From: Chris Pine <glyconis@...>
Date: 2005-04-13T01:46:54+09:00
Subject: Re: RMagick question

What we do is shrink it down to fit in the thumbnail size, and fill in
the rest with white.  No cropping, but you get a lot of white
sometimes:

  if deep || !FileTest.exist?(smallFileName) ||
             File.mtime(filename) >= File.mtime(smallFileName)
    image = Magick::ImageList.new(filename)
    thumb = nil
    image.change_geometry('160x120') do |cols, rows, img|
      thumb = img.resize cols, rows
    end
    white_bg = Magick::Image.new(160, 120)
    image = white_bg.composite(thumb, Magick::CenterGravity,
Magick::OverCompositeOp)

    if isMovie filename
      playArrow = Magick::Draw.new
      playArrow.stroke('black').stroke_width(2).fill('lime')
      playArrow.polygon(7,7, 27,17, 7,27)
      playArrow.draw image
    end

    image.write(smallFileName) { self.quality = 85 }
  end

Chris