User`s guide

R2008a
15-2
Create High Dynamic Range (HDR) Images and Write Them to Files
Create a high dynamic range image from a group of low dynamic range images using
the new makehdr function. The low dynamic range images must be spatially registered.
You can write the HDR image to a file using the hdrwrite function. These functions
complement the hdrread and tonemap functions introduced in R2007b.
Measure Properties of Regions in Grayscale Images
The regionprops function now accepts grayscale images as an input parameter, returning
measurements based on the values of pixels in specified regions. Using regionprops,
you can obtain measurements of regions in the image such as the maximum, minimum,
and mean intensities in the region, and the weighted centroid.
Display Very Large Images by Subsampling
You can now display very large images from TIFF files by using the imshow function's
new 'Reduce' parameter. When you specify this parameter, imshow displays a
subsampled version of the image. imshow determines the subsampling factor by
considering the size of the image and the reduction required to fit the image on your
screen. The 'Reduce' parameter makes it possible to view very large images in
their entirety that could not previously be displayed. Note, however, that the image
subsampling that is performed reduces that amount of image data displayed.
Enhancements to ROI Tools
The toolbox includes several functions that enable the definition of regions of interest of
various shapes: impoint, imline, impoly, imrect, and imfreehand. These ROI tools
have several enhancements:
ROI Tools Reimplemented as MATLAB Classes
The ROI tools have been reimplemented as MATLAB classes. This change does not affect
how the ROI tools function; they function identically to their previous implementation.
The documentation uses the MATLAB functional syntax descriptions rather than the dot
notation. That is, the documentation shows how to call the class methods specifying a
handle to the object as the first argument, method(h,...). Note, however, that you can
still use the dot notation when calling the methods, obj.method(...). In addition, the
iptgetapi function now returns an object of the new class which means that code similar
to the following will continue to work: