# coyote: CGRESIZERASTER

- coyote/Graphics
- [Source code]

Description

      The purpose of this program is to resize a raster file according to
      instructions from the user. It was designed specifically to resize the
      extremely large raster files created by IDL's function graphics commands
      from within an IDL program. It requires ImageMagick be installed and able
      to be called from a SPAWN command from within IDL.

Categories

      Graphics

Params

      rasterfile: in, required, type=string
           Set this parameter to the name of the raster file to be resized. The resized
           file will have this same name unless the `KEEP_ORIGINAL` keyword is set, in
           which case an "_rs" will be appended to the base name given by this parameter.
      percentage: in, optional, type=float
           A resize percentage. A value of 50, for example, will make the output file
           half its original size. A file may be made bigger by specifying a percentage
           greater than 100 (e.g. 150). The default is to calculate a precentage that makes
           the longest dimension of the output file approximately 600 pixels.

Keywords

      keep_original: in, optional, type=boolean
           Set this keyword to keep the original file. Otherwise, the file is overwritten with
           the resized file. If this keyword is set, the output file will use the same name as
           the input file, except an "_rs" will be appended to the base name of the input file.
      height: in, optional, type=integer
           Set this keyword to set the height of the resulting raster file in pixel units. The width of the
           raster will be such as to preserve the aspect ratio of the starting image. This keyword
           cannot be used if the `WIDTH` keyword is used at the same time.
      silent: in, optional, type=boolean, default=0
           Set this keyword to suppress printed output from the program.
      width: in, optional, type=integer
           Set this keyword to set the resulting width of the raster file. The height of the
           raster will be such as to preserve the aspect ratio of the starting image. This keyword
           cannot be used if the `HEIGHT` keyword is used at the same time.

Examples

      Here is how to use this program::
         IDL> cgResizeRaster, 'picture.png', /Keep_Original, Width=500

Author

      FANNING SOFTWARE CONSULTING::
         David W. Fanning
         1645 Sheely Drive
         Fort Collins, CO 80526 USA
         Phone: 970-221-0438
         E-mail: david@idlcoyote.com
         Coyote's Guide to IDL Programming: http://www.idlcoyote.com

History

      Change History::
         Written, 15 January 2014 by David W. Fanning.

Copyright

      Copyright (c) 2014, Fanning Software Consulting, Inc.