Abstract: A source coder exploits the spatial and temporal masking properties of a LCD flat panel display to improve perceptual quality over a limited bandwidth channel. The LCD's black matrix generates a strong noise component centered at the Nyquist frequency that masks the portion of the signal spectrum that lies near the Nyquist frequency. The sluggish response times of liquid crystals creates a temporal mask that further reduces the spatial resolution of moving objects. In response, the source coder shifts bits from masked transform coefficients to unmasked coefficients thereby improving the perceived visual quality of the reconstructed image. The image coder can also be designed to match the color depth associated with the LCD.

Abstract: A method and an apparatus for driving a passive liquid crystal display to obtain a high contrast ratio for both still image and video modes includes driving some or all of the row lines simultaneously. The row voltage wave forms are defined as a set of orthogonal functions and the column voltage wave forms are defined as a linear combination of the row voltages. The mean square voltage across each pixel and row is specified, and the corresponding column coefficient is calculated from which all coefficients in a column can be determined.

Abstract: The inventive method calculates the column coefficients for a liquid crystal display panel. By using this method, the invention shows that the select/nonselect ratio can be maximized by the following ways: (1) Scaling the image to the maximally physically realizable select/nonselect ration via the following equation ##EQU1## (2) Choosing an optimum value for row rms voltage "F", (3) Altering the statistics of an image, to reduce the variance of the different columns and/or increase the average of the columns, (4) Altering an image through fastest ascent or minimal error methods and (5) Designing the image to be predominantly at high rms voltage states. The select/nonselect ratio determines the available voltage range to achieve gray scale or variation in intensity. By maximizing the select/nonselect ratio, the present invention is able to obtain a wider range of intensity variation, i.e. larger contrast ratio.

Abstract: Data which represents an animation sequence of a three dimensional object at a series of discrete time frames is compressed by identifying characteristic features of the object; generating a quadrangular mesh representation of the object, whereby the object is mathematically defined by dividing it into one or more regions and hierarchically representing each region by a mesh, each mesh including three coordinate matrices which define the positions of nodes within the mesh; selecting from the mesh representation of the features a set of animation parameters which are capable of specifying changes in the mesh corresponding to the animation of the object; compressing each region mesh by applying pyramid progressive coding to the coordinate matrices for the mesh; storing the initial values for the animation parameters at the beginning of the animation sequence; and, at each time frame after the beginning of the animation sequence, estimating the current values of the parameters and compressing each parameter by e