GB2232292A - Data transfer - Google Patents

Abstract

A method for putting photograph, film or video information as still images, via a digital process, onto a magnetic mastertape that is used for pressing an optical video-disc, which avoids the individual editing of each still image to be done within the transfer process. The still images are captured digitally and either stored on magnetic cartridge as an interim measure before transfer, or fed direct into a solid state video-recorder that is used to put the still images down onto the mastertape in one block, synchronous to the playback speed of the optical video-disc player. In this way "n" different and individual still images put down onto the mastertape in one block, without "n" individual edits, would occupy the correct space on the magnetic mastertape, so as to represent "n" separate images and frames at normal playback speed on the optical video-disc.

Description

DATA TRANSFER This invention relates to the transfer of still images, that are unrelated to one another in content, onto a mastertape for optical videodisc production.

Optical video-discs are used to store still or moving visual images either as separate still images, or as a series of still images that when played at the normal playback frequency of the video-disc system appear to show motion similar in pace to the original motion film or video. Usual playback frequency of still images on our television systems today is twenty-five frames a second. To put down unrelated still images, each of very different visual content, one after the other, onto the mastertape of an optical video-disc has previously meant the expensive process of editing each still image individually and separately onto the final mastertape, usually using an intermediary film or video transfer process, where each still image is individually transferred onto film or magnetic tape prior to a separate edit of each image onto the mastertape.

An object of this invention is to provide a method for transferring separate and individual still images, as distinct from related still images that on playback are a sequence of motion or animation, via a digital process onto a mastertape for production of an optical video-disc, avoiding the editing of each still image independently or one at a time, onto the mastertape, and without loss of quality.

The present method captures still images individually, stores them, and then lays them down onto the mastertape of the optical video-disc "in one block", at the same frame frequency of playback that the optical video-disc delivery system uses. "One block" is defined as a set of images that number more than, for example, 450. This method avoids the editing of each still image individually onto the mastertape for the production of optical discs. In this way, with a playback frequency of 25 frames a second currently used in television systems, 475 frames would be laid down in just 19 seconds, rather than requiring 475 individual and seperate edits or transfers of the 475 unrelated images onto the mastertape of the optical disc. The "in one block" transfer reduces time spent in an editing suite, and thus may save on costs of the image transfer operation.

The process involves converting visual imagery that one can photograph, as still or moving, with a film or video camera, onto magnetic tape, through a digitizing process, whereby information of the images, having been processed by a video camera into video signals, is contained and stored as information on magnetic tape or in the memory system of a computer, and that the information on the magnetic tape or in computer memory is then specifically used as the mastertape for pressing an optical video-disc, that uses a laser beam or laser beams to retrieve information from its pressed surface, where the still images or still components of moving images that are transfered onto the mastertape are frame to frame synchronous in frequency on playback to the operating playback frequency of the optical disc technology used, and where individual editing of each still frame seperately onto mastertape is avoided within the process.

In practising the present method one may use, for example, a video camera, comprising a lens that has a focal length matched to the size and distance from the camera of the still image, motion film or "live action" to be captured, a camera control unit that can be used to manipulate the resultant video signal, a cable that leads the video signal from the camera or from an alternative video source into a digitizing machine that stores the digitized information on magnetic cartridge, tape or in memory, a sync pulse generator that synchronises all the machines used in the process to operate from the same frequency signal that the pulse generator generates, a solid state video recorder that stores up a number of digitized images and then dumps them down onto the mastertape used for the optical video-disc at 25 frames a second or at whatever other standard playback rates are necessary for optical disc operation, cables that may be used optionally to feed the video signal or digitized image into a signal tariffmg desk to allow further manipulation of the video signal before it it is digitally captured or to allow manipulation of the digital image once captured or stored, and cables that optionally allow one to bypass the digitizing machine and feed the initial video signal from the camera into the solid state video-recorder itself for dumping directly onto the master magnetic tape at the relevent speed to be synchronous with the playback frequency of the optical video-disc.

A specific use of the method will now be described by way of example with reference to the accompanying drawing which shows in perspective, the full array of component items used to process sets of 35mm film transparency still photographs onto mastertape for optical video-disc production, without any individual editing of each image and without possible subsequent generation of loss of image quality, where the digital image is permanently stored before being downloaded onto mastertape.

35 mm transparencies 4 are illuminated by a slide box 1 in front of which a single transparency 3 is mounted at any one time in the slide mount 2 affixed to the slide box 1.

