freeswitch/libs/tiff-4.0.2/html/intro.html

69 lines
2.3 KiB
HTML

<HTML>
<HEAD>
<TITLE>
Introduction to the TIFF Documentation
</TITLE>
</HEAD>
<BODY BGCOLOR=white>
<FONT FACE="Arial, Helvetica, Sans">
<H1>
<IMG SRC=images/strike.gif WIDTH=128 HEIGHT=100 ALIGN=left HSPACE=6>
Introduction to the TIFF Documentation
</H1>
<P>
The following definitions are used throughout this documentation.
They are consistent with the terminology used in the TIFF 6.0 specification.
<DL>
<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.
</UL>
<P>
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.
<P>
<HR>
Last updated: $Date: 1999-08-09 20:21:21 $
</BODY>
</HTML>