1<HTML> 2<HEAD> 3<TITLE> 4Introduction to the TIFF Documentation 5</TITLE> 6</HEAD> 7 8<H1> 9<IMG SRC=images/strike.gif WIDTH=128 HEIGHT=100 ALIGN=left HSPACE=6> 10Introduction to the TIFF Documentation 11</H1> 12 13 14<H5> 15This documentation is best viewed using a graphical browser that supports 16the latest HTML directives for formatting documents. In particular, 17this document was authored 18for viewing with version 1.1 or newer of the 19<A HREF="http://home.mcom.com/comprod/products/navigator/index.html">Netscape Navigator</A>. 20</H5> 21 22<BR CLEAR=left> 23 24<P> 25The following definitions are used throughout this documentation. 26They are consistent with the terminology used in the TIFF 6.0 specification. 27 28<DL> 29<DT><I>Sample</I> 30<DD>The unit of information stored in an image; often called a 31 channel elsewhere. Sample values are numbers, usually unsigned 32 integers, but possibly in some other format if the SampleFormat 33 tag is specified in a TIFF 34<DT><I>Pixel</I> 35<DD>A collection of one or more samples that go together. 36<DT><I>Row</I> 37<DD>An Nx1 rectangular collection of pixels. 38<DT><I>Tile</I> 39<DD>An NxM rectangular organization of data (or pixels). 40<DT><I>Strip</I> 41<DD>A tile whose width is the full image width. 42<DT><I>Compression</I> 43<DD>A scheme by which pixel or sample data are stored in 44 an encoded form, specifically with the intent of reducing the 45 storage cost. 46<DT><I>Codec</I> 47<DD>Software that implements the decoding and encoding algorithms 48 of a compression scheme. 49</UL> 50 51<P> 52In order to better understand how TIFF works (and consequently this 53software) it is important to recognize the distinction between the 54physical organization of image data as it is stored in a TIFF and how 55the data is interpreted and manipulated as pixels in an image. TIFF 56supports a wide variety of storage and data compression schemes that 57can be used to optimize retrieval time and/or minimize storage space. 58These on-disk formats are independent of the image characteristics; it 59is the responsibility of the TIFF reader to process the on-disk storage 60into an in-memory format suitable for an application. Furthermore, it 61is the responsibility of the application to properly interpret the 62visual characteristics of the image data. TIFF defines a framework for 63specifying the on-disk storage format and image characteristics with 64few restrictions. This permits significant complexity that can be 65daunting. Good applications that handle TIFF work by handling as wide 66a range of storage formats as possible, while constraining the 67acceptable image characteristics to those that make sense for the 68application. 69 70 71<P> 72<HR> 73 74<ADDRESS> 75<A HREF="sam.html">Sam Leffler</A> / <A HREF="mailto:[email protected]">[email protected]</A>. 76Last updated: $Date: 1999-07-27 21:50:27 $ 77</ADDRESS> 78 79</BODY> 80</HTML> 81
