Compressing the size of data helps to save space or transmission time. There are number of factors that determines for data compression or the transmission. It could be just the data content or on the entire transmission. It depends on how well these compression techniques are used and how efficiently the data is described. The complexity of the document ultimately determines on how large the PDF file will be. It depends on the number of fonts, forms, images and the multimedia.
The process of compression of any content can be made quite simple by removing the extra space between the characters or inserting a single repeat character. This is to indicate a string of characters that are repeated. Smaller bit strings are substituted for characters that have been used frequently. With this kind of compression a text file is reduced to half of its original size. A program that uses a formula or algorithm is applied to determine about the compression, as algorithm is one of the critical factors to determine the quality of compression.
PDF compression refers to image compressing of a PDF file. Information is compressed as much as possible and the formats are usually designed accordingly. Otherwise the data can tend to become large files. Due to the compression some information is permanently lost. It is possible that all information can be restored without any loss. Algorithms usually do not change the content of a file. The algorithms that do not lead to any loss are CCITT group 3 & 4 compression, flate compression, LZW compression, RLE compression and ZIP.
The algorithms where there are chances of losing data can be used for images or sound files. It cannot be used for text or program data. Better compression ratios are achieved by selectively getting rid of the information in the file. These algorithms are called JPEG compression. If a 7-bit ASCII representation is required, binary data produced after compression can be further converted to ASCII base-85 encoding. Another benefit of this utility is the PDF file can be decompressed to its original size for better conversion.