A hierarchical scheme with cells and modules is crucial for managing design complexity during a large integrated circuit design. We present a methodology for thermal aware cell-based electromigration analysis suitable for integrating electromigration reliability analysis into a conventional IC design flow. A block or cell is characterized for reliability while it is characterized for power and timing. Reusing cell characterization data significantly reduces computational load while analyzing a full-chip layout. During full-chip analysis, we compute a layout-level temperature profile from cell power dissipations using a Fast Fourier Transform based algorithm. The described full-chip reliability assessment methodology has been implemented in an interconnect reliability CAD tool. We have exercised the tool to demonstrate performance-reliability tradeoff and the significance of thermal-aware reliability analysis for true reliability aware design.

Progressive transmission hierarchically reorganizes the information in an image with the aim of increasing transmission efficiency on a low bandwidth channel. We have developed methods for adaptively choosing initial and successive approximations to be sent when the end user is a human telebrowsing through a database to find particular desired images. Because of progressive transmission overhead, it is desirable to send in one step the approximation which is just good enough to allow a user to make a positive decision (e.g., want/don't want). During past and present sessions of telebrowsing, positive response times are recorded and used to estimate the actual positive response time probability mass function. This estimate is used with a previously calculated overhead function to choose the best initial and successive approximations. We discuss the application of two-channel coding to progressive transmission and conclude that little is gained by further coding of the initial lowresolution approximation. However, the interpretation of these lowresolution images is enhanced if the displayed size is a function of image resolution. We present a method for determination of the best displayed image size which is based on the modulation transfer function of the human visual system.

The transformation of image signals between the continuous domain of the real world and the discrete domain of modern data processing can have a significant effect on quality and efficiency. Analysis based on perceptual rather than mathematical considerations has been carried out. A series of experiments based on the analysis has shown that substantial improvement over usual techniques can be achieved by the use of a cascade of a presharpening filter combined with Gaussian presampling and interpolation filters. The resulting ``sharpened Gaussian'' filter, although not exactly circularly symmetrical, gives a high degree of isotropy. Each element in the cascade is separable, so that computational efficiency is high. A favorable tradeoff is achieved among sharpness, smoothness, and the effects of aliasing. Subjective testing, in comparison with other commonly used filters, has shown the clear superiority of this filter.

The importance of enlarging and reducing two-level images such as graphical and documentary matter by digital means continues to grow as more such images are digitally represented. A nonlinear scaling scheme is devised which exploits the simplicity of this binary nature, treating images logically instead of arithmetically; a convolution-like effect is achieved without a single addition or multiplication! This method yields high-fidelity digital scaling and meets the objectives of being fast, conducive to hardware realization, and void of special pre-encoding requirements.

A multiuser multiprocessing image processing system has been developed. It is an interactive picture manipulation and enhancement facility which is capable of executing a variety of image processing operations while simultaneously controlling real-time input and output of pictures. It was designed to provide a reliable picture processing system which would be cost-effective in the commercial production environment. Additional goals met by the system include flexibility and ease of operation and modification.

The conventional DPCM compression algorithm has been substantially improved by the substitution of a tapered, noisy quantizer for the usual tapered quantizer. This markedly reduces the visibility of defects caused by granular noise and leak. The quantizer characteristic can then be modified to achieve less slope overload, thus significantly improving image quality.

The two-channel system previously reported has been implemented in hardware using system parameters appropriate to consumer television. The basic system divides the spectrum into lowand high-frequency spatial components. The lows are coarsely sampled and finely quantized and the highs finely sampled and coarsely quantized using a companded, randomized quantizer. The purpose of this experiment was to demonstrate the potential of the system for low-cost practical application, to study the effect of the character of the randomizing noise, and to ascertain that there were no deleterious effects due to interlace, motion, or input noise. Theoretical noise calculations were qualitatively confirmed.

A computer-based system for automated engraving of gravure cylinders has been developed and is now used in a normal production environment. Either fully composed pages or individual page components are scanned and stored on a large disk. In the case of fully composed pages, an operator uses a TV display to segment the page image into line and tone areas. The image is then coded by a software process and is ready for subsequent engraving. Prior to the scanning of page components, the operator uses a tablet in order to demark both cropping locations and to specify the location of the components on the final page image. The scanned components are then assembled and coded by a single software process. The encoding process reduces the data storage requirement by a factor of two without any apparent loss of quality. Data are retrieved from disk storage, buffered, decoded, transmitted to a special formatter, and used to drive a Helio Klischograph,® which engraves the cylinder in approximately one hour. Completely arbitrary imposition (the arrangement of pages on the gravure cylinder) is accomplished at the time of engraving. Provision is made for the arbitrary intermixture of computer-processed pages and conventional engraving by means of Cronapaquesgi mounted on the companion scanning machine. The motivation for this development was to reduce the cost and time required for the production of gravure cylinders.

A standard serial interfacing scheme is described. It is appropriate for the interfacing of a variety of peripherals to minicomputers, as well as for the interconnection of two or more minicomputers. The use of this serial interface simplifies the problem of compatibility of communications between computers and peripherals with different word lengths. It is quite easy for computers with different word lengths to communicate with each other without modifications of any hardware.