Abstract: An electronic paintbrush and electronic palette which allow a user to generate images on a CRT screen in a manner which imitates traditional painting with paints on a canvas. The electronic brush has fiber optic bristles which channel light from a CRT screen to optical detectors. A microprocessor in the brush utilizes pulses generated by the incidence of the raster scan on photodiodes to determine the position of the brush, the pressure of the brush against the CRT screen, and its angular orientation about the longitudinal axis of the brush. The microprocessor utilizes color information generated by a CCD array to determine the area of contact of the brush with color swatches on the palette, and the angle between the longitudinal axis of the brush and the normal vector to the CRT screen. In an alternate embodiment the palette is also displayed on the CRT screen.

Abstract: Transforms such as the DCT are useful for image compression. One close relative of the DCT is preferred for its arithmetic simplicity. A method and apparatus is described whereby the quantization operates with speeds comparable to 16 bit transforms yet the mean squared error is comparable to that of a 32 bit transform. The factorability of the transform into a relatively rapid set of additions and a set of multiplications permits an efficient pipelined data flow wherein the addition sections of the vertical and horizontal transforms are performed by the same hardware prior to a final multiplication.

Abstract: An electronic paintbrush and electronic palette which allow a user to generate images on a CRT screen in a manner which imitates traditional painting with paints on a canvas. The electronic brush has fiber optic bristles which channel light from a CRT screen to optical detectors. A microprocessor in the brush utilizes pulses generated by the incidence of the raster scan on photodiodes to determine the position of the brush, the pressure of the brush against the CRT screen, and its angular orientation about the longitudinal axis of the brush. The microprocessor utilizes color information generated by a CCD array to determine the area of contact of the brush with color swatches on the palette, and the angle between the longitudinal axis of the brush and the normal vector to the CRT screen. In an alternate embodiment the palette is also displayed on the CRT screen.

Abstract: In an image compression system using a typical image compression scheme, a pointer array is provided to point to each of the many MCUs in a compressed image file. From all the blocks of an image, a subset of the blocks is selected as a virtual image. The virtual image is edited, and each edited block is compressed into an edited block. The edited block is compressed into an edited MCU and placed in an edited block region, and the pointer to the original MCU is changed to point to the new MCU. In this way, the pointer array can be modified to perform an Undo operation. An edge table is provided to hold values where each value, when combined with the differential value for a block on the edge of the virtual image, provides an absolute value for the block without reference to blocks beyond the edge of the virtual image. The entries in the edge table are determined from the compressed MCUs without the blocks being fully decompressed. More than one edge table can be provided.

Abstract: In an image compression system using a typical image compression scheme, a pointer array is provided to point to each of the many MCUs in a compressed image file. From all the blocks of an image, a subset of the blocks is selected as a virtual image. The virtual image is edited, and each edited block is compressed into an edited block. The edited block is compressed into an edited MCU and placed in an edited block region, and the pointer to the original MCU is changed to point to the new MCU. In this way, the pointer array can be modified to perform an Undo operation. An edge table is provided to hold values where each value, when combined with the differential value for a block on the edge of the virtual image, provides an absolute value for the block without reference to blocks beyond the edge of the virtual image. The entries in the edge table are determined from the compressed MCUs without the blocks being fully decompressed. More than one edge table can be provided.

Abstract: A two-dimensional shift array for use in image compression VLSI techniques. The present invention utilizes a two-dimensional shift array which provides a significant savings in terms of required silicon area over a conventional implementation.

Abstract: An improved method for converting between two color spaces such as the RGB and YIQ color on a 32 bit microprocessor. The present invention only requires in total number of operations three table look-ups, two adds, two barrel shifts and two masking operations. In terms of speed it is believed that the present invention is optimal for microprocessors such as 32 bit microprocessors.

Abstract: A novel quantization method for use in image compression techniques provides a 3-6% improvement in compression which is achieved with minimal additional hardware or software and yet which is compatible with proposed standard techniques.

Abstract: A color image compression system and method provides an improved technique of combining various image processing techniques to obtain high quality color image compression. The present invention provides color image compression, especially high quality original images that require up to 24 bits of data per pixel. The present invention utilizes a delta quantizing technique between an array of pixels to provide an improved color image compression aspect.

Abstract: One or more power dimmers have a preshaped phase controlled input signal connected to their control input. The preshaped phase controlled input signal is generated from the output of a master dimmer having conventional phase control circuits operated from a manual or other control. A relay having contacts in the output circuit of the power dimmers is opened in response to the reduction of the phase controlled input signal to a value less than a given value. In an alternative embodiment, the power dimmers are replaced by an interface circuit which produces a variable frequency, pulse width modulated or other signal.