. Logarithms are usually computed to the base of 10 and are used for shortening mathematical calculations-e.g. 10³ = 1,000. Logarithmic Quantization A digital audio encoding method that yields 12-bit Step Encoding accuracy using only eight-bit encoding. It is a technique used in CCITT G.711 audio. loop filter H.261 codecs break an original video field into 8-x-8 pixel blocks, then filters and compresses each block. A loop filter is used to separate the images' spatial frequencies SO that they can be uniquely compressed. lossless compression Techniques that, when they are reversed, yield data identical to the original. lossy compression A compression technique that, when reversed, contains less information than the original image. Techniques that, when reversed, do not yield data that is identical to the original. Lossy compression techniques are good at compressing motion video sequences and achieve much higher compression ratios than lossless techniques. low-pass filter A device that attenuates the frequencies above the cut-off point and which is used in sound synthesis and digital audio sampling. Large Scale Integration. Refers to degree of miniaturization achieved in manufacturing complex integrated circuits. The brightness signal in a video transmission. lumen A measure of light emitted by a source. luminance The information about the varying light intensity of an image produced by a television or video camera. Also called brightness. Video Communication: the Whole Picture A contraction of luminance and flux and a basic unit for measuring light intensity. A Lux is approximately 10 foot candles. Lempel-Ziv-Welch coding developed by three mathematicians in the 1970s. LWZ looks at repetitive bit combinations and represents the most commonly occurring sequences with abbreviated codes. Multiple Analog Component, one of the original European HDTV formats. In data networking, media access controllers are the interface between an application and an output device. macroblock In H.261 encoding, a macroblock is made up 