backgroundimage: Construct an image of background radiation
The "backgroundimage" program can
calculate images of non-diffraction background.
Usage
The program is invoked by the command line:
backgroundimage [options] <imagefilenames> [write=imagefilename]
Different image file types are
recognized from their names.
The outputfile produced by the program contains the data for the n-th
(default value for n=3) lowest value obtained for each pixel, preceded
by the header of the last file that was read. The output file always
consists of a single frame without repeats.
Options
The program accepts the options to determine KCD file scaling. The default output
file name is background.kcd
Other options are:
- n=#
-
Change the value of N. Please note that increasing N significantly
increases memory usage and run time of the program. The option N must
be given before any filenames on the command line, otherwise the
output file will be meaningless.
Specifying "n=1" is equivalent to using the "min"imum option of the imagesum program, but a bit less efficient.
- rescale
-
Forces a re-scaling of the output image such that the lowest pixel
value is 0 and the highest pixel value is 65535. Without this option,
images will only be rescaled if the total range of values in the image
is larger than 65536.
- clip
-
Tells the program to clip values that are above 65536 and below 0, and
not touch the scaling. clip is equivalent to specifying shift=0
scale=1.0
-
- scale=## and shift=##
-
For more control over scaling, the
option "scale=##" can be used to scale the image by a fixed amount
instead of determining the best scale factor automatically. The option
"shift=##" can be used to prevent clippage of negative values by
adding an offset to each pixel. By default, the shift is determined
such that no values will be clipped.
- write=xxx
-
Tells the program that the filename ("xxx") following it is the file
to write the result. Default: write=background.kcd
Examples
backgroundimage i01*.kcd
Writes the level-3 background radiation for the images to background.kcd
backgroundimage n=2 i01*.kcd to bg2.kcd
Writes the level-2 background radiation for the images to bg2.kcd
backgroundimage n=3 s01f??[05].kcd to bg.kcd
Makes a level-3 background radiation image for a long scan, using only
every fifth image.
See also
See also the makelow program for a front end
to backgroundimage
