User`s guide

16-3
returns a low-pass filtered version of the image, half the size of the original image. If you
specify the 'expand' parameter, impyramid returns a filtered image twice the size of the
original image. impyramid uses convolution with a Gaussian filter kernel to produce the
images.
Enhanced ROI Definition Behavior for imcrop, roifill, and roipoly
The imcrop, roifill, and roipoly functions now let you define an ROI and then adjust the
size and position of the ROI interactively using the mouse. In previous releases, these
functions supported the interactive definition of ROIs, but only gave you one chance at
the definition. Now, when you are satisfied with the size and shape of the ROI, double-
click to perform the cropping, filling, or mask creation operation.
Compatibility Considerations
In previous releases, when defining a polygonal ROI using roipoly, pressing
Backspace deleted the most recent vertex you had defined in the polygon. With this
release, pressing Backspace deletes the entire polygon. To delete an individual vertex,
move the pointer over the vertex, right-click to view the vertex context menu, and then
choose Delete Vertex.
New Modular Interactive GUI-building Tools
The set of modular interactive tools now includes functions to display a file chooser dialog
box and write data to a file (imsave). The toolbox also includes a function (imputfile) that
displays the file chooser dialog box and returns the user's selections.
New Programmable ROI Tools
The set of programmable ROI creation functions provided by the toolbox now includes
three additional shapes:
• Polygons (impoly)
• Ellipses (imellipse)
• Freehand shapes (imfreehand)
The toolbox already includes ROI creation functions to create points, lines, and
rectangles.