Module: RFits::Compressible

Module

RFits::Compressible

In:

lib/rfits/rfits.rb

A set of routines for setting and retrieving compression characterstics.

Methods

activate_compression compression_type compression_type= deactivate_compression hcomp_scale hcomp_scale= hcomp_smooth hcomp_smooth= noise_bits noise_bits= tile_dim tile_dim=

Constants

 {       IO::Proxy::RICE_1 => :rice,       IO::Proxy::GZIP_1 => :gzip,       IO::Proxy::PLIO_1 => :plio,       IO::Proxy::HCOMPRESS_1 => :hcompress
 'ZNAXIS'
 'ZCOMPTYPE'
 'ZTILE'
 'ZNAME'
 'ZVAL'
 'NOISEBIT'
 'SCALE'
 'SMOOTH'

Public Instance methods

activate_compression()

Activate compression on the image. "options" is a hash with the following keys:

:compression_type: the type of compression (:rice, :gzip, :plio, :hcompress). Required.
:tile_dim: the size of the tiles used in compression. Optional.
:noise_bits: applicable for floating point images only. Optional.
:hcomp_scale: scale factor for use in hcompress compression. Optional.
:hcomp_smooth: smoothing factor for use in hcompress compression. Optional.

compression_type()

Retrieve the compression type of the image. Possible values: :rice, :gzip, :plio, :hcompress

compression_type=(ctype)

Set the compression type of the image. Possible values: :rice, :gzip, :plio, :hcompress

 image.compression_type = :gzip

deactivate_compression()

Turn off compression for the image.

Get the hcompress scale if the image is compressed using hcompress.

hcomp_scale=(scale)

Set the hcompress scale if the image is compressed using hcompress.

Get the hcompress smoothing factor if the image is compressed using hcompress.

hcomp_smooth=(smooth)

Set the hcompress smoothing factor if the image is compressed using hcompress.

Get the noise bits for the compressed image.

noise_bits=(bits)

Set the noise bits for the compressed image.

Get the tile dimensions for the compressed image.

tile_dim=(tilesizes)

Set the tile dimensions for the compressed image.

 image.tile_dim = [5, 5]