Glossary

Data Compression

What is Data Compression?

Data compression is the process of encoding, restructuring or otherwise modifying data in order to reduce its size. Fundamentally, it involves re-encoding information using fewer bits than the original representation.

Compression is done by a program that uses functions or an algorithm to effectively discover how to reduce the size of the data. For example, an algorithm might represent a string of bits with a smaller string of bits by using a ‘reference dictionary’ for conversion between them. Another example involves a formula that inserts a reference or pointer to a string of data that the program has already seen. A good example of this often occurs with image compression. When a sequence of colors, like ‘blue, red, red, blue’ is found throughout the image, the formula can turn this data string into a single bit, while still maintaining the underlying information.

Text compression can usually succeed by removing all unnecessary characters, instead inserting a single character as reference for a string of repeated characters, then replacing a smaller bit string for a more common bit string. With proper techniques, data compression can effectively lower a text file by 50% or more, greatly reducing its overall size.

For data transmission, compression can be run on the content or on the entire transmission. When information is sent or received via the internet, larger files, either on their own or with others, or as part of an archive file, may be transmitted in one of many compressed formats, like ZIP, RAR, 7z, or MP3.

Lossy vs Lossless

Compression is often broken down into two major forms, “lossy” and “lossless”. When choosing between the two methods, it is important to understand their strengths and weaknesses:

  • Lossless Compression: Removes bits by locating and removing statistical redundancies. Because of this technique, no information is actually removed. Lossless compression will often have a smaller compression ratio, with the benefit of not losing any data in the file. This is often very important when needing to maintain absolute quality, as with database information or professional media files. Formats such as FLAC and PNG offer lossless compression options.
  • Lossy Compression: Lowers size by deleting unnecessary information, and reducing the complexity of existing information. Lossy compression can achieve much higher compression ratios, at the cost of possible degradation of file quality. JPEG offers lossy compression options, and MP3 is based on lossy compression.

Data Compression Uses

Most businesses today rely on data compression in some major way, especially as the functional quality of data increases, storage capacity concerns have to be resolved. Data compression is one of the major tools that helps with this. There a number of file types that are frequently compressed:

  • Audio Compression: Implemented as audio codecs, compression of audio files is necessary to guarantee bandwidth and storage limits aren’t exceeded. Audio compression can be either lossy or lossless, MP3 being the most ubiquitous lossy codec. FLAC is a major lossless encoding format.
  • Video Compression: Videos combine image compression with audio compression. There are usually separate codecs for each aspect of a video, which are then wrapped together as a single compression codec. Because of the high data rate required for uncompressed video, most video files are compressed using lossy compression. The most prevalent form of (lossy) video compression is MPEG.

Why Data Compression is Important

The main advantages of compression are reductions in storage hardware, data transmission time, and communication bandwidth. This can result in significant cost savings. Compressed files require significantly less storage capacity than uncompressed files, meaning a significant decrease in expenses for storage. A compressed file also requires less time for transfer while consuming less network bandwidth. This can also help with costs, and also increases productivity.

The main disadvantage of data compression is the increased use of computing resources to apply compression to the relevant data. Because of this, compression vendors prioritize speed and resource efficiency optimizations in order to minimize the impact of intensive compression tasks.

Why Data Compression is Important

The main advantages of compression are reductions in storage hardware, data transmission time, and communication bandwidth. This can result in significant cost savings. Compressed files require significantly less storage capacity than uncompressed files, meaning a significant decrease in expenses for storage. A compressed file also requires less time for transfer while consuming less network bandwidth. This can also help with costs, and also increases productivity.

The main disadvantage of data compression is the increased use of computing resources to apply compression to the relevant data. Because of this, compression vendors prioritize speed and resource efficiency optimizations in order to minimize the impact of intensive compression tasks.

Learn More About Data Compression

Related Terms

How Barracuda Can Help

Barracuda Backup uses state-of-the-art compression technology to help minimize storage space needed for backups and recoveries. In addition, using an appliance for backups provides dedicated processing power for both data deduplication and compression.

Do you have more questions about Data Compression? Contact us today.