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USGS

ISIS 3 Application Documentation


histat

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Generates statistics about a HiRISE cube and ancillary data

Overview Parameters Example 1

Description

This program computes statistics about the HiRISE image and it's associated ancillary data including the calibration image, dark reference pixels, and buffer pixels. There are ten sets of statistics that will be produced using:
  • IMAGE_POSTRAMP
    • Lines postramp
    • The first 30 lines of image data
  • IMAGE
    • Remaining lines of image data after the postramp.
    • If the input image is 30 lines or less, then all statistics will be zero
  • IMAGE_DARK
    • Image dark reference pixels
    • 16 pixels per line
  • IMAGE_BUFFER
    • Image buffer pixels
    • 12 pixels per line
  • CAL_REVERSE
    • Calibration image reverse lines
    • First 20 lines of calibration image
  • CAL_MASK
    • Calibration masked lines
    • From 5 - 20 lines after reverse depending on TDI
  • CAL_RAMP
    • Calibration ramp
    • Remaining lines after masked lines
  • CAL_DARK
    • Calibration image dark reference pixels
    • 16 pixels per line
  • CAL_DARK_RAMP
  • CAL_BUFFER
    • The calibration image buffer pixels
    • 12 pixels per line
The following statistics for each data set will be produced:
  • Average
  • Standard deviation
  • Variance
  • Minimum
  • Maximum
  • Total pixels
  • Valid pixels
  • Null pixels
  • Low instrument saturation pixels
  • Low representation saturation pixels
  • High instrument saturation pixels
  • High representation saturation pixels
The statistics will be output to the print file and additionally, if the user specifies, a file using the TO parameter, the statistics will be written to the file in a standard PVL format which can then be read using the getkey program. Because the very edges of several parts of the image are often inaccurate, histat also has the ability to disregard some pixels. The first and last line of the calibration image is not regarded, nor are the first and last samples of any line in the calibration image. For this reason, an image with a calibration image of 62 lines by 512 samples will be broken down as follows:

Last 19 lines of the reverse readout pixels (all but the first)
All 6 (in this case) lines of the masked pixels
First 33 lines of the ramp pixels (all but the last)
Since the first and last samples of each of these lines is disregarded automatically, the user is left statistics for the three sections of a 60 line by 510 sample calbration image.

The user is given much more flexibility in excluding samples from the calibration and dark reference areas of the actual (not calibration) image. The specific parameters used are described in the "Parameters" section.


Categories


History

Jeff Anderson2004-06-18 Original version
Stuart Sides2005-07-06 Fixed reporting of special pixels within the HiRISE tables. Special pixels were not being converted from 16 bit signed word to 32 bit double values before being sent to the Statistics objects.
Drew Davidson2006-01-18 Added the ability to use offsets so that edges of the calibration data may be disregarded.
Drew Davidson2006-01-23 Seperated calibration image into reverse, masked, and ramp groups.
Drew Davidson2006-05-25 Changed the default offsets, keywords, and internal offsets, Also added the CAL_DARK_RAMP group and the IMAGE_POSTRAMP group
Stuart Sides2006-10-06 Fixed bug where the number of mask lines was calculated. This also effected the number of ramp lines.
Stuart Sides2006-10-06 Modified brief and full descriptions of the keywords for ignoring left and right edges of the different calibration and main image portions of the observation to eliminate identical descriptions.
Kris Becker2007-01-18 Merged the changes made by Drew Davidson with the USGS version to provide single source code management. Changed how the data is recorded. When a TO file is given output is not written to the terminal or the log file. If TO is not given, output is written to the terminal and the log file (default: print.prt).
Steven Lambright2008-05-13 Removed references to CubeInfo
Kris Becker2009-03-13 Corrected bug in computation of CAL_DARK_RAMP dataset. It was hardcoded for handling summing mode 1. It has been corrected to handle all summing/tdi combinations.
Christopher Austin2009-06-09 Removed tabs in source code, fixed the example, expanded and structured documentation.

