newextraction image template
image
Image to be extracted.
template
The previously created database for the template image is used to initialize
the new database. If the null string is given then the database is not
initialized.
sample_lines = 10x50
Sample image lines in which the spectra positions are to be determined and,
optionally, modeled. This parameter is not used if a template image is given.
To extract the spectra from a multi-spectra image a database must be created and associated with the image. This task creates the database with a name formed by adding the extension '.db' and initializes some of the database entries.
The sample lines are used to track the spectra positions and, if an analytic profile model is to be fit to the spectra, to map profile shape changes. The image lines only need be sampled enough to track non-linear position distortions and significant profile shape changes since interpolation is used between the sample lines. Though specifying just one sample line is allowed using at least two sample lines is recommended to allow for any slope in the position of the spectra. Specifying all the image lines will greatly increase the processing time and is never justified.
Using a previous database to initialize the new database is useful if the new image is only slightly different in the positions and profiles of the spectra. In some cases extraction may proceed immediately without any further position determination and modeling. Further modeling and spectra position determinations will refine the previously determined parameters with an increase in execution time. Using a template image is particularly important if the first image extracted has strong spectra and subsequent images have much weaker spectra since the automatic spectra position location and profile modeling may yield poor results for very weak spectra.
To initialize a MULTISPEC database for extracting the spectra in the image image1:
cl> newextraction image1 ""
To create a new MULTISPEC database for extracting the spectra in the image image2 using image1 as a template image:
cl> newextraction image2 image1