ISIS Application Documentation
Stitch together multiple HiRISE CCD images
Description
This program combines images from multiple HiRISE CCDs into a single
output image file. The output file can be considered to be a special
type of mosaic in which the different CCD images are placed next to
each other in positions that correspond to detector numbers. The input
files must each contain both channels of a single detector, which are
the files produced by the "histitch" program. CCD images with lower
CCD numbers are placed into the output file to the left of CCD images
with higher CCD numbers. By default the CCD images are placed into the
output file from left to right, i.e., in order of increasing CCD number. This
order can be changed with the MosaicOrder keyword in the "shiftdef"
file.
Images are inserted at locations
corresponding to the relative offsets of the detectors. In most cases,
pixel replication is used when processing an input image so that it
matches the scale of the image with the lowest summing mode. However,
if any of the input images were observed with a summing mode of 3, then
pixel replication is used for all images to match the scale that would
have been obtained with a summing mode of 1. No resampling of input
pixel values is done.
In many cases, adjacent images do not line up vertically due to observing
conditions and other factors. The SHIFTDEF parameter allows the user to
apply arbitrary offsets in lines to any or all the input images so they align
properly.
It has been determined that summing modes add an additional delay to
imaging due to pre-cycling of the detector electronics. Typically, images
have an additional 180 * (summing mode - 1) lines delay
in the actual imaging
of the target. These lines are unbinned, not subject to the summing mode
applied during imaging. This is not an issue if all images being stitched by
this application are the same summing mode. If images with different
summing modes are acquired in the same observation, then this offset
is automatically applied to the images with differing summing modes. This
will result in adding
lines of offset to some images and increasing the number of lines in the
resulting output image.
The input files may contain multiple bands but all input files must contain
the same number of bands. This is useful for creating color products
where the input files are compatable with the constraints of this application.
Categories
History
Jim Torson | 2005-06-24 |
Original version
|
Kris Becker | 2006-03-02 |
Eliminated the requirement that all CCDs be adjacent. As a side
effect, 24 pixels on the left edge of the adjacent CCDs are no
longer clipped but are layed on top of the last 24 pixels on the
right side of preceding CCDs.
|
Kris Becker | 2006-03-31 |
Added the SHIFTDEF parameter that allows for offsets to be provided
for any CCD. Also added the PLACEMENT parameter that writes the
line and sample coordinate of each CCD in the output TO file.
|
Kris Becker | 2006-09-27 |
Added recently discovered time delay as a function of summing modes.
This adds lines of offset to images with higher summing modes. These
lines are unbinned but are subject to the smallest occuring summing
mode in that the offsets are reduced by the number of offsets divided by
the minimum summing mode.
|
Kris Becker | 2006-11-27 |
Modified to allow a single CCD image file as input to hiccdstitch.
Previously, two or more CCDs image files were required. With this
change only one need be provided (to expedite pipeline processing).
|
Tracie Sucharski | 2007-03-13 |
Modified to allow user to determine the order the ccd's are laid down
through the use of the MosaicOrder keyword in the shiftdef file.
Also added option to replicate pixels by nearestNeighbor, Bilinear
or cubicConvolution. Also deleted ChannelNumber and CpmmNumber
keywords so that output image cannot be projected.
|
Kris Becker | 2007-07-31 |
Modified to allow for stitching of multiband cubes. This will allow
users to create color products as long all files have the same
number of bands.
|
Steven Lambright | 2008-05-13 |
Removed references to CubeInfo
|
|
Parameter Groups
Input Files
Name
|
Description
|
FROMLIST |
List of cubes to stitch together
|
SHIFTDEF |
Pvl file containing mosaic order for ccd's and the absolute shifts for CCD
lines and samples.
|
Output Files
Name
|
Description
|
TO |
Output stitched cube
|
PLACEMENT |
Output file providing the placement of CCDs in the TO cube
|
Interpolation
Name
|
Description
|
INTERP | Type of interpolation |
|
Input Files:
SHIFTDEF
Description
This file contains objects for each CCD and for each combo
of binning/tdi that requires a
modification to its placement in the mapping of the HiRISE
focal plane. The name of each object is the CCD name for
which the shift in line or sample is needed. For example, the
leftmost CCD, CCD 0 is named "RED0", the next "RED1" and
so on. The binning/tdi groups are named by combining the
binning and tdi mode. For example, summing=1 and tdi=64 the
group would be "1/64". Hiccdstitch searches for names of objects that match
the stitched input cube files ccd then for the proper combo of summing and tdi.
