How to block possibility to edit/drag impoly in matlab?

问题

I create a polygon on image_area in matlab. I used impoly. But after creation polygon. I need to block possibility to move and drag impoly (ROI is already created). I don't know how I should do it ?

I would appreciate for any help please.

回答1:

You can set the makeConstrainToRectFcn such that it is a rectangle encompassing your ROI, then whenever you try to move the latter it won't work. You can also, after creating the ROI, set the setVerticesDraggable method to false in order to prevent vertices from being dragged.

Sample code (adapted from example by the Mathworks):

clc
clear

figure
imshow('gantrycrane.png');
h = impoly(gca, [188,30; 189,142; 93,141; 13,41; 14,29]);

%// Get currentposition
Pos = getPosition(h);

%// Prevent draggable vertices
setVerticesDraggable(h,0);

%// Set up rectangle to prvent movement of ROI
fcn = makeConstrainToRectFcn('impoly', [min(Pos(:,1)) max(Pos(:,1))], [min(Pos(:,2)) max(Pos(:,2))]);

%// Apply function
h.setPositionConstraintFcn(fcn);

which results in this kind of situation (with red rectangle for illustration):

来源：https://stackoverflow.com/questions/38377867/how-to-block-possibility-to-edit-drag-impoly-in-matlab