Polyline region of interest
The Polyline
object is a polyline region-of-interest
(ROI).
To draw the ROI, position the cursor on the axes and click and drag to create the shape. As you draw, click to place vertices along the line. Double-click to finish drawing the polyline. For more information about using this ROI, including keyboard shortcuts, see Tips.
To create a Polyline
object, use the
images.roi.Polyline
creation function. After creating the object, call
the draw
object
function to begin drawing. As a convenience, you can also use the drawpolyline
function to create a Polyline
ROI. The drawpolyline
function creates the ROI object and automatically calls the draw
object
function.
creates an
instance of the roi
= images.roi.Polylineimages.roi.Polyline
class with default
properties.
creates the ROI in the axes specified by roi
= images.roi.Polyline(ax
,___)ax
.
sets properties using
name-value pairs. For example, roi
= images.roi.Polyline(___,Name,Value
)images.roi.Polyline('Color','y')
sets
the color of the Polyline
object to yellow. You can specify multiple
name-value pairs. Enclose each property name in single quotes.
addlistener | Create event listener bound to event source |
beginDrawingFromPoint | Begin drawing ROI from specified point |
bringToFront | Bring ROI to front of Axes stacking order |
createMask | Create binary mask image from ROI |
draw | Begin drawing ROI interactively |
reduce | Reduce density of points in ROI |
wait | Block MATLAB command line until ROI operation is finished |
The ROI supports the following interactivity, including keyboard shortcuts.
Behavior | Keyboard shortcut |
---|---|
Make drawn line snap at 15 degree angles. | Hold the Shift key while drawing. |
Finish drawing the ROI. | Double-click, which adds a final new vertex at the pointer position. Right-click, which adds a final new vertex at the pointer position. Press Enter, which adds a final new vertex at the pointer position.. |
Cancel drawing the ROI. | Press Esc. The function returns a valid ROI object with an
empty Position field. |
Add a new vertex to the ROI. | Position the pointer over the polygon and double-click. You can also position the pointer over the ROI, right-click, and choose Add Vertex. |
Remove a vertex from the ROI. | Position the pointer over the ROI, right-click, and choose Delete Vertex. |
Remove the most recently added vertex but keep drawing. | Press Backspace. The function redraws the line from the previous vertex to the current position of the pointer. You can only back up to the first vertex you drew. |
Resize (reshape) the ROI. | Position pointer over a vertex and then click and drag. Add a new vertex and then click and drag. Remove a vertex and the shape of the ROI adjusts. |
Move the ROI. | Position the pointer over the line, not on a vertex. The pointer changes to the fleur shape. Click and drag the polygon. |
Delete the ROI. | Position the pointer over the line, right-click, and select
Delete Polyline from the context menu. You can also
delete the ROI programmatically using the delete object
function. |
For information about using an ROI in an app created with App Designer, see Using ROIs in Apps Created with App Designer.
AssistedFreehand
| Circle
| Crosshair
| Cuboid
| drawpolyline
| Ellipse
| Freehand
| Line
| Point
| Polygon
| Rectangle