This program uses a text-based list of cubes, all in the same map projection and equivalent projection parameters (PixelResolution,
CenterRingLongitude, etc), to generate a mosaic. By default,
The program automatically determines the size of the mosaic by examining each cube. The user also
has the option of entering their own rad/az range to use for the mosaic.
There are four different ways/priorities (input, mosaic, band, average)
for how the input image has to be placed on the mosaic.
Priority Input will place the input image on top of the mosaic.
Priority Mosaic will place the input image beneath the mosaic.
Priority Band will place the input image on the mosaic based on the "Lessser" or "Greater" criteria
between user defined band in the input and the mosaic images.
Priority Average will average the valid pixels in the input and mosaic images. For each mosaic band, a count band is maintained. The count band
keeps track of the number of images involved in the averaging of the dn value for each pixel in the mosaic. Choosing this priority will cause the mosaic to have twice the number of
bands of the input image, with a count band for each band. Hence the file size of the mosaic is doubled due to the count band.
In case of special pixels and the special pixel flags being enabled, the details
for each priority is described below.
Tracking can be set at the time of Mosaic creation
only and cannot be turned on after the mosaic is created. But the tracking
will be turned off for multiband ONTOP and BENEATH priority even though it
was turned on while creating the mosaic. Tracking for multiband input with
ONTOP priority is possible only if all the Special Pixel Flags are set to
True else the Tracking will be turned off. ONTOP priority basically places
all the valid input pixels onto the mosaic unless the special pixel flags
are turned on or if mosaic has a NULL pixel. In a multi band scenario, a
pixel origin in particular line and sample will not be the same in all the
different bands, which means we have to keep track of every pixel in every
band. i.e. the size of the tracking bands will be the same as the number
of bands in the mosaic.i.e the number of bands will be doubled.
WARNING: If Tracking is turned on in a mosaic, any subsequent
applications that modify "dn" values will corrupt
the Tracking band. It may be necessary to remove
the Tracking band from the mosaic and then add it
back after all the processing is complete. See
"crop" and "cubeit".
Priority BAND can track origin for multi band input image based on a
specified band using LESSER or GREATER than criteria. Each pixel in the
specified band is compared to the corresponding pixel in the chosen band
in the mosaic based on the chosen criteria. This comparison true or false
is used for all the other bands whether the input pixel is copied onto the
mosaic and hence the origin for that pixel is stored. Band can be chosen
by choosing the TYPE, BANDNUMBER or KEYWORD. If BANDNUMBER is chosen then
the band number can be entered in the NUMBER field. If KEYWORD is chosen
then PVL key name and value from the BANDBIN group can be entered in the
KEYNAME and KEYVALUE fields.
For example, for a multi band input with BAND priority, if the BAND
chosen is Emission Angle band(EMA), if input pixels are (30,30,30) in
EMA Band for some sample, line and the corresponding pixels in the EMA
band in the mosaic has (75, 75, 75) and the criteria is GREATER than,
then since input pixels are not GREATER than corresponding mosaic
pixels, then the input pixels are not copied to the mosaic, so also the
corresponding pixels in all the other bands in the input. Hence the
origin for those pixels remains unchanged. If LESSER than was the
criteria, then all the corresponding pixels in all the input bands will
be copied to the mosaic and the origin for those pixels is the current
input image.
There are options like MATCHBANDIN, if set requires the specfied input
bands to match the mosaic bands and the bands can be anywhere in the
mosaic but must be contiguous for multi-band. If MATCHBANDIN is not set
then any input image can be placed on the mosaic within it's boundaries.
Options HIGHSATURATION, LOWSATURATION and NULL if
set will cause the the input pixels with these values to be copied to the
mosaic for ONTOP and BAND priorities regardless of the CRITERIA for the
BAND priority. These options are not supported for BENEATH priority.
Currently Tracking can be viewed in the Advanced Tool Tracking option
of the qview application. Following are the Tracking info:
Index : Zero based and is in the order in which the image was
placed on the mosaic. No origin is represented as -1.
FileName: File name of input image
Serial Number:Serial Number of the input image
Following are the values for the origin band depending on the pixel type
Pixel Type
(bits) | Default
(No Origin) | Start Value | Max Value | Total Images
Supported |
| 32 | -16777216 | -16777215 | 16777216 | 33549932 |
| 16 | -32768 | -32767 | 32767 | 65535 |
| 8 | 0 | 1 | 255 | 255 |
Following is the table for Special Pixel options, input, mosaic
pixels and the resulting output for different priorities.
Tags: F(FALSE), T(TRUE), V(VALID), HS(HIGH SATURATION), LS(LOW SATURATION),
S(SPECIAL PIXEL HS, LS, NULL), N(NULL), I(INPUT), M(MOSAIC), HL(HS,LS)
| Priority Beneath |
|
 | |
| BENEATH |
| Input | Mosaic | Output |
| S,V | N | I |
| S,V | HL,V | M |
|
| Priority OnTop |
|
 | |
| ONTOP |
| Options | Images |
| HS | LS | NULL | Input | Mosaic | Output |
| F | F | F | V | S,V | I |
| F | F | F | S | HL,V | M |
| F | F | F | S,V | N | I |
| T OR | T OR | T | V | S,V | I |
| T OR | T OR | T | S | S,V | I (H,L,N) |
|
| Priority Band |
|
 | |
| BAND |
| Options | Images |
| HS | LS | NULL | Input | Mosaic | Output |
| F | F | F | V | V | Criteria based |
| F | F | F | V | S | I |
| F | F | F | S | HL,V | M |
| F | F | F | S,V | N | I |
| T OR | T OR | T | S | S,V | I(H,L,N) |
| T OR | T OR | T | V | V | Criteria based |
| T OR | T OR | T | V | S | I |
|
| Priority Average |
|
| |
| AVERAGE |
| Options | Images |
| HS | LS | NULL | Input | Mosaic | Output | Count |
| F | F | F | V | V | Average | count++ |
| F | F | F | V | S | I | 1 |
| F | F | F | S | S | M | 0 |
| F | F | F | S | V | M | count |
| T OR | T OR | T | S | S,V | I | 0 |
| T OR | T OR | T | V | V | Average | count++ |
| T OR | T OR | T | V | S | I | 1 |
|
