1<HTML> 2<HEAD> 3<TITLE> 4Introduction to the TIFF Documentation 5</TITLE> 6</HEAD> 7<BODY BGCOLOR=white> 8<FONT FACE="Arial, Helvetica, Sans"> 9<H1> 10<IMG SRC=images/strike.gif WIDTH=128 HEIGHT=100 ALIGN=left HSPACE=6> 11Introduction to the TIFF Documentation 12</H1> 13 14 15<P> 16The following definitions are used throughout this documentation. 17They are consistent with the terminology used in the TIFF 6.0 specification. 18 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. 40</UL> 41 42<P> 43In order to better understand how TIFF works (and consequently this 44software) it is important to recognize the distinction between the 45physical organization of image data as it is stored in a TIFF and how 46the data is interpreted and manipulated as pixels in an image. TIFF 47supports a wide variety of storage and data compression schemes that 48can be used to optimize retrieval time and/or minimize storage space. 49These on-disk formats are independent of the image characteristics; it 50is the responsibility of the TIFF reader to process the on-disk storage 51into an in-memory format suitable for an application. Furthermore, it 52is the responsibility of the application to properly interpret the 53visual characteristics of the image data. TIFF defines a framework for 54specifying the on-disk storage format and image characteristics with 55few restrictions. This permits significant complexity that can be 56daunting. Good applications that handle TIFF work by handling as wide 57a range of storage formats as possible, while constraining the 58acceptable image characteristics to those that make sense for the 59application. 60 61 62<P> 63<HR> 64 65Last updated: $Date: 2016-09-25 20:05:44 $ 66 67</BODY> 68</HTML> 69