ISIS Application Documentation
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Create a flat-field image for line-scan, push-frame, and framing instruments
Description
Categories
Groups
History
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
- Push Frame
- Framing
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)))
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)))
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
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: |
|
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.
| Type | integer |
|---|
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.
| Type | integer |
|---|
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: |
|
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.
| Type | double |
|---|---|
| Default | 2 |
Normalization Options: WIDTH_PIXELS
Description
If value is left at zero, pixels will be normalized using entire width frame of image.
| Type | integer |
|---|---|
| Default | 0 |
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.
| Type | integer |
|---|---|
| Default | 0 |
History
| Victor Silva | 2016-09-12 | Original version, Adapted from Isis version of makeflat. |