Input can either be a single 3-D file, containing at least 3 channels, or it may be a set of at least 3 files, each holding one channel. If a single file is input, the user may specify which channels are to be used in the destretch, by means of the BANDS parameter.
OUT contains the names of theoutput datasets that contain the transformed images. Output can either be a single 3-D file, containing at least 3 channels, or it may be a set of at least 3 files, each holding one channel.
The standard Vicar size field ( starting_line, starting_sample, number_of_lines, number_of_samples).
Starting line of the portion of the image that you wish to process.
Starting sample of the portion of the image that you wish to process.
Number of lines in the portion of the image that you wish to process.
Number of samples in the portion of the image that you wish to process.
If the value of the parameter MATRIX is "CORR" (the default), the image's correlation matrix is used to determine the decorrelation stretch transformation. If the value of MATRIX is "COV", then the covariance matrix is used instead.
Statistics are gathered using only every n'th line and n'th sample of the image, or region of interest (AREA) within the image. The parameter INC specifies the value on "n".
If there are multiple input files, this parameter is ignored. If there is a single multichannel input file, this parameter specifies which of the bands to use. If defaulted all channels are used (up to 32). If specified, the user must list at least 3 bands, but no more than 32.
The value of the QA parameter indicates the presence and location of an
ASTER defined QA plane. A value of 0 (the default) indicates that no QA
plane is being provided. If the value is non-zero, then the value indicates
the channel number of the QA plane, if there is a single file input, or that
the last input file is the QA plane, if there are multiple input files.
The meanings of QA pixels are as follows:
Pixels with a value greater than 15 are excluded from statistics
gathering.
Pixels with a value of 144 are replaced in the output image with
a value of 0 in all channels.
Under normal operation, each of the eigenvectors (and, hence, each of the principal components) is given equal weight. If the DSCALE parameter is used, each successive eigenvector is weighted by the corresponding DSCALE value. This can be used to suppress components known to be noisy, at the expense of re-introducing some correlation among bands. The default is equivalent to all DSCALE values being 1.0. When DSCALE is used, the typical usage is for the series of values go from large to small.
Sets of (Starting_line, Starting_sample, Number_of_lines, Number_of_samples) are given to define subareas used to generate the image statistics. Up to 50 set of subareas may be supplied. The default is that the entire image is sampled.
A rescaling factor is included in the overall transformation to reposition the output values in a range appropriate for byte data output. The MEAN parameter specifies the desired mean value for the output image channels. If the AREA parameter has been used, this target mean is for the AREA(s) of interest only.
A rescaling factor is included in the overall transformation to reposition the output values in a range appropriate for byte data output. The SIGMA parameter specifies the desired standard deviation from the mean value in each of the output image channels. If the AREA parameter has been used, this target standard deviation is for the AREA(s) of interest only.
If the EXCLUDE parameter is given, any pixel that has a zero value in all input bands will be excluded from the statistics. If the EXCLUDE parameter is not given, the pixels are included.
If the SAVE parameter is given a value, the destretch transformation matrix will be saved as a VICAR parameter dataset, and have the dataset name specified by the save parameter. This parameter dataset may then be included in the parameters for XFORM, to repeat this transformation on other datasets.