NAME

mkshift -- generate a script file to shift many images to a reference image

USAGE

mkshift coord_file script_file

PARAMETERS

coord_file

the name of a text file containing (x y imagename) sequences, possible generated by ICNTR.

script_file

the name of a text file to hold the CL script which will shift the images having coordinates in the "coord_file"

DESCRIPTION

Given a list of images and positional references (stars) in each image, a mean shift is determined for each image which will place it positionally to be congruent with the first image.

It is assumed that for each image in the coordinate file, there are the same number of coordinates, and that the coordinates occur in the same order for each image. It isn't necessary for the coordinates to be all for the first image, and then all for the second, and so on. For example, the following file is valid:

12.2 30.3 image1
13.1 31.1 image2
14.1 32.1 image3
123.4 100.5 image1
201.1 202.2 image1
124.5 100.1 image2
200.2 204.1 image2
122.2 99.8 image3
201.2 205.1 image3

The average shifts are computed and then implanted in a command script to the IMAGES task, IMSHIFT. Script commands for HEDIT are also generated so that the image headers are updated with the shift value using keywords XSHIFT and YSHIFT.

The script may be executed by typing

cl> cl <script_file

The script forces all the shifted images names to take on the suffix "s".

EXAMPLES

Assume a coordinate file named "coords" has been generated somehow. The following commands will generate a script named "shifty", and then execute the script.

cl> mkshift coords shifty
cl> cl <shifty

TIME REQUIREMENTS

Fast

SEE ALSO

IMSHIFT, ICNTR