CA1107100A - Three-dimensional image production - Google Patents

Abstract

THREE DIMENSIONAL IMAGE PRODUCTION

Abstract of the Disclosure A method of producing on a screen or other viewing medium, a sequence of spaced-viewpoint fixed visual representa-tions of a scene, equivalent to "left-eye" and "right eye" views thereof, so as to produce an image which is perceivable as three-dimensional. The method includes creating alternate or simultan-eous sequential images from each viewpoint. The images are then alternately and recurrently projected onto a screen or otherwise displayed. Projection must take place at a rate of at least fifty-four images per-second in order to be perceived essentially normally as three-dimensional.

Description

Over the years, there has been an increasing interest in presenting visual infoFmation in progressively more realistic lifelike form. For example9 in the field of movie making, after the introduction of black and white silent films, there came synchroni~ed sound9 then color, and then attempts to produce three-dimensional effeets. The latter-mentioned effeets were typically viewable only through the use of special viewer equipment, such as polarized or specially filtered eyeglasses. In the field of television the introduction of black and white television was shortly followed by the introduction of color, and there has been some talk and experimenting in the 10 field of thre~dimensional color television. In still another field--that of fixe~display presentation, sueh as in advertising or home entertainment projections attempts have been made to create a thre~dimensional effect. In advertising, for example, what has been tried is printing under what is known as a lenticular surface. Such printing is capable of producing a slight sensation of depth.
With respect to attempts to introduce three-dimensional effects into the several visual areas generally mentioned above, these have not been especially successful. More particularly, and with respect to motion pictures, the techniques which have been tried heretofore are costly to implement, and are often considered inconvenient by viewers who must wear or use special viewing equipment. Three-20 dimensional television is still in a very formative stage as different concepts are beingexperimented with. Three dimensional fixed displays have not progressed significantly beyond that described above.
A general obje~t of the present invention is to provide a unique, simple, and highly effective method for producing a three-dimensional image~ which method is readily usable in each of the several fields of visual display discussed above.
r Recognizing the fact that visual depth perception, i.e-J three-dimensional peroeption, results from the spacing between the eyes, the present invention rests on the concept of employing in a special manner what might be referred to as "left-eye"
and "~ight-eye" views of a particular scene~ For example, and in the case of motion 30 pictures, camera lenses displaced by about the same distance as the usual human-eye spacing may be employed, with appropriate shuttering techniques9 to place alternate left-eye/right~eye successive images on a strip of film. In the case of television, the . : . . . . ..

sQme basic approach may be used to produce either real-time-available or magnetic-tape-stored electronic data re~lecting such alternat~eye points of view. What has been discovere!d, according to this invention, is that with such alternate eye viewpoints available in projectable or otherwise visually presentable form, an e~tremely striking an~ realistic thre~dimensional image can be created by projecting or pPeSenting these alternate images at a rate no less than fifty~four presentations per second~ andpreferably at some rate exceding this rate.
As will be pointed out below in several specific examples, the method of the invention can simply and effectively be incorporated into the preparation and projection of motion pictures, into the field of television, and also into the field of fixed-display presentation. Other fields o~ use will also become evidentO
These and other objects and advantages which are attained by the invention will become more fully apparent as the description which now follows is read in conjunctlon with the accompanying drawings.
Description of the Drawings Fig. 1 is a simplified fragmentary schematic view illustrating how the method of the invention may be used in conjunction with motion picture film.
Fig. 2 is a schematic diagram illustrating use of the invention in the field of broadca~t television.
Fig. 3 is a simplified schematic drawing illustrating use of the invention with a data-processo~controlled video display.
Fi~ 4 is a schematic showing of use of the invention in the field of ixed-display image projection.
Detailed Description of he Invention The basic concept of the invention is thnt the rapid altern~te presentation to the eyes of views of a scene taken from spaced-apRrt viewpointst typically separated by about the usual distance between a person's eyes, produces a striking and extremely realistic three-dimensional image. More particularly, such successive alternate views must be presented at a rate no less than eifty-four views per second in order satisfactorlly to aohieve this result. Accordingly, the method of the invention includes steps such as the folIowing~ from each of a pair of spaced points ~ view of , a seene deri-ring or producing related scene data; (2) alternately and recurrently using sueh data to produce alternate-viewpoint visible representations thereot; and ;~

