordinates as an Mby1 cell array, where each cell contains an Lby2 matrix of [x y] vertex locations or a 1by2L vector of consecutive vertex locations of the form [x_{1}, y_{1}, x_{2},y_{2}, … x_{L},y_{L} ].


projectedcuboid  For one or more projected cuboids, specify in spatial coordinates as an 8by2byM array or an Mby8 matrix, where M is the number of projected cuboids. When specified as an 8by2byM array, each row must contain the [x y] location of a projected cuboid vertex. The vertices connect to form a cuboid with six faces. The order of the input vertices must match the order shown in the diagram. When specified as an Mby8 matrix, each row specifies the dimensions of the frontfacing and rearfacing sides of a projected cuboid in the form, [x1 y1 w1 h1 x2 y2 w2 h2], where [x1 y1] and [x2 y2] specify the upperleft coordinates of the frontfacing and rearfacing sides, respectively, and [w1 h1] and [w2 h2] specify the corresponding widths and heights. 

NameValue Arguments
Specify optional pairs of arguments as
Name1=Value1,...,NameN=ValueN
, where Name
is
the argument name and Value
is the corresponding value.
Namevalue arguments must appear after other arguments, but the order of the
pairs does not matter.
Example: showShape("rectangle",bboxes,Color="yellow")
sets the color
for the shapes to yellow.
Before R2021a, use commas to separate each name and value, and enclose
Name
in quotes.
Example: showShape("rectangle",bboxes,"Color","yellow")
sets the
color for the shapes to yellow.
Label
— Shape label
[]
(default)  scalar  Melement vector  Melement cell array of character vectors
Shape label, specified as a scalar, Melement vector, or an Melement cell array of character vectors, where M is the number of shapes.
If the input is a scalar value, then the function applies the label to each shape. If the input is an Melement vector or cell array, then the function applies the unique label to the corresponding shape, using the order in which you specify the shapes to the function.
Color
— Shape color
"green"
(default)  short color name  color name  vector of color names  threecolumn matrix of RGB triplets
Shape color, specified as a short color name, color name, vector of color names, threecolumn matrix of RGB triplets.
The supported colors table lists RGB intensities in the range [0, 1], but you must
specify RGB triplets in the range of your selected data type. For example, if
specifying this argument as a matrix of uint8
values, you must
convert each intensity value to the range [0, 255]. To convert the listed intensity
values to a uint8
data type, use the code
uint8(255*intensity)
, where intensity is an RGB triplet value
listed in the table.
You can specify a different color for each shape or one color for all shapes. To
specify one color for all markers, specify Color
as a color name
or an [R
G
B] vector.
Specification  Format  Example 

Specify one color for all shapes (or markers)  Short color name or color name 

RGB triplet 
 
Specify a color for each shape (or marker)  Vector of color names 

Threecolumn matrix of RGB triplets  [1 0 0 0 1 1 1 0 1 1 1 1] 
This table lists the supported shape colors.
Color Name  Short Name  RGB Triplet  Appearance 

"red"  "r"  [1 0 0]  
"green"  "g"  [0 1 0]  
"blue"  "b"  [0 0 1]  
"cyan"  "c"  [0 1 1]  
"magenta"  "m"  [1 0 1]  
"yellow"  "y"  [1 1 0]  
"black"  "k"  [0 0 0]  
"white"  "w"  [1 1 1] 
Data Types: logical
 uint8
 uint16
 int16
 double
 single
 cell
Opacity
— Opacity of shape fill
0
(default)  scalar in range [0 1]  Melement vector of values in range [0 1]
Opacity of the shape fill, specified as a scalar or Melement
vector of numeric values in the range [0 1], where M is the number
of shapes. To use the same opacity for all shapes, specify a scalar opacity value. For
a fully opaque shape fill, specify Opacity
as
1
.
Parent
— Output axes
gca
(default)  Axes
graphics object
Output axes, specified as an Axes
graphics object. For more
information on Axes object properties, see Axes Properties.
LineColor
— Shape border line color
"auto"
(default)  one or more RGB triplets  one or more color names or short color names
Shape border line color, specified as a short color name, color name, vector of color names, threecolumn matrix of RGB triplets.
The supported colors table lists RGB intensities in the range [0, 1], but you must
specify RGB triplets in the range of your selected data type. For example, if
specifying this argument as a matrix of uint8
values, you must
convert each intensity value to the range [0, 255]. To convert the listed intensity
values to a uint8
data type, use the code
uint8(255*intensity)
, where intensity is an RGB triplet value
listed in the table.
You can specify a different color for each shape or one color for all shapes. To
specify one color for all markers, specify LineColor
as a color
name or an [R
G
B] vector.
LineWidth
— Border line width
"auto"
(default)  positive scalar integer  Melement vector of positive integers
Border line width in pixels, specified as a positive integer or an Melement vector of positive integers, where M is the number of shapes. To use the same line width for all shapes, specify a scalar positive integer. Otherwise, specify an Melement vector of positive integers.
LineOpacity
— Border line opacity of shape
0
(default)  Melement vector of values in the range [0 1]
Border line opacity of shape, specified as a scalar or
Melement vector of numeric values in the range [0 1], where
M is the number of shapes. To use the same opacity for all
shapes, specify a scalar opacity value. For a fully opaque shape fill, specify
Opacity
as 1
.
LabelTextColor
— Label text color
"black"
(default)  one or more RGB triplets  one or more color names or short color names
Label text color, specified as a short color name, color name, vector of color names, threecolumn matrix of RGB triplets.
The supported colors table lists RGB intensities in the range [0, 1], but you must
specify RGB triplets in the range of your selected data type. For example, if
specifying this argument as a matrix of uint8
values, you must
convert each intensity value to the range [0, 255]. To convert the listed intensity
values to a uint8
data type, use the code
uint8(255*intensity)
, where intensity is an RGB triplet value
listed in the table.
You can specify a different color for each label or one color for all labels. To
specify one color for all markers, specify LabelTextColor
as a
color name or an [R
G
B] vector.
LabelOpacity
— Label opacity
0
(default)  Melement vector of values in the range [0 1]
Label opacity of shape, specified as a scalar or Melement
vector of numeric values in the range [0 1], where M is the number
of shapes. To use the same opacity for all labels, specify a scalar opacity value. For
a fully opaque shape fill, specify Opacity
as
1
.
LabelFont
— Label font
"Helvetica"
(default)  "FixedWidth"
 supported font
Label font, specified as "FixedWidth"
or a font that your
system supports. To display and print text properly, you must select a font that your
system supports. If you select an unsupported font, the function returns an error. If
you specify "FixedWidth"
, the function uses the font specified by
the FixedWidthFont
property of the Root Properties object. The fixedwidth font relies on the value of
get(0,"FixedWidthFontName")
.
LabelFontSize
— Label font size
12
(default)  positive scalar
Label font size in points, specified as a positive scalar.
ShowOrientation
— Original orientation indicator
false
or 0
(default)  true
or 1
Original orientation indicator, specified as a numeric or logical
1
(true
) or 0
(false
). A value of 1
(true
) displays the original orientation of the rotated rectangle
by using an arrow annotation on the bounding box. The original orientation is defined
as a zero rotation angle. A value of 0
(false
)
does not show the arrow annotation.
This argument applies only when Shape
describes a rotated
rectangle or an ellipse.
Data Types: logical
 integer
Version History
Introduced in R2020bR2024b: Support for ellipse shape
Added support for "ellipse"
to visualize one or more ellipses on top
of an image or on video data.
R2024b: Default value for orientation indicator changed from true
to false
Starting in R2024b, the default value for the ShowOrientation
namevalue argument will be false
.
R2023b: Rotated rectangle support for bounding box
You can specify a rotated rectangle bounding box using the form [xctr yctr width height yaw].
R2022b: Visualize projected cuboids
Added support to visualize projected cuboids.
R2022a: Bounding Box Coordinates: Data augmentation for object detection using spatial coordinates
The bboxresize
,
bboxcrop
,
bboxwarp
, and
showShape
functions assume the input bounding box coordinates for axisaligned rectangles are
specified in spatial coordinates and return the transformed bounding boxes in spatial
coordinates.
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