SYNOPSIS
rawtran [options] fileDESCRIPTION
Rawtran is an utility to convert of raw photos in .CR2, .CRW, MRW, NEF, RAF, etc. formats to the general astronomical FITS image format [4]. The identification of raw photo type and decoding itself is done via DCRAW utility by D.Coffin [2]. Dcraw needs to be available independently.Rawtran produces following kinds of FITS files:
- Type: color (-t 0)
- The output image is the color FITS image (as specified by Munipack [3]). It is intended for representation of color images.
- Type: instrumental (-t 1)
- The type provides absolutely raw access to data in FITS format. According to astronomical terminology, the single bands are in instrumental photometric system.
- Type: single spectral band (-t . -c .)
-
The type is intended for representation of the brightness in the selected color band.
All produced data are RELATIVE quantities only.
- Rawtran internally uses 4-byte (float) data representation for all operations.
OPTIONS
- -t [0|1]
- Specify a type of conversion. 0 for the standard spectral band(s) (default). 1 for Instrumental spectral band(s).
- -c [X|Y|Z|R|V|B|u|s] or [Ri,Gi,Gi1,Gi2,Bi]
- Select a color band. Wrong specification is silently ignored.
- -B [8|16|32|-32]
- Select bits per pixel of an output image. Possible values are: 8 (0-255), 16 (0-65535), 32 (0-4294967296) and -32 (-10^38 .. 10^38), (values in braces indicates numerical range). An optimal bitpix for raw (instrumental) data is 16 (default) which covers a full range of digital cameras. The representation occupies width*height*2 bytes. Some out of range (rare) values will suppressed (cut off). The representing by float numbers (eg. -32) is recommended value for images intended for further processing because saves numerical precision and their numerical range (but occupies of twice more space with respect to 16). 8 bits reduces range (eg. suppress dynamical range) and 32 wastes a lot of storage place only.
- -o filename
- Specify an output file name. If the option is not used, the output is stored as rawtran.fits. Use dash '-' for redirection to the standard output. Precede the filename with exclamation point(!) to overwrite existing file.
- -X options
- Specify additional options to dcraw itself. If you passed an option with parameter or more options, please, enclose ones to quotes or apostrophes. In doubts, use -X "-v" to show detailed description of conversion by dcraw.
- --help
- Show summary of options.
- --version
- Display software version.
RETURN VALUE
The zero indicates successful conversion. A non-zero value is returned when an error occurs during conversion. If the utility is launched without options or with -h switch, zero means that rawtran's internal checker can run dcraw binary and non-zero value otherwise.EXAMPLES
Convert an image to be equivalent to humans eye brightness sensitivity at day:- bash$ rawran IMG_0666.CR2 -o IMG_0666.fits
- Convert an image to be equivalent to Landolt's B filter:
-
- bash$ rawran -c B IMG_0666.CR2 -o IMG_0666.fits
- Produce a color FITS and show it in xmunipack:
-
$ rawran IMG_0666.CR2 -o IMG_0666.fits
$ xmunipack IMG_0666.fits
- Get green component of RAW:
- $ rawran -t 1 -c Gi IMG_0666.CR2 -o IMG_0666.fits
- Overwrite an output file:
- $ rawran IMG_0666.CR2 -o '!IMG_0666.fits'
- A large set of RAW images can be converted with help of shell:
-
- $ for A in *.CR2; do rawtran $A -o ${A%CR2}fits; done