Coding quantized transform coefficients as occur in image compression
combines a position identifying method to identify the relative position
of clusters of consecutive non-zero-valued coefficients, an amplitude
event identifying method to identify amplitude events in the clusters of
non-zero-valued coefficients, and a coding method to code the position
events, amplitude events, and signs of the amplitudes in the clusters.
The method is particularly applicable to a series of quantized transform
coefficients where clusters are likely to occur.