In the case of 35mm transparencies a sharp 50mm distagon lens 5, or other suitable lens, is affixed to the front of a suitable video camera 6, that for best results can output its signal as RGB as well as composite video signals, in this example using a Sony BVP 7 CCD chip video camera. Cables 7 transport the RGB or composite signals to a camera control unit 8, where the camera control signal may be manipulated with reference to a viewing monitor and / or an oscilloscope 9.

Further cables 10 lead the video signal, optionally manipulated using the camera control unit 8, into the RGB or composite input of a digitizing machine 11, in this example "SlideFile" by Rank Cintel Ltd. Capturing of images by the digitizing machine is manually activated each time a transparency from the set 4 is placed onto the slide mount 2.

The digitizing machine 11 is optionally used to store images on magnetic cartridge 12 with reference to a viewing monitor 13 to check results.

The interim storage of digital information on magnetic cartridge does allow the possibility of other video effects to be applied to the digital information therein stored.

If storage of information on cartridge is desired, then playback of cartridge 12 on a similar digitising machine 14 to the previous one used, or on the digitising machine 11 if using the same machine at a different time or in a different location, allows the same digitised image of the camera control unit 8 output, without any noticeable loss in information quality, to be relayed through cables 15 into the RGB or composite inputs of an SSVR 16 (Solid State Video Recorder), in this example one produced by Quiztec Ltd. The output from the SSVR 16 is taken via cables 17 to a suitable magnetic tape machine 18 that is used for mastering optical video-discs. In this example and at the present time, 1" broadcast video-tape is used as the mastertape format.

Where two or more machines are linked simultaneously, a sync pulse generator 19 is used to genlock all the machines to the same pulse; a necessary procedure with all video production today.

The tariff and colour correction desk 20 may be linked into this chain either between the camera control unit 8 and the digitizing machine 12, or between the digitizing machine 14 or 12 and the SSVR 16, or between the SSVR 16 and the video-tape machine 18.

To bypass the facility of using a digitizing machine 11 or 14 to store a permanent record of the digitized images as a back-up copy or for further manipulation by other means, cables 10 from the camera control unit 8 are fed into the RGB or composite video inputs, as relevant, of the SSVR 16 and thence onto the magnetic mastertape used for mastering the optical disc. In present circumstances the mastering is done on a 1" broadcast video-tape machine 18, but the SSVR output may be stored digitally or non-digitally on other visual or non-visual magnetic format, from which the optical video-disc is pressed.

Claims (10)

1. A method that transfers still visual images from their original medium onto magnetic mastertape for the production of optical laser disc, wherein unrelated still images are laid down onto the mastertape at the same frame frequency as the operating playback frequency of the optical disc technology used, and the individual editing of each still frame seperately onto the mastertape is avoided.

2. A method as claimed in Claim 1 wherein still or moving film or video imagery is transferred from the form of individual transparency or negative film photographs, with a light shone behind them, via a digitising process into digital storage before the digitised images are transferred at the disc frame frequency onto magnetic tape, for the pressing of an optical disc.

3. A method as claimed in Claim 1 wherein still or moving imagery is transferred straight from a celluloid or video-tape medium into digital information, contained on magnetic tape or in computer memory, that can be manipulated and colour tariffed before being downloaded onto the mastertape for the optical video-disc.

4. A method as claimed in claim 1 wherein still or moving imagery is transferred from a celluloid or video-tape medium or as "live" images into digital information that is stored on magnetic tape, as an interim measure, before the magnetic tape is to be loaded at a later date for manipulation and / or addition and subsequently for downloading onto the magnetic mastertape for the pressing of an optical video-disc.

5. A method that incorporates all the features expressed in claims one to four.

6. A method of recording still images on optical disc, comprising digitising a multiplicity of individual still images, recording the digitised still images on magnetic tape at the optical disc frame frquency, and transfering the images from the tape to an optical disc.

7. A method of making a magnetic master tape for production of an optical disc, comprising digitising a multiplicity of individual still images, and recording the digitised still images onto magnetic tape at optical disc frame frequency.

8. A method as claimed in claim 6 or 7 comprising storing the digitised images before recording them on the magnetic tape as a block.

9. A method as claimed in claim 8 further comprising manipulating the stored digitised images.

10. A method of making a magnetic master tape, substantially as described with reference to the drawing.