grid

This program superimposes a user-defined grid on an input image.

Two types of grids are available:

1. A graticule based on latitude and longitude coordinates where (MODE=GROUND).
2. A simple rectangular grid based on line and sample coordinates where (MODE=IMAGE).

Defaults:

• MODE = GROUND
• BASELAT = 0.0
• BASELON = 0.0
• LATINC = 10
• LONINC = 10

Use the GROUND mode for images that have SPICE or map projection information. Use the IMAGE mode for images that do not have SPICE or map projection information, or to draw grid lines based on sample and line information.

The grid pattern will intersect a specific origin of either (latitude,longitude) or (sample,line) position. Grid lines are drawn at intervals from the origin based on the increment values defined by the user. The graticule produced may not match the image coordinates exactly, so the result will have outer grid cells that might have different heights and widths than the interior grid cells. In addition, if the LATINC and LONINC are too large compared with your image map scale, the grid lines may miss your image. If the increments are too small, the grid lines may be overly dense.

This application will draw grids on either ISIS level0, level1 (with successful spiceinit), and level2 cubes, or mosaics. The mapping information in the labels will be used to draw grid lines on mosaics and Level2 images. If the latitude and longitude information cannot be calculated or extracted using the image label contents, then use the IMAGE mode.

For Cubes with an associated band-dependent camera model (latitude, longitude coordinates do not correspond to the same sample, line coordinates in each band,) the grid is recalculated for each band.

Example Parameter Settings for Grids:
Example 1: Superimpose a basic latitude/longitude graticule with grid lines drawn every 10 degrees based on zero:
MODE=GROUND BASELAT=0 BASELON=0 LATINC=10 LONINC=10

Example 2: Superimpose a graticule on an input image that intersects at line 23 and sample 17, with vertical lines drawn every 30 pixels and horizontal lines every 40 pixels:
MODE=IMAGE BASELINE=23 BASESAMPLE=17 SINC=30 LINC=40
Note: MODE=GROUND cannot be used when sample and line coordinates are used.

Example 3: Superimpose a latitude/longitude graticule with a grid intersection at -5.0 degree latitude and 140.0 degree longitude, with latitude lines drawn every 2.5 degrees and longitude lines drawn every 3 degrees:
MODE=GROUND BASELAT=-5.0 BASELON=140 LATINC=2.5 LONINC=3

Example 4: Superimpose a latitude/longitude graticule within a subarea of an image (full latitude and longitude extent), with a grid line drawn every 2.5 degrees between latitudes -8 and -1 degrees and only between longitudes 140 and 145 degrees:
MODE=GROUND BASELAT=0 BASELON=0 LATINC=2.5 LONINC=2.5 MINLAT=-8 MAXLAT=-1 MINLON=140 MAXLON=145 Bound=yes

For complex grids, the grid application can be run multiple times with different parameter settings for each successive run that builds onto the previous output file. The TICKS option can be used to draw short ticks instead of grid lines. The OUTLINE option will draw grid lines along the outside edges of the first and last samples and lines of the input file. The BOUNDARY option will either draw grid lines around the outside edges of the input file or around the bounding box specified by the user with MINLAT, MAXLAT, MINLON, and MAXLON parameters.

Description

Use this parameter to select the input file.

Type	cube
File Mode	input
Filter	*.cub

Description

This file will contain the gridded image.

Type	cube
File Mode	output
Filter	*.cub

Description

This allows for selection of either IMAGE or GROUND coordinates when drawing the grid.

Type	string
Default	GROUND
Option List:	Option Brief Description IMAGE Add a rectangular grid in terms of lines and samples A grid will be inserted into the image with spacing and position defined in line and sample coordinates. Exclusions BASELAT BASELON LATINC LONINC MINLAT MAXLAT MINLON MAXLON BOUNDARY GROUND Add a grid (graticule) in terms of lat/lon coordinates A grid will be inserted into the image with spacing and position defined in latitude and longitude coordinates. Exclusions LINC SINC BASELINE BASESAMPLE

Description

Draw ticks at grid line intersections (instead of drawing full lines).

Type	boolean
Default	false
Inclusions	DIAGONALTICKS TICKSIZE

Description

This will draw grid lines at the very edges of the image.

