Portable Document Format is the most popular file format for both publishing and web purposes. When documents have to be sent over electronic mails using internet, PDF is mostly used since the size of the file is very less compared to other formats. When large hardcopy files or files in other formats are converted to PDF, their size is still pretty high. Since Internet speeds are still very slow for some consumers, large files pose a problem when they are sent as an attachment in an Electronic mail over internet. Best PDF Compression becomes the top priority for developers.
Compression is the process of converting larger files to lesser size. This is mainly done by removing data like continuous spaces and other unwanted data. This leads to decrease of file size by nearly half. There are two types of compression. Lossy and lossless are two techniques in compression. Lossless compression is one in which data is compressed and sent over the medium and it is decompressed without loss of data. This is the best PDF compression in terms of data consistency. Though there is a limit to which data can be compressed in this technique. This consistency however is not necessary for transfers where accuracy is not a main consideration. Lossless compression reduces the file size very much but results in data loss. Once data is compressed and some data is lost and can never be regained. This is the best PDF compression with respect to reducing file size.
More and more people nowadays prefer PDF as the format for transferring files. This leads to a demand for better compression algorithms. The search for the best PDF compression mainly focuses on how to reduce file size but still maintain data consistency. The level to which data consistency has to be maintained varies with the nature of transfer of file. Simple transfer of image files or simple text need not maintain data consistency. The best PDF compression algorithm should try to utilize the data patterns in the text and try to compress the data by substituting suitable data. This data can be restored to the original content during decompression.