数据压缩是一种在不丢失信息的情况下减少数据大小的技术。有损压缩和无损压缩是数据压缩方法的分类。
两种压缩技术(有损压缩和无损压缩)的主要区别在于，有损压缩技术不会将数据还原为原始形式，而无损压缩则是将数据还原和重建为原始形式，解压后。
有损压缩和无损压缩的区别：
| S.NO | Lossy Compression | Lossless Compression |
|---|---|---|
| 1. | Lossy compression is the method which eliminate the data which is not noticeable. | While Lossless Compression does not eliminate the data which is not noticeable. |
| 2. | In Lossy compression, A file does not restore or rebuilt in its original form. | While in Lossless Compression, A file can be restored in its original form. |
| 3. | In Lossy compression, Data’s quality is compromised. | But Lossless Compression does not compromise the data’s quality. |
| 4. | Lossy compression reduces the size of data. | But Lossless Compression does not reduce the size of data. |
| 5. | Algorithms used in Lossy compression are: Transform coding, Discrete Cosine Transform, Discrete Wavelet Transform, fractal compression etc. | Algorithms used in Lossless compression are: Run Length Encoding, Lempel-Ziv-Welch, Huffman Coding, Arithmetic encoding etc. |
| 6. | Lossy compression is used in Images, audio, video. | Lossless Compression is used in Text, images, sound. |
| 7. | Lossy compression has more data-holding capacity. | Lossless Compression has less data-holding capacity than Lossy compression technique. |
| 8. | Lossy compression is also termed as irreversible compression. | Lossless Compression is also termed as reversible compression. |