The output image generated by vmos2band will be (r-2*bs) rows by (c-2*bs) columns with n bands, where r and c are the number of rows and columns per subimage, bs is the subimage border size, and n is the number of subimages that are to be put into band format. Vmos2band assumes that all subimages are same size (r*c) and all subimages have the same border size (bs). Subimages from the input mosaic image are assigned to bands in the multiband output image in the following manner: The first subimage specified is assigned to the first band in the output image. Subsequent bands are assigned subsequent subimages indexed from left to right, top to bottom. Vmos2band accepts VIFF data_types (excluding VFF_TYP_BIT) and returns that same data_type. If a map is associated with the input mosaic image, the same map will be assigned to the output multiband image.
Vmos2band does not work on explicit location data and will return an error when such an image is encountered. No output image will be created.
number of columns and number of rows in subimages
The -r and -c options are used to specify the number of rows and the
number of columns, respectively, per subimage. Vmos2band assumes that
all subimages in the mosaic image are the same size. The -r and -c
values SHOULD include any borders associated with the subimages.
The default subimage row and column sizes are 16 pixels.
subimage border size
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The -bs option allows the user to specify the subimage border size
in pixels. Again, this parameter will be applied to all subimages
in the mosaic. When vmos2band converts the mosaic image to a multiband
image, the subimage borders will be removed from the subimages before
storing them in bands. The size of the output image will therefore
be (r-2*bs) rows by (c-2*bs) columns by n bands.
The default subimage border size is 0 pixels.
overall mosaic image border size
The -bm option allows the user to specify, in pixels, the size of
an outer border that should be removed from the mosaic image before
extracting the subimages. The overall mosaic image border
and the subimage borders are independent.
The default overall mosaic image border size is 0 pixels.
horizontal and vertical offset of first subimage to be banded
The user can specify the first subimage in the mosaic that will be put into
the multiband output image by using the -x (horizontal offset) and -y
(vertical offset) options. The specified subimage will then be the
first band in the output image. The indices, x and y, index through the
subimages (they are NOT indices through the input mosaic image rows
and columns). Therefore, if a mosaic image contained
9 4-row by 4-col subimages arranged as 3 subimages in the horizontal
direction by 3 subimages in the vertical direction, the center
subimage would be indexed by x=1, y=1 (not by x=4, y=4).
The default first subimage is the first subimage in the mosaic (x=0, y=0).
number of subimages to be put into band format
The user can also specify how many images will be put into band format,
starting with the first subimage (described above),
by specifying the -n option. If the specified number of subimages
cannot be extracted, vmos2band will return an error and the output
image will not be created. If the -n option is not specified, vmos2band
calculates the number of subimages that will be banded, taking into account
both the subimage skip value and the first subimage offsets.
subimage skip value
The subimage skip value option (-s) allows the user to specify that
the next s subimages be skipped each time a subimage is stored as a
band. For example, a skip value of s=1 in a 3x3 subimage mosaic would
band the subimages in a checkerboard pattern (every other subimage is
a band in the output image).
When applying the subimage skip value, vmos2band looks at the series of
subimages as a linear array. Therefore, the row/column arrangement of
subimages does not affect how the skipping occurs.
vmos2band -i mosaic.xv -o band.xv -r 18 -c 18 -bs 1 -n 3
Will return a 3 band image of dimension 16 rows by 16 cols. Since there is a border of 1 (-bs 1) around the image, the resulting image is 16 rows by 16 cols.
Vmos2band does not work on explicit location data and will return an error when such an image is encountered. No output image will be created.