This example creates a point ROI and uses the setPositionConstraintFcn method to confine ROI creation and movement to within the boundaries of the underlying image.

imshow('cell.tif')
h = impoint(gca,20,60);
% Create a position constraint function.
x = get(gca,'XLim');
y = get(gca,'YLim');
fcn = makeConstrainToRectFcn('impoint',x,y);;
% Register the constraint function with the ROI.
setPositionContraintFcn(h,fcn);
% Retrieve the handle of the current position constraint function.
fcn = getPositionContraintFcn(h);

With the new ROIs, there is no equivalent to getting a handle to the current position constraint function. The new ROIs use the DrawingArea property to specify the limits of the area where you can create and move an ROI. For example, this code creates a 10-pixel margin inside the image boundary where you cannot draw or move the ROI.

imshow('cell.tif')
h = drawpoint(gca,'Position',[20 60])
[height width] = size(I); %Get image dimensions
h.DrawingArea = [10,10,(width-20),(height-20)];