Showing papers on "Channel (digital image) published in 1980"
01 Jan 1980
TL;DR: In this paper, an approach for exploiting the tradeoffs between source and channel coding in the context of image transmission is described. But this approach does not consider the impact of channel errors.
Abstract: An approach is described for exploiting the tradeoffs between source and channel coding in the context of image transmission. The source encoder employs two-dimensional (2-D) block transform coding using the discrete cosine transform (DCT). This technique has proven to be an efficient and readily implementable source coding technique in the absence of channel errors. In the presence of channel errors, however, the performance degrades rapidly, requiring some form of error-control protection if high quality image reconstruction is to be achieved. This channel coding can be extremely wasteful of channel bandwidth if not applied judiciously. The approach described here provides a rationale for combined source-channel coding which provides improved quality image reconstruction without sacrificing transmission bandwidth. This approach is shown to result in a relatively robust design which is reasonably insensitive to channel errors and yet provides performance approaching theoretical performance limits. Analytical results are provided for assumed 2-D autoregressive image models, while simulation results are provided for real-world images.
135 citations
Patent•
08 May 1980
TL;DR: In this article, a video inspection system comprising a TV camera for producing a digital video image of a subject, an interface, having a direct memory access channel, for structuring the digital data, a high speed random access memory for storing the data, bus oriented processor for performing high speed processing of the data in the memory, a digital computer for controlling the operation of the system and an operator terminal for communicating with the system.
Abstract: A video inspection system comprising a TV camera for producing a digital video image of a subject, an interface, having a direct memory access channel, for structuring the digital data, a high speed random access memory for storing the digital data, a bus oriented processor for performing high speed processing of the digital data in the memory, a digital computer for controlling the operation of the system and an operator terminal for communicating with the system.
60 citations
TL;DR: In this paper, the authors explore the transformations of a nonstationary image that would yield an image that satisfies the stationary model assumptions and show that algorithms incorporating the stationary assumption produce usable results.
24 citations
Patent•
22 May 1980
TL;DR: In this paper, an improved apparatus and method of pattern recognition and of providing pattern recognition data, which possesses the advantages of optical power spectral analysis and digital image processing, is presented, where an optical read-only memory means such as a photographic transparency is sampled at a plurality of sampling locations with a beam of coherent light.
Abstract: An improved apparatus and method of pattern recognition and of providing pattern recognition data, which possesses the advantages of optical power spectral analysis and digital image processing. An optical read-only memory means such as a photographic transparency is sampled at a plurality of sampling locations with a beam of coherent light. After passage through the transparency, the beam is directed either to a first channel including a transform lens and a wedge-ring detector or to a second channel including an imaging lens and a photodetector array. The improved pattern recognition data is the spatial frequency data provided by the wedge-ring detector and the spatial intensity data provided by the array detector. Hierarchal pattern recognition decisions are made using the two types of data during processing operations to provide improved pattern recognition results.
12 citations
TL;DR: A practical high-speed image information preprocessor using a channel plate image intensifier, which can process optical images, has been developed.
Abstract: A practical high-speed image information preprocessor using a channel plate image intensifier, which can process optical images, has been developed. The preprocessor can perform logical operations such as summation, subtraction, or multiplication of two neighboring frame images on 16 mm film and can also detect moving objects by processing sequential frames. The operation time can be as short as 20 nsec. The image brightness can be as low as about 10-4 1m/m2.
6 citations
Patent•
09 Oct 1980
TL;DR: In this paper, an image synthesiser is provided with several chanels each fed from a detector scanning the incoming video signal, line by line, each channel has a set reference level and stores appropriate light-dark information relative to its reference signal.
Abstract: Where the video image of a test piece is to be compared with stored information about a reference object, good gradation between dark and light is required. For more complicated shapes or structures a single reference level is insufficient to enable compilation of accurate data. An image synthesiser is provided with several chanels each fed from a detector scanning the incoming video signal, line by line. Each channel has a set reference level and stores appropriate light-dark information relative to its reference signal. In this manner, an accurate representation of the test object can be stored and compared with corresponding data from standard. Comparison between test piece and standard can be carried out by a computer. In one arrangement, the TV camera (T) is connected through memory units (Sp, Sp1) with onputs to the n-channels to threshold voltage level detectors (TH1, TH2, -THn) and gate elements (61, 62, 63 - 6n).
