{"id":7044,"title":"Scan Processors","kind":"biblio","url":"https://www.videohistoryproject.org/scan-processors","version":"0d20cc6ff04551d8ccb94a1ba718e96930f3422e6b98331dbe712233be43c4bd","modified":"2026-09-13T21:51:53.8868611+00:00","credits":[{"role":"Author","name":"Sherry Miller Hocking"}],"authorKeys":["Sherry Miller Hocking"],"subjects":["Tool Texts"],"metadata":[{"label":"Publisher","value":"unpublished manuscript","url":null},{"label":"ETC archive","value":"ETC0459","url":null}],"citations":{"page":"\u0022Scan Processors.\u0022 Video History Project, Experimental Television Center, 2026. https://www.videohistoryproject.org/scan-processors.","publication":"Sherry Miller Hocking. Scan Processors. unpublished manuscript. 1978.","risUrl":"https://www.videohistoryproject.org/citation/7044.ris"},"links":[{"label":"Scanned document","url":"https://archive.org/details/ETC0459","relationship":"linked document; contents not retrieved","contentType":"application/pdf"}],"sections":[{"name":"body","source":"VHP record body","generated":false,"characters":35983},{"name":"abstract","source":"recorded publication abstract","generated":false,"characters":91},{"name":"summary","source":"existing VHP generated summary","generated":true,"characters":633},{"name":"archive_summary","source":"existing ETC archive summaries: ETC0459","generated":false,"characters":91}],"content":{"section":"body","source":"VHP record body","generated":false,"text":"\u0022My experimental television is not always interesting but not always uninteresting; like nature, which is beautiful not because it changes beautifully, but simply because it changes.\u0022 -Nam June Paik \u0022The systematic study of scanning in symmetric and asymmetric, geometric and ageometric, deterministic-probabilistic - indeterministic, periodic and aperiodic ways. The main reason for the quick success of my electronic art was that I gave up early the production of video-signals (information quantity: 4 million bits per second), in order to concentrate my efforts on the creation of unusual scanning patterns (very manageable information quantity - 15,000 and 50 bits per second). Especially the addition of third deflection yoke and triple modulation was a breakthrough. The quick switching of various deflection patterns (for example spiral, oval, triangle, etc.) with adequate gate circuits as in chromatron color tv will enrich the variability by far. I am confident that the introduction of the computer to this already well proven area will bring immediate success.\u0022 -Nam June Paik 1966 in Flykingen Bulletin, Stockholm, 1967 \u0022The concept in the Rutt/Etra is that the Rutt/Etra changes the time in which you see parts of the picture. It\uFF92s a machine that manipulates images in time. I see it as a time processor ... I would allocate that feature as Steve\uFF92s and my contribution.\u0022 -Bill Etra, in conversation with Woody Vasulka \u0022I suggest \uFF91Silent TV Station\uFF92, which transmits only beautiful \uFF91mood art\uFF92 in the sense of mood music. What I\uFF92m aiming at with my Lissajous figures and other distortions is a television equivalent of Vivaldi, or electronic Compoz. Lumia art will then became a permanent asset in the collections of millions of people. The \uFF91Silent TV Station\uFF92 will simply be there. Not intruding on other activities, and will be looked at exactly like a landscape or a beautiful bathing nude of Renoir. Normal TV bores you and makes you nervous; this soothes you.\u0022 -Nam June Paik \u0022If on a scale from one to one hundred, the present technology in a given area is zero and the possible technology in that area is one hundred, you should make always a machine that tries to be an eighty or a seventy-five. Then the research and development isn\uFF92t a two year on-going development project that never stops while you\uFF92re building the machine. You design a machine that in possible to build, you spend six months to a year doing it and you bring it out at a reasonable price and it doesn\uFF92t do everything. It doesn\uFF92t do everything that your mind can possibly conceive of, but it does a number of things competently. And you sell it.\u0022 -Greg Leopold, in conversation with Jon Burris Signal processors, a keyer for example, can be defined as image-making devices which alter specific properties of the video signal. In contrast, a scan processor reorganizes images by acting on the systems which control the scanning motion of the electron beam; these devices do not directly change the signal or waveform but rather reorganize the way in which the signal is displayed. The shape and time frame of the electronic signal are the determiners of the appearance of the resulting image as it is displayed on the CRT. In a conventional CRT the deflection systems maintain the horizontal and vertical orientation of the raster, producing a full and stable rectangle of light. Because the signal processor acts on the deflection system, the means of displaying the image, rather than the signal itself, the appearance of the image is changed; the signal which defines the image remains unchanged. With the controls of the signal processor in appropriate positions, the CRT may act as a conventional monitor/receiver and an unprocessed image may be displayed. In general, a scan processor consists of a CRT the normal deflection system of which is modified, a set of controls over the deflection system which alter the raster in specific ways and, finally, a rescan camera. Because the signal defining the image is not changed but only the appearance of the displayed image, the image transformations achieved with the processor must be reproduced optically; scan processors do not output a video signal which can be directly recorded. The reproduction of a scan-processed image is done by the technique of rescan; a video camera is pointed at the signal processor\uFF92s CRT display and the image changes are re-photographed. The rescan camera can then be used as an image source for further processing. The rescan technique results in a degradation of the sharpness of the image; certain scan processors compensate for this by using a high resolution camera or display CRT. Instead of using a standard 525 line scan, high resolution systems employ 945, 1024 or other scan systems. As a technique, rescan does not inherently produce any alterations of the image. The process can be utilized when a pre-recorded tape is used as a signal source in an Image Processing System if no genlock capability is available. Along with genlock, a tape may be simultaneously rescanned to superimpose two different treatments of the same imagery, or to alter the scale of the rescanned imagery relative to the genlocked tape; the change in scale is accomplished by changing the camera\uFF92s position relative to the rescan monitor. For example, the rescanned