ISIS Application Documentation
Create a flat-field image for line-scan, push-frame, and framing instruments
Description
This program creates flat-field images for line scan, push frame, and framing instruments.
All input cubes should have the same number of samples; any images in the list that do not
have the same number of samples as the first image will not be used. The names of the cube
files used to create the flat-field image must be entered using an ASCII file (FROMLIST) with
one filename per line (any line beginning with a '#' or '//' is treated as a comment). The
specific equation for each camera type is below.
- Line Scan
A frame is a NUMLINES line section of data. The equation for the final single line, single
band, flat field file is:
Mean Calculation:
Sum( Sum(FrameColumn) / Average(Frame) * ValidPixels(FrameColumn) ) /
TotalColumnValidPixels
Median Calculation:
Median(PixelColumn(ValidPixel / Average(Frame)))
- Push Frame
Mean Calculation:
The equation for the final single framelet, single band flat field file is:
Average(
PixelInFramelet1, PixelInFramelet2, PixelInFramelet3, ... )
Median Calculation:
Median(PixelColumn(ValidPixel / Average(Frame)))
- Framing
Mean Calculation:
The equation for the final single framelet, single band flat field file is:
Average(
PixelInCube1, PixelInCube2, PixelInCube3, ... )
Median Calculation:
Median(PixelColumn(ValidPixel / Average(Frame)))
Warning: This program creates potentially large temporary files
Categories
History
| Victor Silva | 2016-09-12 |
Original version, Adapted from Isis version of makeflat.
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|
Parameter Groups
Files
|
Name
|
Description
|
| FROMLIST |
List of input cubes
|
| TO |
Output name prepended to flat field output cubes
|
| EXCLUDE |
Output PVL-formatted file of all excluded files and sections of data
|
Camera Options
|
Name
|
Description
|
| IMAGETYPE |
This is the type of camera which took the image.
|
| NUMLINES |
This is the number of lines to consider when doing statistics
|
| FRAMELETHEIGHT |
This is the height of each framelet in the image.
|
Processing Options
|
Name
|
Description
|
| NORMALIZATION |
Include Normalization Step
|
| STDEVTOL |
This is the number of standard deviations to use as outlier boundary.
|
Normalization Options
|
Name
|
Description
|
| WIDTH_PIXELS |
Width in Pixels from center of image to use for normalization
|
| HEIGHT_LINES |
Height in Lines from center of image to use for normalization
|
|
Files:
FROMLIST
Description
Use this parameter to select the file which contains a list of
cube filenames to be used to create the flat file.
|
Type
| filename |
|
File Mode
| input |
|
Filter
|
*.lis
|
Files:
TO
Description
Output prefix of the flat field cube's name
|
Type
| cube |
|
File Mode
| output |
|
Pixel Type
| real |
Files:
EXCLUDE
Description
Output PVL-formatted file of all excluded files and sections of data.
|
Type
| filename |
|
File Mode
| output |
|
Internal Default
| None |
Camera Options:
IMAGETYPE
Description
The type of camera that captured the input image.
|
Type
| string |
|
Default
| LINESCAN |
|
Option List:
|
|
Option |
Brief |
Description |
| LINESCAN | Line scan camera |
Line scan cameras collect an image a single line of data at a time. This option makes
the flat field a single line of data.
Exclusions
- FRAMELETHEIGHT
- HEIGHT_LINES
Inclusions
|
| PUSHFRAME | Push frame camera |
Push frame cameras collect multiple lines, one framelet, of data at once. This
option makes the flat field a single framelet of data.
Exclusions
Inclusions
|
| FRAMING | Framing camera |
Framing cameras collect an entire cube of data at once. This option makes the
flat field the size of one of the input images.
Exclusions
|
|
Camera Options:
NUMLINES
Description
A single line often does not have enough data in it to perform good tolerance
calculations. The tolerance calculations will be performed on this many lines as
a time, and if found to be invalid, this many lines will be excluded from the output
flat file calculations at a time.
Camera Options:
FRAMELETHEIGHT
Description
Push frame images consist of framelets. The framelet size needs to be
known in order to make a flat field file for a push frame camera.
Processing Options:
NORMALIZATION
Description
If this pre-processing step was not done prior, Makeflat will normalize each pixel by the frame's mean in
order to normalize to 1. You can select image dimensions (height and width in pixels) to use when calculating frame mean.
|
Type
| string |
|
Default
| NO |
|
Option List:
|
|
Option |
Brief |
Description |
| YES |
The normalization process will be applied.
|
The normalization process will be applied to each pixel location
prior to stacking.
Inclusions
- WIDTH_PIXELS
- HEIGHT_LINES
|
| NO |
The normalization process will not be applied.
|
Each pixel location will not be normalized prior to stacking.
Exclusions
- WIDTH_PIXELS
- HEIGHT_LINES
|
|
Processing Options:
STDEVTOL
Description
Any pixel column averages beyond this boundary will be excluded. The default value is
+- 1 standard deviation. Any pixel column average within this range will be included.
Normalization Options:
WIDTH_PIXELS
Description
If value is left at zero, pixels will be normalized using entire width frame of image.
Normalization Options:
HEIGHT_LINES
Description
If LINESCAN, height will always equal 1. If value is left at zero and is not LINESCAN,
pixels will be normalized using entire frame height of image.