These compression methods require very little effort to compress and decompress. Standard general-purpose compression tools cannot significantly compress JPEG files. Some compression functions do not compress by half, but instead by some other factor. YUI Compressor or Pretty Diff, can compress CSS files. Software can compress each bitmap in a bitmap index to save space. Cars dynamically compress and deform around objects they crash into. It's provably impossible to create an algorithm that can losslessly compress any data. The Unarchiver does not compress files. It offers free services to compress, convert and edit PDF documents. This requires considerable effort to compress the stack in the silo to cure it properly. Alternatively, a stationary or on-board compressor can compress air on demand, possibly requiring several hours. Some scanners compress and clean up the image using embedded firmware. More common compressors can compress this better. Shock loads cause the oil to compress the gas. The rice would compress and merge during the cooking process.