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~3) suitably presenting such alternate representations for viewing at a rate no less than fifty four representations per second.
As will be discussed with reference to specific examples below, the step of deriving or producing space~viewpoint scene data of a scene may be done photographically, as for example on motion picture or a projectable slide film, or it may be done electronically, as through the use of a television camera. In case of the use of film, of course, the data is stored as emulsion irnages on the film. In case of electronic equipmentl the data may be directly broadcast without recordin~, or may be recorded on something such as magnetic tape or in something such as the memory bank of a digital computer. The step of alternately and recurrently producing visiblerepresentations of the data, in the case of film, may be accomplished through light-projection through the film, and in case ~ electronic equipment, may be accomplished through the transport of magnetic tape or the calling-out of data from a memory bank.
The step of presenting ~hese representa~ions for viewing at the named rate, in the case of film, may be done through projecting motion picture film onto a screen at thedesired rate, and in the case of still or slide film, projecting alternate viewpoint images onto a screen utilizing a shuttering arrangernent which establishes the desired rate of presentation. With electronic e~uipmerlt, presentation may be made on a conventional video monitor.
Referring now to Fig. 1 in the drawings, indicated generally at 10 therein is a fragmentary length of a conventional motion picture film. According to the invention, alternate space~viewpoint images of a selected scene have been recorded on this film in any suitable manner, as through the use of a camera equipped with a pair of laterally spaced lenses, with appropriate shuttering used whereby successive adjacent image frames on the film alternately receive exposure from the two different lenses. The precise kind of mechanism used to accomplish such e~cposure can take a wide variety of forms all within the capability of those skilled in the art, and forms no part o~ the present invention. Successive adjacent individual image frames are shown on film 10 at 12, 14. Frames like frames 12 are shown with shading~ and rames like 3Q frarnes 14 are shown clear. It will be noted that frames 1? alternate with frames 14.
Shaded frames 12 contain images taken from one point of view, which might typically be the "left-eye" point of view, and clear ~rames 14 contain images taken from the - spaced ~'right-eye" point of view.

According to the invention, it is important that successive alternate viewpoint images be projected or viewed at a rate no less than fifty-four images per second. Acco~dingly, and where motion picture film is used, it is preferred that the s~lccessive alternat~viewpoint images be recorded on the film at an appropriate rate which wiU permit such proje~tion. A specific filming and projection rate which has been found to be highly effective is seventy-two images per second. Accordingly, the successiYe images in frames 12, 14 have been recorded at the rate of seventy-two frames per second.
IUustrated schematically in Fig. 1 as bounded by dash-dot lines 16 is the 10 proiection zone in fl conventional motion picture film projeetor, on one side of which zone is a projec$ion lamp 18, and on the other side of which is suitable lensing and shuttering mechanism 20. The conventional transport or drive mechanism for driving film 10 is shown in block form at 2a, this mechanism being operable to drive the film in a convent;onal manner past and through the projection zone, but at the hi~hly elevated speed of seventy-two Prames per second mentioned above. Shown at 24 in ~ig. 1 is a conventicnal motion picture projection screen onto which images from film 10 are projected.
In operation, and assuming that film 10 has been prepared as described, the film is driven throu~h the prsjection equipment and the elevated speed mentioned 20 whereby, in succession? ~lternate left-eye/right-eye images, or image components, are projected on screen 24. A viewer watehing this screen under these circumstances will observe a three dimensional image~ the depth perception in which depends upon the actual spacing between the two different points of view used in preparing film 10. In the case o~ these points of view being spac0d by about the normal spacing of a person's eyes, a viewer will experience depth perception very closely approximating his normal real-life ~epth perception.
~ nother WAy in which film 10 could be prepared is as follows. Right-eye and left-eye images of a vlew, on ~wo separate synchronized film strips, could be taken simultaneously at, SRy, a ~filming rate of thirty six images per second. Through the use 3d of an optical printer, the like, these images could later be alternately divided or separated, and then meshed onto a single film strip which is then projected at the rate of seventy-two irnages or frames per second. ~ `~

