cam2map

This program converts a cube in camera coordinates to a map projection. The input cube requires SPICE data and therefore the program "spiceinit" should be run on it prior to "cam2map". The map projection is defined using a PVL file specificied through the MAP parameter. The system default is to use the Sinusoidal projection ($ISIS3DATA/base/templates/maps/sinusoidal.map).

If you need to generate your own map file you can use the "maptemplate" program or alternatively, hand create a file using your favorite editor. The map file need only specify the ProjectionName as defaults will be computed for the remaining map file parameters. The following table indicates how the defaults are established:

PARAMETER	DEFAULT
TargetName	Read from Instrument group in the input cube labels
EquatorialRadius PolarRadius	Read from SPICE pck file set during spiceinit. The pck file is defined in the Kernels group via the TargetAttitudeShape keyword
LatitudeType	Planetocentric
LongitudeDirection	PositiveEast
LongitudeDomain	Normally, 360. However, if the cube crosses the longitude boundary the value will change to 180
MinimumLatitude MaximumLatitude MinimumLongitude MaximumLongitude	Computed from the input cube or read from the map file. However, any combination of the four values can then be overridden by the user
PixelResolution Scale	Computed from the input cube or read from the map file. The value can be overridden by the user.

If you only entered the input cube (FROM) and output cube (TO) and changed no other parameters the following is the default Mapping group:

  Group = Mapping
    TargetName             = Obtained from the Instrument group
    EquatorialRadius       = Obtained from TargetAttitudeShape kernel
    PolarRadius            = Obtained from TargetAttitudeShape kernel

    LatitudeType           = Planetocentric
    LongitudeDirection     = PositiveEast
    LongitudeDomain        = 360 (Could be automatically adjusted to 180 by LONSEAM)

    MinimumLatitude        = Computed from the input camera cube
    MaximumLatitude        = Computed from the input camera cube
    MinimumLongitude       = Computed from the input camera cube
    MaximumLongitude       = Computed from the input camera cube

    ProjectionName         = Sinusodial
    CenterLongitude        = Average of MinimumLongitude and MaximumLongitude
    PixelResolution        = Computed from the input camera cube
  EndGroup
    

Note that an important concept here is the map file can come from an existing map projected cube. Because the cube has PVL labels and contains the Mapping group, you can essentially force the input camera cube to have the same mapping parameters and/or selectively use some of the components of the cube's mapping group.

If you are attempting to construct a mosaic, it is important that the PixelResolution, EquatorialRadius, PolarRadius, LatitudeType, LongitudeDirection, LongitudeDomain, ProjectionName, and projection specific parameters (e.g., CenterLongitude, CenterLatitude) are the same for all cubes. That is, you should create one map file and use it as input for all the cubes in your mosaic. However, the ground range (MinimumLatitude, MaximumLatitude, MinimumLongitude, MaximumLongitude) should not be entered or you will create projected images with large amounts of NULL pixels. The following Mapping group could be used for mosaicking:

 Group = Mapping
   ProjectionName         = Sinusodial
   CenterLongitude        = 0
   PixelResolution        = 100 <meters>
 EndGroup
   

Finally, depending on the projection, problems can occur with cubes that fall on the projection longitude seam. For example, if you are making a mosaic with LongitudeDomain = 360 and your cube crosses 0/360 seam, this program would compute the default longitude range of the cube to MinimumLongitude = 0 and MaximumLongitude = 360. A very large output image could be created depending on the pixel resolution. The LONSEAM parameter allows you to selectively handle this case. If you are making mosaics near the seam you will need to understand and alter the default for this parameter.

Description

The specification of the input cube to be projected. The cube must have been initialized using the "spiceinit" program.

Type	cube
File Mode	input
Filter	*.cub

Description

A file containing the desired output mapping parameters in PVL form. This file can be a simple hand produced label file. It can also be an existing cube label which contains a Mapping group. You can produce map file using the "maptemplate" program.

Type	filename
File Mode	input
Default Path	$base/templates/maps
Default	$base/templates/maps/sinusoidal.map
Filter	*.map *.cub

Description

This file will contain the map projected image.

Type	cube
File Mode	output
Filter	*.cub

Description

This makes the number of lines, number of samples, resolution and ground range of the output cube match the MAP file.

Type	boolean
Default	false
Exclusions	PIXRES RESOLUTION DEFAULTRANGE MINLAT MAXLAT MINLON MAXLON

Description

This parameter is used to specify how the pixel resolution is obtained for the output map projected cube.

