User`s guide

R2009a
13-2
Faster, Less Memory-Intensive Workflow for Labeling Regions and
Measuring Their Properties
The bwconncomp function computes connected components for binary images. It uses
significantly less memory and is sometimes faster than bwlabel and bwlabeln.
To extract features from a binary image using regionprops with default connectivity,
just pass BW directly into regionprops (i.e., regionprops(BW)). To compute a label
matrix having more memory-efficient data type (e.g., uint8 versus double), use the
labelmatrix function on the output of bwconncomp.
Multithreaded Implementation of imfilter Function
The imfilter function is now multithreaded.
Efficient Display and Navigation of Very Large Images in imtool
The new rsetwrite function allows you to create a multi-resolution image pyramid (R-
Set) from a large TIFF image file. In previous releases, large images would not open in
imtool, or they did open, but navigation was slow. You can now open your R-Set with
imtool and explore it as you would a standard image.
New Dialog Box for Setting Toolbox Preferences
A new preferences dialog box allows customization of Image Processing Toolbox
preferences. You can access the dialog box via the File menu in the MATLAB desktop,
the File menu in the Image Tool (imtool), or directly from the command line by typing
iptprefs.
A new preference has been added that allows you to specify whether the Overview tool
opens automatically when you launch the Image Tool.
Compatibility Considerations
In previous releases, the Overview tool opened automatically with imtool. The
new default behavior is for the Overview tool to no longer open automatically. If you
would like to revert to the previous behavior you can set this preference via the Image
Processing Preferences dialog box (iptprefs).