Difference Between Lossy And Lossless Compression

What Is Lossy Compression?

Lossy compression also referred to as irreversible compression is the class of data encoding methods that uses inexact approximations and partial data discarding to represent the content. In other words, it is a method of data compression in which the size of file is reduced by eliminating data in the file. In doing so, image quality is sacrificed to decrease file size. Any data that the compression algorithm deems expendable is removed from the image, thereby reducing its size. These techniques are used to reduce data size for storing, handling and transmitting content.

Lossy methods can provide high degrees of compression and result in smaller compressed files, but some number of the original pixels, sound waves or video frames is removed forever. Examples are the widely used JPEG image, MPEG video and MP3 audio formats. Lossy compression is never used for business data and text, which demand a perfect restoration.

What You Need To Know About Lossy Compression

• Lossy compression is also referred to as irreversible compression.
• Lossy compression is a data encoding method that utilizes imprecise estimates to represent the content.
• It is used for application that can tolerate difference between the original and reconstructed data.
• Data that has been compressed using this technique can’t be recovered and reconstructed exactly.
• Lossy data compression mainly supports JPEG, GIF, MP3, MP4, MKV and OGG file types.
• File quality is low in lossy data compression.
• Lossy compression is mainly used to compress audio, video and images.
• Algorithms used in Lossy compression are: Transform coding, Discrete Cosine Transform, Discrete Wavelet Transform, fractal compression etc.
• Lossy compression reduces the size of the file to large extent.
• Lossy compression method has high data holding capacity.
• In lossy data compression, there is a loss of quality and data, which is not measurable.
• Compression rate is high.

What Is Lossless Compression?

Lossless compression also referred to as reversible compression, is a data compression algorithm that permits data to be accurately reconstructed from the compressed data. Lossless compression is used in cases where it is important that the original and the decompressed data be identical or where deviations from the original data would be unfavorable.

As the name suggests, the technique involves no loss of information, the original data can be recovered exactly from the compressed data after a compressed/expand cycle. Basically lossless technique rewrites the data of the original file in a more efficient way. Lossless compression is generally used for the so-called ‘’discrete’’ data, such as database records, spreadsheets, word-processing files and even some kinds of image and video information.

Lossless data compression is used in many applications. For example, it is used in the ZIP file format and in the GNU tool gzip. It is also often used as a component within lossy data compression technologies (e.g lossless mid/side joint stereo preprocessing by MP3 encoders and other lossy audio encoders).

What You Need To Know About Lossless Compression

• Lossless Compression is also termed as reversible compression.
• Lossless compression is a data compression algorithm that permits data to be accurately reconstructed from the compressed data.
• It is used for application that can’t tolerate any difference between original and reconstructed data.
• If data has been (lossless) compressed, the original data can be recovered from the compressed data.
• Lossless data compression mainly supports RAW, BMP, PNG, WAV, FLAC and ALAC file types.
• File quality is high in lossless data compression.
• Lossless compression is mainly used to compress text-sound and images.
• Algorithms used in Lossless compression are: Run Length Encoding, Lempel-Ziv-Welch, Huffman Coding, Arithmetic encoding, Shannon Fano coding etc.
• Lossless compression reduces the size but less as compared to lossy compression.
• Lossless compression has low data holding capacity as compared to lossy compression.
• In lossless data compression, there is no loss of any data and quality.
• Compression rate is small.

Also Read: Difference Between MP3 And MP4 Format

Difference Between Lossy And Lossless Compression In Tabular Form