imagery may be slightly enlarged or reduced or its position shifted. Because the scan lines of the monitor tend to be emphasized, rescan is sometimes used as a design element to achieve textural or linear definition of the image. Rescan has also been used as a means of broadcasting videotapes the signals of which do not permit either direct broadcast or transfer; in this case, the tape is played back on a monitor and the signal from the rescan camera is recorded or broadcast. Scan processors can operate on a variety of image or signal sources. Live camera or pre-recorded information from tape or film, non-optically generated imagery derived from oscillators, and the output video signal from an Image Processing System are all possible sources. Audio signals generated by microphones, radios, audio synthesizers may also be used. Scan processing can be performed on the raster itself, with no image displayed. In general, the types of image transformations possible with a scan processor include shape, position or placement, size, intensity and movement. The raster can be reversed along the XY axis by causing a reversal of the normal scanning operation. Reversal around the vertical dimension transposes right and left creating mirror images, while reversal around the horizontal dimension transposes top to bottom, creating an inversion of the image. Collapse of the raster around the vertical axis produces a single horizontal line while collapse around the horizontal axis produces one vertical line. Simultaneous collapse of both horizontal and vertical create a single, centered dot. Collapse functions are achieved by removing from the horizontal and vertical deflection systems the electrical current which drives them back and forth and up and down. Changes of shape include the banding of the raster or image to conform to the shape of an input waveform. The image can also be moved around the screen or repositioned and rotated in two dimensional and apparent three dimensional space. The Raster Manipulation Unit is a \uFF91prepared television\uFF92, a conventional television receiver which has been electronically modified to permit a wide variety of treatments to be performed on video images; the scan processing is accomplished primarily by the addition of electromagnetic yokes which control the horizontal and vertical deflection systems and by the application of signals to the yokes. The unit is a receiver modified for monitor capability; all of the distortions can thus be performed either on broadcast signals or, when the unit is used as a monitor, on images from live or prerecorded sources. The distortions performed on the image by the unit result from the actions of audio signals on the yokes. Audio signals which are periodic and regular, such as sine or square waves, are normally used when treating a video image; these signals are derived from an audio or function generator or oscillator. However, any audio signal may be employed; these devices include audio synthesizers as well as more conventional components such as audio tape recorders, tuners, microphones or phonographs. These types of signals are most evident visually when used in conjunction with the horizontal or vertical collapse functions which reduce the raster to a horizontal or vertical line. These audio signals cause the line to distort in direct correspondence with changes in the audio signal; often the frequencies present in this type of signal are such that the distortions produced by their actions on a complete image may not be very noticeable. The unit is also capable of reversing the raster around the vertical or horizontal axis, producing images which are reversed left to right or top to bottom in orientation. The raster reversal in combination with audio treatments generate an almost endless series of patterns which are highly controllable. These basic and relatively simple techniques of scan processing were further developed by Korean artist Nam June Paik in collaboration with Hideo Uchida and engineer Shuya Abe during the period 1962-64. Initial experiments involved the placement of external magnet near the CRT; depending on the magnet\uFF92s position, the raster would be deflected in different directions. Paik first exhibited the results of these and other explorations at \uFF91EXPosition of music, Electronic television\uFF92 at Galerie Parnass in Wuppertal, Germany in March of 1963; this is frequently referred to as the first video exhibition in the world. In June of 1964 Paik published an essay in Fluxus Newspaper in which he outlined the \uFF91dimensions of variability\uFF92 of the raster manipulation unit. The first level of variability was the distortion of a broadcast television image which he considered \uFF91the most variable optical and a tidal event of our times\uFF92. The second level involved the modification of certain circuits of the receiver and variations of the horizontal and vertical control systems. The third level was the use of external waveforms derived from audio waveform generators, audio tape or live audio sources; these signals were applied to both deflection systems and the receiver\uFF92s circuitry to create images modulated by the waveforms, with positive and negative areas interchanged. In the January 1965 exhibition \uFF91Electronic TV and Color TV Experiment\uFF92 at the New School for Social Research the vocabulary was enlarged to include raster reversal along the horizontal and vertical dimensions and size reduction of the raster, producing a horizontal or vertical line, and, again, the use of external magnets. In the notes for the exhibition, Paik mentions the experiments of Professor K.O. Goetz of the Kunstakademie in Dusseldorf on the use of the computer to control the CRT, noting that computers, at that time, were too slow to achieve the goal. \uFF91Moonlight Sonata\uFF92 produced by Paik at WGBH-TV in Boston in 1969 for the program \uFF91The Medium is the Medium\uFF92 made use of these prepared televisions to generate abstract form and to distort images of Richard Nixon and other contemporary figures. The impulses for the development of this \uFF91scientifically rather unorthodox\uFF92 method of scan control derived partly from Paik\uFF92s involvement with the Fluxus movement and Happenings, his Eastern sensibilities, an interest in contemporary music, notably that of John Cage, and his own extensive academic background in music. He was also concerned with the notions of variability and the random in the arts and with the humanization of technology, allowing a greater degree of active participation by individuals. Although Paik never attempted the commercial marketing of the unit, documentation was completed by the Experimental Televis","offset":0,"nextOffset":12000,"totalCharacters":35983,"complete":false},"rightsUrl":"https://www.videohistoryproject.org/terms-service"}