This module compresses a graylevel image (fimage) using a uniform scalar
 quantization algorithm\index{quantization!scalar}. 

Compress is the output compressed file. Notice that the list 
of quantization symbols is arithmetically encoded using the 
{\em arithm\_encode2} module (see the documentation of this module 
for further details). 

QantizedImage is the quantized image, which can be reconstructed 
from Compress. 

The -h option indicates that only a reduced header (not including 
the dimensions of image) should be inserted at the beginning 
of the Compress file. 

The -n option specifies the number of steps for the quantization. 
If we call $m$ and $M$ respectively the minimum and the maximum gray level 
values in Input, then the stepsize is computed so that $m$ and $M$ fall 
in the two extremal cells. 

The -s option specifies the stepsize for the quantization. Once again, 
the number of steps is then computed in order that $m$ and $M$ fall 
in the two extremal cells. Note that the -n and -s options are mutually 
exclusive. 

The -c option forces the quantization grid to contain 0. Thus 0 
is a quantization step. 
