This papaer discribes the coding characteristics of the pixel adaptive DPCM with bit-rate prescription for data compression of still images. In pixel-adaptive DPCM, a pixel is classified into one of the eight groups according to the magnitude of the prediction error of the preceeding pixel, and the number of quantizing bits is varied adaptively to the maximum of the absolute value of the prediciton errors in each block. The coding bit-rate is successfully controlled less than the prescribed value within a tolerance by applying the pre-scanning.
A method of prescription of the bit-rate for the adaptive run-length DCT coding is described. From the total bit-rate estimated from the prescanned data of selected pixels, the step width of quantization of DCT coefficient is determined to make the coded bit-rate within the prescribed quantity. The estimation of the total bit-rate is obtained from simple additions and subtractions in order to make the estimation quickly
Our new digital card camera "VMC-1" utilizes (1) a 3-megabyte SRAM card for recording 30 field images in memory by means of adaptive DPCM type of data compression; and (2) a unique CCD read-out method of reading color signals out of an imager in the sequence of red, green, and blue in each line, 〓〓〓〓〓 this camera.
A memory card camera which records digital still images on a semiconductor memory card and peripheral equipments have been developed. The camera is equipped with a zoom lens of three magnification and contains image data compression LSIs. A memory card camera interface performs a transmission of image data on a memory card into a personal computer. The digital still camera system is expected to be widely utilized as multimedia devices.
To meet the needs such as more compact size, better picture quality and new useful functions, we developed a digital video camera system. This paper describes the development of this system. This system consists of a digital signal processing LSI(camera DSP IC), ADC, DAC and CDS/AGC IC. With using this system, we realized a very compact video camera. The camera DSP IC with 30Kgates, 14Kbit RAM and 15Kbit ROM was designed using 1μm CMOS Standard Cell tool.
We have developed digital signal processing methods for consumer-use single-CCD video cameras. And then Two types of digital signal processing CMOS LSIs for consumer-use single-CCD video cameras have been developed. The newly developed digital signal processing methods and LSIs can process the image signals that cannot be delt with the conventional analog processors. They make possible higher performance, multiple functions and smaller size of single-CCD video cameras for consumer use.
This is to report on an automatic image stabilizing system for camcorders and VCRs utilizing only video signal processing. Developed technologies for this system are, (1) BERP matching technique which can detects accurate motion vectors with a small scale circuit, (2) adaptive system control algorithm to discriminate moving objecs, (3) suppression of unsteady image motion due to noise. This reports further on new LSIs developed for realizing this system.