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images.roi.Line class

Package: images.roi

Line region-of-interest

Description

The images.roi.Line class creates a linear region-of-interest (ROI) object. You call the draw method of the object to begin drawing the ROI interactively by using your mouse. You can also adjust the size and position of the ROI by using the mouse. The ROI also has a context menu that controls aspects of its appearance and behavior.

The images.roi.Line class is a handle class.

Creation

Description

example

h = images.roi.Line creates an instance of the images.roi.Line class with default properties.

h = images.roi.Line(ax) creates the ROI on the axes specified by ax.

h = images.roi.Line(___,Name,Value) modifies the appearance or behavior of the ROI by specifying values for one or more ROI properties. You can set properties using name-value pairs with or without specifying an axes.

Input Arguments

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Parent of the ROI, specified as an Axes object.

Properties

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Public Properties

ROI color, specified as a MATLAB® ColorSpec (Color Specification).

Example: 'green'

Example: 'g'

Example: [0 1 0]

ROI can be interactively deleted via a context menu, specified as true or false. When the value is true (default), you can delete the ROI via the context menu. To disable this context menu item, set this property to false. When the value is set to false, you can still delete the ROI by calling the delete function, specifying the handle to the ROI as the input.

Area of the axes in which you can interactively place the ROI, specified as one of the values in this table.

ValueDescription
'auto'The drawing area is the current axes limits (default).
'unlimited'The drawing area has no boundary and ROIs can be drawn or dragged to extend beyond the axes limits.
[x,y,w,h]The drawing area is restricted to a rectangular region beginning at (x,y), and extending to width w and height h.

Visibility of the ROI handle in the Children property of the parent, specified as one of the values in this table.

ValueDescription
'on'The object handle is always visible (default).
'off'The object handle is hidden at all times.
'callback' The object handle is visible from within callbacks or functions invoked by callbacks, but not from within functions invoked from the command line.

Interactivity of the ROI, specified as one of the values in this table.

ValueDescription
'all'The ROI is fully interactable (default).
'none'The ROI is not interactable, and no drag points are visible.
'translate'The ROI can be translated (moved) within the drawing area but not reshaped. This value is not available for use with images.roi.Point objects.
'reshape'The ROI can be reshaped but not translated. This value is not available for use with images.roi.Point objects or images.roi.Rectangle objects.

ROI label, specified as a character vector or string. By default, the ROI has no label ('').

Width of the ROI edge, specified as a positive numeric scalar in points. The default value is three times the number of points per screen pixel.

ROI parent, specified as an Axes object. A UIAxes cannot be the parent of the ROI.

Position of the ROI, specified as a 2-by-2 array of the form [x1 y1; x2 y2], where each row specifies the respective end-point of the line segment. You can also set this property by drawing or moving the line.

Selection state of the ROI, specified as the logical value true or false. You can also set this property interactively. For example, clicking on the ROI selects the ROI and sets this property to true. Similarly, if you press Ctrl and click the ROI, the ROI is deselected and the value of this property is set to false.

Color of the ROI when selected, specified as a MATLAB ColorSpec (Color Specification). The intensities must be in the range [0,1]. If 'SelectedColor' is set to 'none', then the value of Color defines the color of the ROI for all states, selected or not.

Example: 'green'

Example: 'g'

Example: [0 1 0]

Color of the ROI stripe, specified as a MATLAB ColorSpec (Color Specification) value. By default, the edge of an ROI is solid colored. If you specify StripeColor, the ROI edge is striped. The striping consists of a combination of the value specified by 'Color' and this value.

Example: 'green'

Example: 'g'

Example: [0 1 0]

Tag to associate with the ROI, specified as a character vector or string. Use the tag value to find the ROI object in a hierarchy of objects using the findobj function.

Context menu, specified as a ContextMenu object. Use this property to display a custom context menu when you right-click the ROI. You can create a custom context menu by using the uicontextmenu function and then configuring context menu properties.

Data to associate with the ROI, specified as any MATLAB data. For example, you can specify a scalar, vector, matrix, cell array, string, character array, table, or structure. MATLAB does not use this data.

ROI visibility, specified as one of the values in this table.

ValueDescription
'on'Display the ROI (default).
'off'Hide the ROI without deleting it. You still can access the properties of an invisible ROI.

Methods

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Events

Event NameTriggerEvent DataEvent Attributes
DeletingROIROI is about to be interactively deleted.event.EventData

NotifyAccess: private

ListenAccess: public

DrawingStartedROI is about to be interactively drawn.event.EventData

NotifyAccess: private

ListenAccess: public

DrawingFinishedROI has been interactively drawn.event.EventData

NotifyAccess: private

ListenAccess: public

MovingROIROI shape or location is being interactively changed.images.roi.ROIMovingEventData

NotifyAccess: private

ListenAccess: public

ROIMovedROI shape or location has been interactively changed.images.roi.ROIMovingEventData

NotifyAccess: private

ListenAccess: public

ROIClickedROI has been clicked. images.roi.ROIClickedEventData

NotifyAccess: private

ListenAccess: public

Examples

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Read an image into the workspace and display it.

I = imread('baby.jpg');
figure
imshow(I)

Create a linear ROI on the image, using the Position property to specify the ROI location. For programmatically created ROIs, if you want the ROI drawn in a specific axes, you must specify that axes as an input argument. Otherwise, an instance of the images.roi.Line class is created but not displayed. In this example, specify the current axes (gca) to draw the ROI on the image in that axes.

h = images.roi.Line(gca,'Position',[100 150;400 650]);

Introduced in R2018b