If the group for summing/tdi isn't found, values from the ccd object will be
used. These offsets will be applied to the
default sample and line location of where the CCD is mapped to
in the focal plane.
Offsets for both line and sample can be supplied. None, one or
both can be provided for any CCD. Negative values shift the
image left if a sample offset is given or up if a line offset is given.
Positive values in sample and line shift the image right and down,
respectively.
These shifts are absolute shifts and only apply to
the specified CCD and are not propagated to subsequent CCDs
left to right in the focal plane layout. (HiRISE CCD arrangement
is always left to right as far as hiccdstitch is concerned, unless
overiridden by the MosaicOrder keyword.) For
example, if stitching all 10 RED CCDs in an image you find that
RED5 must be shifted left 20 pixels but all other CCDs line up file
to the right, meaning RED6 through RED9, then you are required
to privide groups for RED6, RED7, RED8 and RED9 with the same
SampleOffset provided for RED5. This is the only way proper
sample alignment is retained.
Below is an example of the format of the input file for the
SHIFTDEF file:
Object = Hiccdstitch
# Defaults for Red0 images
Object = RED0
SampleOffset = -10
LineOffset = 5
# Summing=1, Tdi=64 values. Any of the three keywords (MosaicOrder, SampleOffset, LineOffset)
# can exist in the summing/tdi groups that will override the defaults in the RED0 object.
Group = 1/64
SampleOffset = 0
LineOffset = 0
End_Group
# Summing=1, Tdi=128
Group = 1/128
SampleOffset = 20
End_Group
# If a summing/tdi group does not exist, the ccd defaults are used
End_Object
Object = RED3
SampleOffset = 13
LineOffset = -5
End_Object
Object = RED5
LineOffset = 22
End_Object
Object = RED9
# MosaicOrder of -1, indicates the ccd is placed in mosaic first.
MosaicOrder = -1
End_Object
Object = IR11
SampleOffset = -4
LineOffset = 2
End_Object
Object = BG12
SampleOffset = 12
End_Object
End_Object
End
The only keywords that hiccdstitch reads from this file
are SampleOffset , LineOffset and
MosaicOrder. All other keywords are ignored.
All CCD objects must be contained within the
Hiccdstitch object.
Note that this file is an optional parameter. If it is not
provided, then all CCD files provided are mapped to
focal plane positions as specified in the HiRISE
Instrument Operations Handbook. Note that the size
of a HiRISE pixel is 0.012 millimeters and the measurements
in the handbook are also in millimeters.
Type
| filename |
File Mode
| input |
Default Path
| $mro/calibration |
Default
| $mro/calibration/HiccdstitchOffsets.def |
Filter
|
*.def
|
Output Files:
TO
Description
The output cube into which the input cubes will be placed.
Type
| cube |
File Mode
| output |
Filter
|
*.cub
|
Output Files:
PLACEMENT
Description
If provided, the actual line and sample locations of each CCD as
they map to the TO cube are recorded here. This format is the
the same as the format provided in the STITCHDEF file.
Type
| filename |
File Mode
| output |
Internal Default
| None |
Filter
|
*.def
|
Interpolation:
INTERP
Description
This is the type of interpolation to be performed on the input when
ccds of different summing modes are combined.
Type
| string |
Default
|
NEARESTNEIGHBOR
|
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 Convolutioin interpolation |
Each output pixel will be set to the value calculated by
a cubic convolution interpolation of the calculated input pixel.
|
|