SIVP Toolbox
Last update : September, 2008
impyramid  Image pyramid reduction and expansion
Calling Sequence
 imout = imresize(imin, direction)
Parameters

imin:
An image which will be downsampled or upsampled.

direction:
Can be 'reduce' or 'expand'. If direction is 'reduce', impyramid computes a Gaussian pyramid reduction of imin by one level. If direction is 'expand', impyramid computes a Gaussian pyramid expansion of imin by one level. Gaussian 5x5 filter is currently supported.

imout:
The output reduced or expanded image.
Description
imout=impyramid(imin,direction) computes a Gaussian pyramid reduction or expasion of imin by one level. Direction can be 'reduce' or 'expand'. If imin is mxn and direction is 'reduce', then the size of imout is ceil(m/2)xceil(n/2). If direction is 'expand', then the size of imout is (2xm)x(2xn).
Examples
Compute a fourlevel multiresolution pyramid of the 'lena' image.
im0 = imread(SCI + '/contrib/sivp/images/lena.png');
im1 = impyramid(im0, 'reduce');
im2 = impyramid(im1, 'reduce');
im3 = impyramid(im2, 'reduce');
imshow(im0);
imshow(im1);
imshow(im2);
imshow(im3);
Authors

Jia Wu <jiawu83[at]gmail.com>
Availability
The latest version of SIVP can be found at
http://sivp.sourceforge.net
See Also
imresize,