src/tiff/html/intro.html

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   4 Introduction to the TIFF Documentation
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  11 Introduction to the TIFF Documentation
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  16 The following definitions are used throughout this documentation.
  17 They are consistent with the terminology used in the TIFF 6.0 specification.
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  19 <DL>
  20 <DT><I>Sample</I>
  21 <DD>The unit of information stored in an image; often called a
  22   channel elsewhere.  Sample values are numbers, usually unsigned
  23   integers, but possibly in some other format if the SampleFormat
  24   tag is specified in a TIFF
  25 <DT><I>Pixel</I>
  26 <DD>A collection of one or more samples that go together.
  27 <DT><I>Row</I>
  28 <DD>An Nx1 rectangular collection of pixels.
  29 <DT><I>Tile</I>
  30 <DD>An NxM rectangular organization of data (or pixels).
  31 <DT><I>Strip</I>
  32 <DD>A tile whose width is the full image width.
  33 <DT><I>Compression</I>
  34 <DD>A scheme by which pixel or sample data are stored in
  35   an encoded form, specifically with the intent of reducing the
  36   storage cost.
  37 <DT><I>Codec</I>
  38 <DD>Software that implements the decoding and encoding algorithms
  39   of a compression scheme.
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  43 In order to better understand how TIFF works (and consequently this
  44 software) it is important to recognize the distinction between the
  45 physical organization of image data as it is stored in a TIFF and how
  46 the data is interpreted and manipulated as pixels in an image.  TIFF
  47 supports a wide variety of storage and data compression schemes that
  48 can be used to optimize retrieval time and/or minimize storage space.
  49 These on-disk formats are independent of the image characteristics; it
  50 is the responsibility of the TIFF reader to process the on-disk storage
  51 into an in-memory format suitable for an application.  Furthermore, it
  52 is the responsibility of the application to properly interpret the
  53 visual characteristics of the image data.  TIFF defines a framework for
  54 specifying the on-disk storage format and image characteristics with
  55 few restrictions.  This permits significant complexity that can be
  56 daunting.  Good applications that handle TIFF work by handling as wide
  57 a range of storage formats as possible, while constraining the
  58 acceptable image characteristics to those that make sense for the
  59 application.
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  65 Last updated: $Date: 1999/08/09 20:21:21 $
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