Type	boolean
Default	false

Description

This will draw grid lines (or ticks) at the lat/lon extents of the image or those extents as provided by user input MINLAT, MAXLAT, MINLON, and MAXLON.

Type	boolean
Default	false

Description

If false, the grid will stop at the longitude domain boundary, -180 to 180 or 0 to 360, if the minimum or maximum longitude values are outside of the domain range. If true, the grid will extend all the way to the minimum and maximum longitudes regardless of the domain.

Type	boolean
Default	false

Description

Starting line of grid. This, along with BASESAMPLE, defines the starting point (line) for drawing the grid.

Type	integer
Default	1
Minimum	1 (inclusive)

Description

Starting sample of grid. This, along with BASELINE, defines the starting point (sample) for drawing the grid.

Type	integer
Default	1
Minimum	1 (inclusive)

Description

This defines the line increment when drawing the grid, starting at BASELINE. The line increment is the spacing between lines.

Type	integer
Default	100
Minimum	1 (inclusive)

Description

This defines the sample increment when drawing the grid, starting at BASESAMPLE. The sample increment is the spacing between samples.

Type	integer
Default	100
Minimum	1 (inclusive)

Description

This is the latitude on which LATINC is mathematically based. This establishes a starting point for a global 'virtual' grid where latitude lines are drawn where the input image intersects the virtual grid. The application assumes user input reflects proper units (e.g. planetographic, planetocentric latitude) as defined within the image.

Type	double
Default	0.0
Minimum	-90.0 (inclusive)

Description

This is the longitude on which LONINC is mathematically based. This establishes a starting point for a global 'virtual' grid where longitude lines are drawn where the input image intersects the virtual grid.

Type	double
Default	0.0
Minimum	-360.0 (inclusive)

Description

This defines the latitude increment, based on BASELAT, on which grid lines are drawn. This establishes a global 'virtual' grid where latitude lines are drawn only where the input image intersects the virtual grid.

Type	double
Default	10.0
Minimum	0.0 (inclusive)

Description

This defines the longitude increment, based on BASELON, on which grid lines are drawn. This establishes a global 'virtual' grid where longitude lines are drawn only where the input image intersects the virtual grid.

Type	double
Default	10.0
Minimum	0.0 (inclusive)

Description

This defines the minimum latitude to which longitude grid lines will extend. If BOUNDARY is selected, a latitude line will be drawn at this latitude.

Type	double
Internal Default	Automatic
Minimum	-90 (inclusive)
Maximum	90 (inclusive)

Description

This defines the maximum latitude to which longitude grid lines will extend. If BOUNDARY is selected, a latitude line will be drawn at this latitude.

Type	double
Internal Default	Automatic
Minimum	-90 (inclusive)
Maximum	90 (inclusive)
Greater Than	MINLAT

Description

This defines the minimum longitude to which latitude grid lines will extend. If BOUNDARY is selected, a longitude line will be drawn at this longitude.

Type	double
Internal Default	Automatic
Minimum	-360 (inclusive)
Maximum	360 (inclusive)

Description

This defines the maximum longitude to which latitude grid lines will extend. If BOUNDARY is selected, a longitude line will be drawn at this longitude.

Type	double
Internal Default	Automatic
Minimum	-360 (inclusive)
Maximum	360 (inclusive)
Greater Than	MINLON

Description

This defines the thickness of grid lines in pixels.

Type	integer
Default	1
Minimum	1 (inclusive)
Odd	This value must be an odd number

Description

With this option choose DN, LRS, HRS, or NULL to define how to assign the grid line value. Use DNVALUE parameter to assign a number if DN option is chosen.

Type	string
Default	HRS
Option List:	Option Brief Description HRS Use HRS DN value Use the special pixel value HRS (High Representation Saturation) as the grid line value. This may vary with bit type used. Exclusions DNVALUE LRS Use LRS DN value Use the special pixel value LRS (Low Representation Saturation) as the grid line value. This may vary with bit type used. Exclusions DNVALUE NULL Use NULL DN value Use the special pixel value NULL as the grid line value. This may vary with bit type used. Exclusions DNVALUE DN Use given DN value Use the DN value specified in the DNVALUE parameter. It is recommended to run the stats application on the cube before selecting a DN value.