Type	string
Default	CAMERA
Option List:	Option Brief Description CAMERA Compute resolution from input cube This option will automatically determine the resolution from the input cube specified using the FROM parameter. Exclusions RESOLUTION MAP Read resolution from input map file This option will use either the PixelResolution (meters/pixel) or Scale (pixels/degree) in the map file. Exclusions RESOLUTION MPP Get resolution from user in meters per pixel This option allows the user to specify the resolution in meters per pixel using the RESOLUTION parameter Inclusions RESOLUTION PPD Get resolution from user in pixels per degree This option allows the user to specify the resolution in pixels per degree using the RESOLUTION parameter Inclusions RESOLUTION

Description

Specifies the resolution in either meters per pixel or pixels per degree

Type	double
Minimum	0.0 (exclusive)

Description

This parameter is used to specify how the default latitude/longitude ground range for the output map projected image is obtained. The ground range can be obtained from the camera or map file. Note the user can overide the default using the MINLAT, MAXLAT, MINLON, MAXLON parameters. The purpose of the ground range is to define the coverage of the map projected image. Essentially, the ground range and pixel resolution are used to compute the size (samples and line) of the output image.

Type	string
Default	MINIMIZE
Option List:	Option Brief Description MINIMIZE Minimize output image size This option will use the camera and projection in combination to ensure the output image size (samples, lines) is minimized. Using a ground range can cause NULL padding for projections with curved merdians and/or parallels and hence large output images. The amount of padding can be quite large for extremely high resolution maps. Exclusions MINLAT MAXLAT MINLON MAXLON TRIM Inclusions LONSEAM CAMERA Compute default range from input cube This option will automatically determine the mininum/maximum latitude/longitude from the input camera model cube specified using the FROM parameter. Inclusions LONSEAM MAP Read default range from map file This option will read the mininum/maximum latitude/longitude from the input map file. All four values are expected to be defined. Exclusions LONSEAM

Description

The minimum latitude of the ground range. If this is entered by the user it will override the default camera or map value. By default, planetocentric latitudes are assumed unless the MAP file specifies otherwise.

Type	double
Internal Default	Use default range
Minimum	-90.0 (inclusive)
Maximum	90.0 (inclusive)

Description

The maximum latitude of the ground range. If this is entered by the user it will override the default camera or map value. By default, planetocentric latitudes are assumed unless the MAP file specifies otherwise.

Type	double
Internal Default	Use default range
Minimum	-90.0 (inclusive)
Maximum	90.0 (inclusive)
Greater Than	MINLAT

Description

The minimum longitude of the ground range. If this is entered by the user it will override the default camera or map value. By default, positive east longitudes in the range of 0 to 360 are assumed unless the MAP file specifies otherwise.

Type	double
Internal Default	Use default range

Description

The maximum longitude of the ground range. If this is entered by the user it will override the default camera or map value. By default, positive east longitudes in the range of 0 to 360 are assumed unless the MAP file specifies otherwise.

Type	double
Internal Default	Use default range
Greater Than	MINLON

Description

If this option is selected, pixels outside the latitude/longtiude range will be trimmed or set to null. This is useful for certain projections whose lines of latitude and longitude are not parallel to image lines and sample columns.

Type	boolean
Default	FALSE

Description

With this option you can turn on/off the automatic longitude domain switching that occurs when a file crosses the boundary of the longitude domain (0-360 or -180 to 180). If the switching is turn off then you have the choice of making the program continue or exit when the cube does cross the bounday.

Type	string
Default	AUTO
Option List:	Option Brief Description AUTO Automatically correct Longitude Domain If the cube crosses the longitude seam automatically compute the LongitudeDomain When the cube is near 0 or 360 degrees the program will assume 180 LongitudeDomain. When the cube is near 180 or -180 degrees it will assume 360 LongitudeDomain. ERROR Abort program if cube crosses seam If the cube crosses the longitude seam the program will exit with an error message CONTINUE Continue program if cube crosses seam If the cube crosses the longitude seam the program will continue. The LongitudeDomain in the MAP file will be used. If the MAP file does not have a LongitudeDomain, 0-360 will be used. Note that this could create an extremely large image.

Description

This is the type of interpolation to be performed on the input.

Type	string
Default	CUBICCONVOLUTION
Option List:	Option Brief Description NEARESTNEIGHBOR Nearest Neighbor Each output pixel will be set to the pixel nearest the calculated input pixel. BILINEAR Bi-Linear interpolation Each output pixel will be set to the value calculated by a bi-linear interpolation of the calculated input pixel. CUBICCONVOLUTION Cubic Convolution interpolation Each output pixel will be set to the value calculated by a cubic convolution interpolation of the calculated input pixel.