ISIS 3 Application Documentation
Normalize columns or lines in a cube
Description
The program accomplishes the fairly straightforward task of taking an input
cube and outputting normalized values. These values may be represented as
a table, PVL (parameter value language), or an entire output cube.
Normalization may be done with respect to lines or with respect to columns.
If the user were to normalize by line, the program would take a pass through
the data in order to determine statistics for each line. Cubenorm will then
pass through each pixel again and normalize each one based on the line in
which that pixel is located.
The normalization itself may be thought of as applying either a multiplicative
correction or a subtractative correction. Consider the average of a column
of data. Each pixel may be normalized by subtracting a normalization factor
or multiplying by a normalization factor. Additionally, the user may decide
to use a normalization factor based on the median instead of the average.
Categories
Applications
History
Eric Eliason  20040615 
Original version (as colnorm)

Drew Davidson  20050706 
Added options for subtractative corrections

Drew Davidson  20050706 
Added process by line option and rename to cubenorm

Drew Davidson  20050706 
Modified unit test to take new options in to account

Jeff Anderson  20050909 
Major reworking and bug fixes

Drew Davidson  20051024 
Specialized to run using input files.

Kris Becker  20070111 
Incorporate UA cubenorm_plus version functionality

Christopher Austin  20080317 
Changed a single valid pixel's RowCol's Standard Deviation to 0 instead of
Isis:Null. When reading in a table file, all Standard Deviations less
than 0 are considered 0.

Steven Lambright  20080513 
Removed references to CubeInfo

Steven Koechle  20080902 
Fixed check in getstats method that sees whether you are processing by
line or column.

Steven Lambright  20090730 
Removed redundancy of having static global variables


Parameter Groups
Files and options
Name

Description

FROM 
Input cube

TO 
Optional output cube

STATS 
Optional stats file

FORMAT  Format type of STATS file (TABLE or PVL) 
Optional Statistics Source
Name

Description

STATSOURCE  Input source of statistics to apply to FROM cube 
FROMSTATS  Optional statistics input file source 
Normalization options
Name

Description

DIRECTION  Direction in which statistics and operations operate 
NORMALIZER 
Apply normalization using average or median

MODE 
Apply coefficients through subtraction or division

PRESERVE  Preserve the input image median/average 

Files and options:
FROM
Description
Use this parameter to select input file
Type
 cube 
File Mode
 input 
Filter

*.cub

Files and options:
TO
Description
Output file with input columns divided by the column average
Type
 cube 
File Mode
 output 
Pixel Type
 real 
Internal Default

No Output file will be created

Files and options:
STATS
Description
Statistical output of each column
(band #, column #, valid pixels, average, median, std, min, max)
Type
 filename 
File Mode
 output 
Internal Default

No Output file will be created

Optional Statistics Source:
STATSOURCE
Description
This option is intended to be used when the statistics come from
a source other than the input cube (default). cubenorm initial
derives all its statistics from the input cube and applies it as
specified by the user in the same run. This works for most
conditions but does not works so well with abrupt changes
in brightness such as craters or poles.
With this option, it is now possible to have the statistics come
a file in a format compatable with the STATS output file. This can
be a TABLE or PVL formatted input file. This allows statistics
from other cubenorm runs to be used as input statistics source.
It also allows intermediate processing on the FROM stats to
apply additional smoothing or culling techniques.
Type
 string 
Default
 CUBE 
Option List:

Option 
Brief 
Description 
CUBE  Statistics are computed from FROM input cube 
This is the old behavior. The statistics are computed from
the input cube as specified by the FROM parameter. They
are also applied to the TO file if specifed in the same run.
Exclusions

TABLE  Statistics are provided in FROMSTATS in TABLE format 
This option requires a filename in FROMSTATS with TABLE formatted
data. This format is the same format as is generated in the STATS
output file.

PVL  Statistics are provided in FROMSTATS in PVL format 
This option requires a filename in FROMSTATS with PVL formatted
data. This format is the same format as is generated in the STATS
output file.


Optional Statistics Source:
FROMSTATS
Description
This optional file provides the statistics that are applied to the input
FROM file. Its format must be TABLE or PVL and consistant with
the STATS file output format.
If this option is utilized, the statistics gathering step is bypassed.
Type
 filename 
File Mode
 input 
Filter
 *.txt 
Normalization options:
DIRECTION
Description
This is the direction in which normalization occurs. If the user chooses
to process by column, they intend to take in an entire column of data
and normalize based on the average or median of that column for each
pixel in that column. If they choose to process by line, they intend to
do the same for each pixel, but with respect to lines.
Type
 string 
Default
 COLUMN 
Option List:

Option 
Brief 
Description 
COLUMN  Normalize columns 
Gather statistics by moving left to right through the cube

LINE  Normalize lines 
Gather statistics by moving from top to bottom through the cube


Normalization options:
NORMALIZER
Description
This option is used to select if column or line is normalized using its average or median
Type
 string 
Default
 MEDIAN 
Option List:

Option 
Brief 
Description 
MEDIAN  Use column/line median when normalizing 
This option will use the median of the column/line when normalizing each column/line

AVERAGE  Use column/line average when normalizing 
This option will use the average of the column/line when normalizing each column/line


Normalization options:
MODE
Description
This option is used to select select how normalization coefficients are applied, either subtracting or dividing by
the average or median.
Type
 string 
Default
 DIVIDE 
Option List:

Option 
Brief 
Description 
DIVIDE  Divide column/row by its median/average 
This option will divide each column (or row) by its normalizer (median or average).

SUBTRACT  Subtract median/average from column/row 
This option will subtract the normalizer (median or average) from each column (or row).


Normalization options:
PRESERVE
Description
This option is used to preserve the average/median of the input image. If turned off, the output image
average of the data will be one (unity) for the DIVIDE mode or zero for the SUBTRACT mode.
Type
 boolean 
Default
 TRUE 