Lossless compression

A process that reduces the storage space needed for an image file without loss of data. If a digital image that has undergone lossless compression is decompressed, it will be identical to the digital image before it was compressed. Document images (i.e. in black and white, with a great deal of white space) undergoing lossless compression can often be reduced to one-tenth their original size; continuous tone images under lossless compression can seldom be reduced to one-half or one-third of their original size.Also see lossy compression.