Class: WizRtf::Image

Inherits:
Object
  • Object
show all
Defined in:
lib/wiz_rtf/image.rb

Constant Summary collapse

JPEG_SOF_BLOCKS = 
[0xC0, 0xC1, 0xC2, 0xC3, 0xC5, 0xC6, 0xC7, 0xC9, 0xCA, 0xCB, 0xCD, 0xCE, 0xCF]
PIC_TYPE = 
{png: :pngblip, jpg: :jpegblip, bmp: :pngblip, gif: :pngblip}

Instance Method Summary collapse

Constructor Details

#initialize(file) ⇒ Image

Returns a new instance of Image.



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# File 'lib/wiz_rtf/image.rb', line 12

def initialize(file)
  begin
    @img = IO.binread(file)
    @width, @height = self.size
  rescue  Exception => e
    STDERR.puts "** error parsing #{file}: #{e.inspect}"
  end
end

Instance Method Details

#render(io) ⇒ Object 



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# File 'lib/wiz_rtf/image.rb', line 67

def render(io)
  io.group do
    io.cmd '*'
    io.cmd 'shppict'
    io.group do
      io.cmd :pict
      io.cmd PIC_TYPE[@type]
      io.cmd :picscalex, 99
      io.cmd :picscaley, 99
      io.cmd :picw, @width
      io.cmd :pich, @height
      io.write "\n"
      @img.each_byte do |b|
        hex_str = b.to_s(16)
        hex_str.insert(0,'0') if hex_str.length == 1
        io.write hex_str
      end
      io.write "\n"
    end
  end if @img
end

#size ⇒ Object 



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# File 'lib/wiz_rtf/image.rb', line 42

def size
  case self.type
    when :gif
      @img[6..10].unpack('SS')
    when :png
      @img[16..24].unpack('NN')
    when :bmp
      d = @img[14..28]
      d.unpack('C')[0] == 40 ? d[4..-1].unpack('LL') : d[4..8].unpack('SS')
    when :jpg
      d = StringIO.new(@img)
      section_marker = 0xff # Section marker.
      d.seek(2) # Skip the first two bytes of JPEG identifier.
      loop do
        marker, code, length = d.read(4).unpack('CCn')
        fail "JPEG marker not found!" if marker != section_marker
        if JPEG_SOF_BLOCKS.include?(code)
          #@bits, @height, @width, @channels = d.read(6).unpack("CnnC")
          return d.read(6).unpack('CnnC')[1..2].reverse
        end
        d.seek(length - 2, IO::SEEK_CUR)
      end
  end
end

#type ⇒ Object 



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# File 'lib/wiz_rtf/image.rb', line 21

def type
  png = Regexp.new("\x89PNG".force_encoding("binary"))
  jpg = Regexp.new("\xff\xd8\xff\xe0\x00\x10JFIF".force_encoding("binary"))
  jpg2 = Regexp.new("\xff\xd8\xff\xe1(.*){2}Exif".force_encoding("binary"))

  @type = case @img
            when /^GIF8/
              :gif
            when /^#{png}/
              :png
            when /^#{jpg}/
              :jpg
            when /^#{jpg2}/
              :jpg
            when /^BM/
              :bmp
            else
              :unknown
          end
end