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Fig. 2 illustrates an electronic ~ystem including a video tape playback machine 26 having a video tape 28 ca~ried on transport reels 30, 32. The output of this playback machine is eoupled to conventional video transmitting apparatus represented by block 34 which feeds a broadcastable video signal to antenna 36. At 38 is a conventional ~ideo receiver which receives signals from its antenna 40.
According to the invention~ alternate viewpoint images, similar to those discussed in connection with film 10 above, are suitably recorded on video tape 28.
Such recording can be accomplished in a number of different ways, none of which forms any part of the present invention. For example, a conventional television 10 camera may be equipped with an optical system including a pair ~ later~lly spaced lenses and suitable shuttering equipment for eontrolling the specific times and rates when views are taken alternately through such lenses. In any event, successive aSternate-viewpoint data is recorded on tape 28 at a rate no less than fifty-~our alternate views per second.
It is conventional in television broad~asting today to transmit successive "frames" at the rate of sixty frames per second. Th~ls, and to avold the necessity for modifying this industry-wide standard, alternat~viewpoint views are preferably recorded on tape 28 at the rate of sixty views per second.
To produce ~ three-dimensional image from this recorded inforrllation, 20 playback machine 26 is operated so as to operate the tape at the same speed used during recorciing, and the cons~quence of this is the presentation on the screen in receiver 38 of successive alternate-viewpoint images at the rate of sixty images per second. A viewer watching the screen in the receiver, under these circumstances, will see a thre~dimensional image. Again, the depth perception of this image is directly related to the spacing between the points of view used during r~acording o~ tape 28.
Recent advances in the field of electronics have used digital equipment, such as a digital processor and an associated memory bank, to store vide~displayable information. Such a system can, of course, easily lend itself to use accordmg to the present ;nvention. Thus, and re~erring to ~i~. 3, indicated in block form at 42 is digital 3U equipment including a digital processor 44 and an associated digital memory bank 46.
The output of equipment 42 is shown caupled to a conYentional video monitor 48.
Alternate viewpoint scene data (i.e., left-eye/right-eye scene data) is sui~ably recorded in digi~a~ foPm in memory bank 46. This may be done in any suitable .:
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conventional manner. Further, and where such data is intended to reflect a moving image, appropriate rate information is also recorded isl memory bank 46. To produce a three-dimensional irnage from this data, such alternate viewpoint data is "called out"
of memory bank 46 under the control of processor 44, and fed as video control information to monitor 48. Under this circumstance, a viewer of the scre~n in monitor 48 will obesrve a three-dimensional image. The depth perception perceived by theviewer will again be directly relatable to the point-oI-view spacing, such irlformation also being suitably stored in memory bank 46.
As has been mentioned earlier, the method of the present invention has 10 appli~ability to the field of fixed-display presentation, such as in advertising. Fig. 4 represents in very simplified schematic form a way in which the invention rnay be used for such a purpose. Thus, at 5U, 52 are shown a pair of conventiorlal photographic slides--slide 50 having been taken of a particular scene from what might be thought of as the left-eye point of view, and slide 52 having been taken of the same scer.e from what might be thought of as the right-eye point of view. These two slides are suitably fixed in position, as within the projection zone of a conventional slide projector, and projection lamps 54~ 56 are provided for projecting lighlt through slides 50, S2, respectively. ~uitable focusing lenses are provided for use with the slides. Indicated at 58 in ~ig. 4 is a rotary interference shutter including a radially extending projection 20 slot 58a - disk 58 baing mounted for rotation about Em axiæ 58b. Shown at 60 in Fig. 4 is a conventional projection screen~
In operation, with lamps 54, 56 turned on~ and with the ima~es on slides 50, S2 normally focused on screen 607 dlsk 58 is driven so ns to expose, alternately, the images on slides 50, 52 for projection onto the screen, at the rate of seventy-two images per second. A viewer viewing the screen will pereeisre a three-dimensional image of the scene depicted in the slides.
It will thus be apparent that the method of the invention provides a unique, simple, and extremely effective way of presenting a three dimensional image. It is obviolls that the invention is readily adaptable for use with conventional visual 30 entertainment modes, such as film and television, and that further it has other widespread applicability, such as in the Eield of fixe~display presentatiorl.
While preferred steps of the invention haYe been descrlbed herein specifically, it is recogni~ed that variations and modifications are possible without departing ~rom the spirit of the invention.
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Claims (5)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method of producing a three-dimensional image of a scene comprising from each of a pair of spaced points of view of such scene deriving related scene data, alternately and recurrently producing from such data alternate-viewpoint visible representations thereof, and presenting such representations for viewing at a rate no less than fifty-four representations per second.

2. A method of effecting on a screen or the like a three-dimensional image of a selected scene, said method comprising from each of a pair of spaced points of view of such scene producing scene data representing such point of view, and alternately and recurrently using scene data from such two points of view to effect alternate-viewpoint images on the screen at a rate no less than fifty-four images per second.

3. A method of producing on a screen or the like n sequence of visual events viewable and directly interpretable as a three-dimensional image, said method comprising creating a source of sequentially usable, image-component-effecting, alternate-series data elements, with the individual data elements in each such series representing one point of view of a scene which is displaced by a preselected distance from another point of view represented by the individual data elements in the alternate series, and sequentially utilizing such alternate point-of-view individual data elements from such source to effect sequential image components on the screen, with said utilizing occurring at a rate no less than fifty-four data elements per second.

4. A method of producing from a pair of spaced-viewpoint fixed visual representations of a scene a fixed three-dimensional image thereof, said method comprising alternately and recurrently producing related projectable forms of such two representations, one for each, and projecting such forms for viewing on a screen or the like at a rate no less than fifty-four such projections per second.

5. A method of producing a three dimensional image of a motion-containing scene, the method comprising from each of a pair of spaced points of view of such scene, simultaneously deriving scene data reflecting such point of view, with motion information contained in the data derived from one of these points of view, 7.

except for the fact of spacing between the viewpoints, duplicating that derived from the other point of view, dividing each such derivation of scene data into a series of sequential time separ-able increments, meshing successive increments of one series alternately with those of the other series to produce a composite series of images thereof, and presenting such images for viewing at a rate of at least fifty-four successive increments per second.

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