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5 Compression
In general, pictures are not homogeneous. Areas of soft texture can lie
adjacent to flat areas or contrasting areas. In Section 4.4 we have indicated
that the visual response to noise changes markedly between these areas. In
view of this, greater compression efficiencies can be achieved if the param-
eters of a compression algorithm are changed according to the local charac-
teristics of the picture. Such adaptive compression techniques have been
investigated by Anderson and Huang [3], Tasto and Wintz [85], Hayes [38],
Limb [52], and Chen and Smith [9].
Other topics that were not covered in this chapter or were only briefly ...