Parameter Groups

Files

Name Description
FROM A HiRISE cube from the "hirise2isis" program.
TO Output file to contain statistics

use offsets

Name Description
USEOFFSETScrop the edge columns of regions

offsets

Name Description
LEFTIMAGEOffset for the left side of the image area
RIGHTIMAGEOffset for the right side of the image area
LEFTCALBUFFEROffset for the left side of the calibration buffer
RIGHTCALBUFFEROffset for the right side of the calibration buffer
LEFTCALDARKOffset for the left side of the calibration dark pixels
RIGHTCALDARKOffset for the right side of the calibration dark pixels
LEFTBUFFEROffset for the left side of the image buffer
RIGHTBUFFEROffset for the right side of the image buffer
LEFTDARKOffset for the left side of the image dark pixels
RIGHTDARKOffset for the right side of the image dark pixels
X

Files: FROM


Description

The file specification for the input HiRISE cube.

Type cube
File Mode input
Filter *.cub
Close Window
X

Files: TO


Description

This ascii file will contain the statistics of the various HiRISE components. It is written in such a format that the values can be read using the getkey program. This is useful for when developing scripts.

Type filename
File Mode output
Internal Default No Output file will be created
Filter *.txt
Close Window
X

use offsets: USEOFFSETS


Description

Boolean option to include offsets to disregard the edge columns (true) or to include all columns from all buffers (false).

Type boolean
Default TRUE
Inclusions
  • LEFTIMAGE
  • RIGHTIMAGE
  • LEFTCALBUFFER
  • RIGHTCALBUFFER
  • LEFTCALDARK
  • RIGHTCALDARK
  • LEFTDARK
  • RIGHTDARK
  • LEFTBUFFER
  • RIGHTBUFFER
Close Window
X

offsets: LEFTIMAGE


Description

this number of pixels will be ignored on the right side of the ramp, lines postramp, and image areas

Type integer
Default 0
Internal Default 0
Close Window
X

offsets: RIGHTIMAGE


Description

this number of pixels will be ignored on the right side of the ramp, lines postramp, and image areas

Type integer
Default 1
Internal Default 1
Close Window
X

offsets: LEFTCALBUFFER


Description

This number of pixels will be ignored on the left side of the buffer area of the calibration image

Type integer
Default 3
Internal Default 3
Close Window
X

offsets: RIGHTCALBUFFER


Description

This number of pixels will be ignored on the right side of the buffer area of the calibration image

Type integer
Default 1
Close Window
X

offsets: LEFTCALDARK


Description

This number of pixels will be ignored on the left side of the dark area of the calibration image

Type integer
Default 3
Close Window
X

offsets: RIGHTCALDARK


Description

This number of pixels will be ignored on the right side of the dark area of the calibration image

Type integer
Default 1
Close Window
X

offsets: LEFTBUFFER


Description

This number of pixels will be ignored on the left side of the buffer area of the main image

Type integer
Default 3
Close Window
X

offsets: RIGHTBUFFER


Description

This number of pixels will be ignored on the right side of the buffer area of the main image

Type integer
Default 1
Close Window
X

offsets: LEFTDARK


Description

This number of pixels will be ignored on the left side of the dark area of the main image

Type integer
Default 3
Close Window
X

offsets: RIGHTDARK


Description

This number of pixels will be ignored on the right side of the dark area of the main image

Type integer
Default 1
Close Window

Example 1

No offsets used

Description

Gathering statistics including all buffer and dark pixel values.

Command Line

histat from=histatExample.cub to=histatExampleStats.log useoffsets=false
In this example we disregard the ability to use offsets on the buffers. Since the default is to include offset values, we must explicitly set useoffsets to false.

GUI Screenshot

histat Gui

Example Gui

Screenshot of GUI with parameters set to gather stats without offsets.

Input Image

Input image

HiRISE input image for histat

Parameter Name: FROM

This is the input image for which we will gather statistics.

Data File

Links open in a new window.
Output from histats without offsets This is the output file from running histats without any offsets.