3 citations
03 Dec 1980
TL;DR: In this paper, an existing Barnes Engineering, Inc., slow scanning infrared spectral imaging system has been modified to accent an ultraviolet detector, thereby allowing for a two-channel ultra-violet or infrared imagery acquisition system.
Abstract: An existing Barnes Engineering,Inc, slow scanning infrared spectral imaging system has been modified to accent an ultraviolet detector, thereby allowing for a two channel ultra-violet or infrared imagery acquisition system. The infrared optical channel has been al-tered to accept a beam splitter for redirecting ultraviolet scenery and transmitting infrared scenery. The ultraviolet optical channel further incorporates a relay lens, optical filters, and a photomultiplier tube detector. The imagery system controller has been changed to allow for interfacing to several data acquisition systems for increased mission flexibility. In existing data acquisition control system program has been modified to acquire and record data on computer compatible digital tape. Digital image data and synchronizing signals were extended from the original Barnes interface and made available for use by an external digital video real-time display. Existing data editing programs were rewritten to accommodate imagery data, and data reduction programs were written for gray level data reduction. Preliminary ultraviolet and infrared measurements have been conducted with some apparent optical performance and throughput degradations in the ultraviolet channel. References to ultraviolet negative/positive contrasts, atmospheric effects, and system optical performance were analyzed. Video and computer reduced gray scale plots have been acquired, and photographs of video gray scale scenery are presented.
2 citations
Patent•
23 Apr 1980
TL;DR: In this article, the authors propose to record and reproduce digital control signals in a simple constitution by converting them to sine waves different in the number of cycles and recording them on the same track and restoring them to original digital signals after reproducing.
Abstract: PURPOSE:To record and reproduce plural digital control signals in a simple constitution by converting plural digital control signals to sine waves different in the number of cycles and recording them on the same track and restoring them to original digital signals after reproducing CONSTITUTION:Plural digital control signals X, Y and Z are converted to sine waves X', Y' and Z' different in the numner of cycles, and they are recorded on the same track of a magnetic tape This recording is reproduced to restore them to original digital control signals according to reproducing signal width
2 citations
Patent•
17 Oct 1980
TL;DR: In this paper, an image synthesiser is provided with several chanels each fed from a detector scanning the incoming video signal, line by line, each channel has a set reference level and stores appropriate light-dark information relative to its reference signal.
Abstract: Where the video image of a test piece is to be compared with stored information about a reference object, good gradation between dark and light is required. For more complicated shapes or structures a single reference level is insufficient to enable compilation of accurate data. An image synthesiser is provided with several chanels each fed from a detector scanning the incoming video signal, line by line. Each channel has a set reference level and stores appropriate light-dark information relative to its reference signal. In this manner, an accurate representation of the test object can be stored and compared with corresponding data from standard. Comparison between test piece and standard can be carried out by a computer. In one arrangement, the TV camera (T) is connected through memory units (Sp, Sp1) with onputs to the n-channels to threshold voltage level detectors (TH1, TH2, -THn) and gate elements (61, 62, 63 - 6n).
Patent•
21 May 1980
TL;DR: The process allows for the same for processing channels and image processing, as well as for processing signals and image.
Abstract: A.Process STORING DIGITAL SIGNAL COLOR TELEVISION. B.CE PROCESS IS CHARACTERIZED IN THAT INFORMATION IS COMPRESSED AUDIO IN TIME AND THAT THE INFORMATION IS RECORDED VIDEO ALTERNATELY, REAL TIME OR MAY ALSO COMPRESSED TIME. C.The process ALLOWS TO IMPLEMENT THE SAME FOR PROCESSING CHANNEL SIGNALS AND IMAGE.