User`s guide

R2011b
8-2
Parallel Block Processing Now Possible with blockproc
If you have Parallel Computing Toolbox, you can now use a new option in blockproc to
improve performance of block processing tasks. Set the 'UseParallel' argument to
true to use this option.
New bwdistgeodesic Function Computes Geodesic Distance Transform
Use bwdistgeodesic to compute the geodesic distance transform for a binary image.
New graydist Function Computes Gray-Weighted Distance Transform
Use graydist to compute the gray-weighted distance transform of a grayscale image.
New imapplymatrix Function Computes Linear Combination of Color
Channels
The new imapplymatrix function applies a weighted sum to the color planes of an image
for use in color space conversions.
Performance Improvements
Faster Functions
• imhist for large images
• rgb2gray
hdrread Now Correct for Small Values
The hdrread function now returns correct small values. Specifically, the special case
value of (0,0,0,0) now maps to (0,0,0).
Compatibility Considerations
Before R2011b, the value (0,0,0,0) mapped to (0.5740E-41, 0.5740E-41, 0.5740E-41).