From: "Ara.T.Howard" <Ara.T.Howard@...>
Date: 2004-05-19T09:33:48+09:00
Subject: RMagick jp2 problem


the following program:

  ~ > cat tiff2jp2 
  require 'RMagick'
  tiff = ARGV.shift
  jp2 = ARGV.shift || tiff.gsub(%r/tiff?/o,'jp2')
  img = Magick::Image.read(tiff).first
  img.write jp2


results in quite a 'lossy' transformation even though the docs caim a default
compression type of lossless jp2.  i've played with both quality and
compression settings and always lose data with this method

however, using this  command:

  tifftopnm image.tiff | jasper --input-format pnm --output-format jp2 > image.jp2

does NOT lose data so this shows that that jasper jp2 lib IS capable of doing
lossless compresion

any ideas on why this is?

-a
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