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Introduction to the TIFF Documentation
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Introduction to the TIFF Documentation
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The following definitions are used throughout this documentation.
They are consistent with the terminology used in the TIFF 6.0 specification.

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<DT><I>Sample</I>
<DD>The unit of information stored in an image; often called a
  channel elsewhere.  Sample values are numbers, usually unsigned
  integers, but possibly in some other format if the SampleFormat
  tag is specified in a TIFF
<DT><I>Pixel</I>
<DD>A collection of one or more samples that go together.
<DT><I>Row</I>
<DD>An Nx1 rectangular collection of pixels.
<DT><I>Tile</I>
<DD>An NxM rectangular organization of data (or pixels).
<DT><I>Strip</I>
<DD>A tile whose width is the full image width.
<DT><I>Compression</I>
<DD>A scheme by which pixel or sample data are stored in
  an encoded form, specifically with the intent of reducing the
  storage cost.
<DT><I>Codec</I>
<DD>Software that implements the decoding and encoding algorithms
  of a compression scheme.
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In order to better understand how TIFF works (and consequently this
software) it is important to recognize the distinction between the
physical organization of image data as it is stored in a TIFF and how
the data is interpreted and manipulated as pixels in an image.  TIFF
supports a wide variety of storage and data compression schemes that
can be used to optimize retrieval time and/or minimize storage space.
These on-disk formats are independent of the image characteristics; it
is the responsibility of the TIFF reader to process the on-disk storage
into an in-memory format suitable for an application.  Furthermore, it
is the responsibility of the application to properly interpret the
visual characteristics of the image data.  TIFF defines a framework for
specifying the on-disk storage format and image characteristics with
few restrictions.  This permits significant complexity that can be
daunting.  Good applications that handle TIFF work by handling as wide
a range of storage formats as possible, while constraining the
acceptable image characteristics to those that make sense for the
application.


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<ADDRESS>
<A HREF="sam.html">Sam Leffler</A> / <A HREF="mailto:sam@engr.sgi.com">sam@engr.sgi.com</A>.
Last updated: $Date: 1996/04/29 19:18:06 $
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