Lossy compression is most commonly used to compress multimedia data audio, video, and images, especially in applications such as streaming media and internet telephony. Jpeg is a lossy format that offers a higher compression. Lossless compression there is no loss of information from image. There are several compression techniques, but the main two categories are lossless and lossy compression techniques. A lossy compression scheme, shown in figure, may examine the color data for a range of pixels, and identify subtle variations in pixel color values that are so minute that the human eyebrain is unable to distinguish the difference between them. Because the data is preserved, the technique will decompress the data and restore it exactly to its original state. Research trends of multimedia compression techniques 10. The jpeg image file, commonly used for photographs and other complex still images on the web, is an image that has lossy compression. Lossy compression definition, multimedia data compression lossy compression, instead, works identifying unnecessary or less relevant information not just redundant data and removing it. Unlike lossy compression, no data is lost when this method is used. 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 are removed forever. Jpeg 4 modes of compression lossy sequential dctbased mode baseline mode.
Multimedia compression techniques information technology. Lossless compression an overview sciencedirect topics. Lossless compression is used in text, images, sound. Unlike the lossless compression, the amount of information to compress is effectively reduced. This is my lecture number 51 for multimedia series. A compression technique that does not decompress digital data back to 100% of the original. A data compression technique for multimedia applications article pdf available in journal of scientific and industrial research 6512 december 2006 with 330 reads how we measure reads. Software andor hardwareassisted implementation requirements. The next several chapters deal with lossy compression algorithms as they are commonly used for image, video, and audio compression. Lossless gives 100% recovery data from the original data on the other hand the lossy compression technique gives a high compression ratio 59. Lossy compression techniques lossycompressionvectorquantizationbylindebuzogray lossy compression technique provides higher compression ratio than lossless compression. Run length encoding, lempelzivwelch, huffman coding, arithmetic encoding etc. Lossy compression and lossless compression algorithms.
85 1267 723 301 933 320 1184 316 857 1169 384 124 808 790 635 592 282 907 1238 1409 132 152 1331 1227 499 267 162 1321 31 1204 589 1189 58 1269 1098 105 1348 637 447 169 347 1153 784