What are lossless and lossy compression?

It's likely that you've heard the terms "lossless" and "lossy" compression before, but what do they actually mean and which is right for you? Read on to find out!

 

What is lossless compression?

Lossless compression is a type of compression that allows data to be reduced without any loss of quality. This is in contrast to lossy compression (see below), which sacrifices some data in order to achieve greater levels of compression. Lossless compression is often used for files that are not meant to be altered, such as images and audio files. One example of a lossless compression algorithm is the Lempel-Ziv-Welch (LZW) algorithm, which is commonly used for image files. Although lossless compression typically results in smaller file sizes than lossy compression, it is often more computationally intensive, making it less practical for real-time applications.

 

What is lossy compression?

Lossy compression is a type of data compression in which some original data is lost during the encoding process. This is in contrast to lossless compression, which does not lose any data. Lossy compression is often used for images and audio files, where some loss of quality is acceptable in exchange for a smaller file size. The most common type of lossy compression is JPEG, which is used for photos and images. When choosing between lossless and lossy compression, it is important to weigh the trade-off between file size and quality.

 

The main difference between lossless annd lossy compression

As you can read above, lossless and lossy compression are two methods used to reduce the size of digital files. As the name suggests, lossless compression preserves all the data in a file, while lossy compression removes some of the data.  Lossy compression is often used for files like audio and video, where some minor degradation in quality is acceptable. Lossy compression can achieve much higher levels of compression than lossless, but it is not suitable for all types of files. In general, lossy compression is best for images and audio files, while lossless compression is better for text and other types of data.

 

Lossy or lossless compression for audio files?

One of the most important choices to make when compressing audio files is whether to use lossy or lossless compression. Both types of compression have their advantages and disadvantages. Lossy compression is much more efficient, resulting in smaller file sizes, but it can also cause a degradation in sound quality. Lossless compression preserves the full quality of the original audio, but the files are much larger and take longer to compress. Ultimately, the choice between lossy and lossless compression depends on the needs of the user. For example, if storage space is limited, lossy compression may be the best option, even if it means sacrificing some sound quality. On the other hand, if it is essential to retain the full fidelity of the original recording, lossless compression is the only way to go.

 

Lossy or lossless compression for image files?

When compressing an image file you also have the choice between lossy or lossless compression. With lossy compression, some of the data from the original file is removed, resulting in a smaller file size. However, this also means that the quality of the image is reduced. Lossless compression, on the other hand, does not remove any data from the original file. As a result, the file size is reduced, but the quality of the image is maintained. When deciding which type of compression to use, it is important to consider the desired outcome. If file size is more important than quality, then lossy compression may be the better option. However, if maintaining image quality is a priority, then lossless compression is the better choice.

The best audio format for high sound quality

Audio files come in many, many formats like MP3, WAV, FLAC. What file format your choose for your audio file is determined by more than just the audio player. For instance, there is a difference that has to be considered on whether to use lossless of lossy compressed audio files.

Lossless compressed audio

Lossless compressed audio is considered the audio form closest to the original sounds. When an audio file of your favourite band is created, you might think it consists of the sound of the vocalist, the guitarist, the bassist and the drummer, but there is more to it. Lossless means that every sound from the original take is still in the file, while still compressing the audio to a smaller file size.. The tracks on a music album, in their original form, take around 50MB of memory. A lossless compressed file contains more bits of audio data and clocks around 30MB per track. Compare that to the 4MB audio files that you know of regular audio files and you know exactly what the big difference between lossless and lossy compressed audio is.

Lossy compressed audio

This brings us to the other type of audio: lossy compressed audio. As the name indicates, these file are compressed in comparison to lossless audio files. When lossy compressed audio file are created, a process is used to discard sounds. The sounds that are left out are sounds a machine thinks the human ear cannot hear. This greatly reduces the amount of memory a track needs in order to store all its information in an audio file.

As a consequence, many people consider these audio file to be of lower quality because there are bits of the original audio missing. This is reflected by the bit rate. The more information that has been discarded from the track, the lower the bit rate. The lower the bit rare, the lower the audio quality.

The best sounding audio format

By now you have learned that for the highest quality, you will need lossless compressed audio files. Some of the best known lossless file formats are FLAC, WAV and AIFF. But which of the lossless formats delivers the best sound quality? The tracks on a music album are commonly PCM (Pulse-Coded Modulation) files. However, as been said above, these files tend to be quite large. So the music world has been looking for an answer, to make them easier to transfer.

When you ask the audiophiles, most of them will tell you that FLAC or WAV is a must. Flac retains the high quality sounds, but it still compresses the audio file by over 50%. Another advantage of the FLAC format is that it's open source. This makes it compatible with a lot of devices and applications. WAV, like AIFF, is a wrapper for a PCM file. Wrapping PCM files make them more usable and enable you to play them on devices like Windows pc's. WAV do not compress the files and leave the sound in tact.