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:
**c**haracter,
**d**ouble,
**f**loat,
**i**nt,
**l**ong,
**s**hort. 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.