wavelet — perform a haar wavelet decomposition/reconstruction
wavelet [-1 ] [-2 ] [-d ] [-r ] [-# channels] [ -t [ c | d | f | i | l | s ]] [-w width] [-n scanlines] [-s squaresize] [-S square_out_size] [-W width_out] < file > wavelet
The wavelet command will perform Haar wavelet decomposition or reconstruction transforms on the input dataset. The command line options are:
-d
perform decomposition.
-r
perform reconstruction.
-1
perform a 1-dimensional (horizontal) transform.
-2
perform a 1-dimensional (interleaved horizontal and vertical) transform.
-# channels
Indicates the number of values in each sample point. For example, to perform
a transform on a
pix(5)
file properly, specify "-# 3". This causes the red, green and blue channels
to be transformed individually.
-t {cdfils}
specifies the data type of the input, and hence the data type in which the
wavelet calculations will be performed.
The letters each stand for the first
character of the C programming language data type:
character,
double,
float,
int,
long,
short.
Note that if lossless decomposition
and reconstruction are desired, then data sets should be converted to the next
larger data type before being processed.
-w width
Specify the number of samples per scanline.
-n scanline
Specify the number of scanlines in the dataset
-s squaresize
Specify both width and scanlines simultaneously (square image).
-W width_out
Specifies the width of the output image. Normally this is 1 for a full
decomposition/reconstruction. You may specify a width at which decomposition or reconstruction
should stop. This number should be a power of 2. The result will be an
"average" image of the specified size, with the remainder of the original
data width converted to "detail" coefficients. See also: -R
-R avg_size
Resumes a transform that left off with an average image of avg_size.
-S square_out_size
This is the same as the
-W
option. It implies the square size for a 2D decomposition limit.
The command
decompose -# 3 < img.pix | pix-fb
will display the horizontal decomposition of the file img.pix.
The command
decompose -# 3 -s 1024 -l 64 < img.pix >
will decompose a 1024x1024 image. The decomposition will stop when the
image has been decomposed to 64x64. The output image will thus have a 64x64
version of the original in the lower left corner of the image, with detail
terms in the remainder.