Description

This is the DN value to be used as the value of the grid lines when LINEVALUE=DN. It is beneficial to first run the stats application to determine image minimum and maximum values.

Type	double

Description

This option allows for any DN value, HRS, LRS, or NULL special pixel values to be chosen as the background value.

Type	string
Default	IMAGE
Option List:	Option Brief Description IMAGE Use the input cube value Use the input cube pixel value as the background value. This will superimpose the grid on top of the input image. Exclusions BKGNDDNVALUE HRS Use HRS DN value Use the special pixel value HRS (High Representation Saturation) as the background value. This may vary with bit type used. Exclusions BKGNDDNVALUE LRS Use LRS DN value Use the special pixel value LRS (Low Representation Saturation) as the background value. This may vary with bit type used. Exclusions BKGNDDNVALUE NULL Use NULL DN value Use the special pixel value NULL as the background value. This may vary with bit type used. Exclusions BKGNDDNVALUE DN Use given DN value Use the DN value specified in the BKGNDDNVALUE parameter. It is recommended to run the stats application on the cube before selecting a DN value. Inclusions BKGNDDNVALUE

Description

This is the DN value to be used as the value of the background when BKGNDVALUE=DN. It may be beneficial to first run the stats application to determine image minimum and maximum values.

Type	double

Description

Draw tick marks diagonally (creating an 'x'), instead of default vertical/horizontal ('+')

Type	boolean
Default	false

Description

This defines the width and height (which are always equal) of the tick marks in pixels.

Type	integer
Default	5
Minimum	1 (inclusive)
Odd	This value must be an odd number

In this example, the latitude and longitude grid lines are drawn every 10 degrees starting at 0.0 degree latitude and longitude.

grid from=aeolis_reduced.cub to=grid_ex1.cub

Grid GUI

Example GUI Screenshot of GUI with default parameters.

Input image

Input file Parameter Name: From This is the ungridded input image.

Gridded output image

Gridded output file Parameter Name: TO This file is gridded every 10 degrees in latitude and longitude starting at 0.0 degree latitude and longitude.

In this example, the grid lines are drawn based on the line and sample coordinates entered by the user in IMAGE mode.

grid from=aeolis_reduced.cub to=grid_ex2.cub mode=image baseline=23 basesamp=17 sinc=30 linc=40

Grid GUI

Example GUI Screenshot of GUI with parameter settings defined by the user.

Input image

Input file Parameter Name: From This is the ungridded input image.

Gridded output image

Output file Parameter Name: TO The grid lines intersect at line 23 and sample 17, with vertical lines drawn every 30 pixels and horizontal lines every 40 pixels outward from the origin.

In this example, the grid lines are drawn based on a set of user-defined values for the different latitude and longitude parameters. The graticule is drawn only within the minimum and maximum latitude and longitude extents entered by the user.

grid from=aeolis_reduced.cub to=grid_ex4.cub mode=ground baselat=0 baselon=0 latinc=2.5 loninc=2.5 minlat=-8 maxlat=-1 minlon=140 maxlon=145 bound=yes

Grid GUI

Example GUI Screenshot of GUI with parameter settings defined by the user.

Input image

Input file Parameter Name: From This is the ungridded input image.

Gridded output image using BOUND=YES

Output file Parameter Name: TO The grid lines intersect at 0.0 degree latitude and longitude, and increments every 2.5 degrees in latitude and longitude. The outer edges of the bounding box around the minimum and maximum extents are gridded (BOUND=YES).

Gridded output image using BOUND=NO

Second output file using BOUND=NO Parameter Name: TO The grid lines intersect at 0.0 degree latitude and longitude, and increments every 2.5 degrees in latitude and longitude. The outer edges of the bounding box are not gridded (BOUND=NO). Command line: grid from=aeolis_reduced.cub to=grid_ex4b.cub mode=ground baselat=0 baselon=0 latinc=2.5 loninc=2.5 minlat=-8 maxlat=-1 minlon=140 maxlon=145 bound=no