Go Pdf

PDF stands for Portable Document Format. It is a file format for exchange of documents which was designed in 1993 by Adobe. It is a file system which is generally used for the representation of two dimensional objects. THe PDF file contains the complete layout description of the two dimensional object. in its early days was not freely available. But after passage of times Adobe make it available to the users without any cost. Since from 1993 eight different versions of Acrobat Adobe have been released.

PDF 1.0 / Acrobat 1.0 - It was release in 1993

PDF 1.1 / Acrobat 2.0 - It was released in 1994

PDF 1.2 / Acrobat 3.0 - This version was released in 1996

PDF 1.3 / Acrobat 4.0 - Released in 1999

PDF 1.4 / Acrobat 5.0 - It was released in 2001

PDF 1.5 / Acrobat 6.0 - came in market in 2003

PDF 1.6 / Acrobat 7.0 - Available in market in 2005

PDF 1.7 / Acrobat 8.0 - It was released in 2006

PDF 1.7 / Acrobat 9.0 - This was released in 2008

Adobe bears the patent for PDF file system but has given permissions for its use. So anyone can create a PDF application. THe PDF is a combination of three technologies:

Post script Programming language to generate layouts and styles.

Font embedding system so tha fonts can travel within various documents.

A strorage system to combine all the files and the related contents in a single package provided with data compression technique wherever necessary.

PDF File Structure: A PDF file consists of eight data types

Name

String

Boolean

NULL object

Strings

Streams

Dictionaries

Arrays

Two layouts are defined for a PDF file. THe first one is linear layout and the other one is non linear layout. The non linear PDF layouts utilize less disk space than linear layouts. But the disadvantage with non linear layouts is that the access time is more because the data is randomly scattered over the PDF file while the linear layout provides a less time for data access because the data is uniformly scattered in the file.