PPM Image File Format

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PPM Image File Format
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The Portable Pixmap (PPM) File Format

• This is the ASCII file format
• P3
• feep.ppm
• 4 4
• 255
• 0 0 0 0 0 0 0 0 0 14 0 5
• 0 0 0 0 62 7 0 0 0 0 0 0
• 0 0 0 0 0 0 0 63 7 0 0 0
• 15 0 78 0 0 0 0 0 0 0 0 0

Magic Number (identifies the file
type) Comment Width Height Maximum
Intensity Pixel Data Topleft
image RGB 0Max
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Binary PPM File Format

• Format Difference
• The magic number is P6, instead of P3
• Pixel values stored as bytes, instead of ASCII
  decimal
• A single whitespace character (typically
  newline) follows the maximum intensity
• No whitespace allowed in the pixel data area
• Files are smaller Þ many times faster to read
  and write
• Note that this raw format can only be used for
  intensities less than or equal to 255

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Some Useful Unix Image Utilities
Converters convert giftoppm, ppmtogif ppmtopict,
picttoppm ppmtotga, tgatoppm
Viewers display gqview gimp