A system for storing video information at both a slow scan rate and a fast scan rate, and for retrieving video information signals from the stored information at both the slow scan rate and the fast scan rate. A random access memory stores information provided by digital video information signals. An address selector addresses a selected location in the memory. A slow scan counter provides a count at the slow scan rate. The slow scan count is provided to the address selector for indicating the selected location to be addressed in the memory when either storing or retrieving information at the slow scan rate. A fast scan counter provides a count at the fast scan rate. The fast scan count is provided to the address selector for indicating the selected location to be addressed in the memory when either storing or retrieving information at the fast scan rate. An address selection control responds to the fast scan counter for causing the address selector to address the selected locations in the memory indicated by the count provided by the fast scan counter during intervals corresponding to one line of video information provided at the fast scan rate, and to address the selected locations in the memory indicated by the count provided by the slow scan counter during blanking intervals between the video line intervals.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 651,517 now abandoned, filed Jan. 22, 1976 as a continuation of application Ser. No. 571,084, filed Apr. 24, 1975 (now abandoned).
A method and system for translating between three complementary color component slow scan video signals and a composite color slow scan video signal containing a frequency modulated (FM) luminance information signal within a first frequency range of the slow scan video signal frequency band and an FM chrominance information signal within a separate second frequency range of the slow scan video signal frequency band, wherein the chrominance information signal includes a first color difference signal derived by subtracting the luminance information signal from one of three complementary color slow scan video signals and a second color difference signal derived by subtracting the luminance information signal from another of three complementary color slow scan video signals. The three complementary color component slow scan video signals are translated into the composite color slow scan video signal for transmission. Upon reception, the composite signal is translated into the three complementary signals for provision to a three memory slow-to-fast scan converter.
A color slow-scan TV system and method are disclosed for selecting U.S. standard NTSC TV color pictures (or alternately other standards such as PAL or non-standard color TV) to be transmitted, transmitting the selected pictures utilizing slow-scan techniques, and reconstructing the pictures after transmission for display. The system includes a video compressor (transmitter) for receiving a composite video signal indicative of a color TV picture and providing therefrom a color slow-scan output signal indicative thereof, and a video expander (receiver) for receiving color slow-scan signals after transmission and providing therefrom a fast-scan output signal suitable for display of the color TV picture. The system and method include digitizing a selected video signal indicative of a TV color picture, writing the digitized information into a digital memory, reading out the memory through a digital-to-analog converter at a color slow-scan rate suitable for transmission on a transmission channel, receiving the transmitted color slow-scan signal and digitizing the received color slow-scan signal, writing the digitized color slow-scan information into a digital memory, and reading out the memory through a digital-to-analog converter at a fast-scan rate suitable for display on conventional color TV monitors using NTSC, PAL, or other standards.
A baggage inspection system utilizing fluoroscopy of baggage pieces and the like, employing an X-Ray flash unit, a television pick-up unit for scanning the X-Ray image, storage of the television image and subsequent image reproduction by a television monitor, in which, in accordance with the invention, the memory is a digital solid state memory for the digital storage of a half frame, of an interlaced video frame of the television pick-up unit, with a capacity of 6 to 8 bits per image-point of the image signal to be stored.
To provide improved resolution of a television, e.g. CRT, display with reduced large-area flicker, twittering of horizontal edges, and line structure of the picture, the field rate is doubled and the number of lines per field is doubled from that of a received input television signal. Preferably a 21/2 field store arranged in half-field units is used, together with a four-line store arranged in one line units to provide line interpolation, which can be adaptively dependent upon the presence or absence of motion.
An image coding apparatus for sequentially coding an input image signal that is supplied at a predetermined frame rate at a rate that is independent of such a frame rate, thereby obtaining a coding image signal for transmission from which frames are thinned out. The apparatus comprises: a frame memory having a recording area corresponding to one frame of the input image signal to store the input image signal; a write address generator to sequentially generate write addresses in the frame memory in correspondence to the input image signal; a coder to execute a coding process by using the signal which is read out from the frame memory; a read address generator to sequentially generate read addresses in the frame memory in response to a frame change request which is generated from the coder; and a write limiter for comparing the write address and the read address, for stopping the subsequent writing operation of the frames written in the frame memory when the write address approaches the read address, and for restarting the writing operation from the head of the next frame.
