Nonuniform quantizers for just-not-visible reconstruction errors in an adaptive intra-/interframe DPCM (digital pulse-code modulation) scheme for component-coded color television signals are presented, both for conventional and for noise-shaping DPCM. Noise feedback filters that minimize the visibility of reconstruction errors by spectral shaping are designed for Y, R-Y, and B-Y. A closed-form description of the masking function is derived which leads to a one-parameter b-quantizer characteristic. Subjective tests that were carried out to determine visibility thresholds for reconstruction errors for conventional DPCM and for noise shaping DPCM show significant gains by noise shaping. For a transmission rate of around 30 Mb/s, reconstruction errors are almost always below the visibility threshold if variable length encoding of the prediction error is combined with noise shaping within a 3:1:1 system.>

CTIP (CT Image Processing) package is an on-line image processing software developed through the CT scanner's computer system for manipulating CT scans. The purpose of developing such an on-line system is to minimize the disadvantages from the off-line processing method, namely, the requirement of an additional image processing hardware in order to be interactive, the tediousness in handling pictorial input and output transfer, and the difficulty in using it in a clinical environment. The architecture and operating procedure of the CTIP are first given. Program descriptions together with their applications are then followed.