GB2308259A - Animated parallax display - Google Patents

Description

Animated parallax Display.

This invention relates to animated parallax displays.

Parallax Changing Image displays are well known and typically comprise a grid or lenticulated screen positioned over a multi image print.

There is a special type of animated display known as an animated parallax display which contains two or more integrated images, beneath a lenticular or raster screen. As the display is twisted, or the screen moved relative to the underlay, or the observer moves relative to the line rulings, then different images may become visible. Dependant on the types of images, and the direction of the viewing screen relative to the eyes of the observer, the observer will see either a change of image, or a series of animations, or a three dimensional effect.

The animations effects are, however, generally crude as only a limited number of individual images can be conveniently combined and incorporated, due to the method by which individual frames are traditionally integrated into the final print.

Compared to simple animations, Stereoscopic effects depend upon greater numbers of individual images than for simple animations, with the result that the quality of the stereoscopic effect achieved may be dependant upon the manual effort and mechanical tolerances that are applied to integrating sufficient numbers of film frames, with sufficient accuracy.

According to the present invention, there is provided an integrating camera, which may be an opto mechanical device, or a 'virtual camera' as exists only in a computer which is identical in function to the 'real' integrating camera, by which any number of images can be captured from an electronic display system, and be directly transferred into an animated lenticular image. This image capture is directly from the image being held or displayed, typically as a video sequence, or as a computer sequence, or other digitised or non digitised source, and does without the need for further image manipulation. The 'real' integrating camera comprises an image display screen (typically a cathode ray tube or other monitor), an optical relay system, a continuously travelling, or stepped motion travelling, aperture plate (typically raster barrier grid screen, or lenticular screen) and an image receiving medium (typically film).

The resulting integrated image is then developed/processed, and viewed through a directional viewing screen, referred to hereafter as a 'lenticular' screen, meaning 'acting as a lens', and which may typically comprise a plastic reeded screen, or a raster grid screen, or holographic optical element representing the raster screen. From henceforth in this application, the word 'lenticular' is intended to include all these three types of directional screen.

The traditional methods of combining individual images has been by a stop/start stacato sequence method. This typically involved exposing individual images projected from a filmstrip, onto a recording film emulsion, through a matrix of narrow apertures (typically a lenticular lens or grid). Each image is individally projected, one image after another. Between each exposure, the aperture plate is moved a finite distance.

However, the resulting picture suffers from limitations as to the number of frames, as only relatively few images can be combined because there is a physical limit as to how narrow the apertures can be consistently made, and the accuracy of movement of the film being exposed.

Also, a lenticular screen can only focus a line of finite, substantial thickness, thereby limiting the number of discretely viewable individual frames that may be incorporated.

Also, the stop/start nature of the aperture plate and projected film images limits the smoothness/continuity of the resulting image, and the transfer of images from video to film, if ever attempted, is prone to image jitter and image degradation in the resulting combined image.

Also the use of film as the source of supplying the individual frames, whether projected and then recorded by stocatto or continuous movement of the screen, is extremely prone to give rise to mis alignment jitter due to the need to rely upon sprocket hole registration.

The present invention uses a direct electronic image as input, typically as displayed on a cathode ray tube monitor, or video projector, or electronic display medium, and incorporates a continuously moving, or stepped, aperture plate immediately in front of the recording surface. Alternatively, the recording surface may itself be shifted relative to the aperture plate.

During translation of the moving aperture plate, the shutter is opened in order to expose the recording medium to the virtually continuously displayed image, during which time any number of images or sequences may be continuously displayed from an electronic imaging source.

The resulting image then appears as a continuous excert from a video, rather than the jumpy effect of a flip book. The recording from the monitor directly to the receiving sensitised surface, eliminates the possibility of image alignment error in all directions.

If individual monitor images from a sequence are to isolated, and possibly manipulated, for combining in a preferred sequence, these may be held on the monitor for a finite period of time and the film exposed, during which time the motorised camera back is held static, prior to micro stepping the camera back through a fixed distance before exposure to the next frame. The use of static images on the monitor ensures correct registration between frames, without manual re-alignment.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in which: Figure 1 shows the integrating camera, comprising the image display screen, the camera optics, the travelling aperture plate, and the recording medium.

Referring to the drawing, the integrating unit comprises a image display monitor, or screen, S, a shuttered optical relay or lens L, a travelling aperture plate A comprising either a mask M or lenticular screen L, and an image recording medium, typically film, F, or may be an electronic sensor F.

Figure 2 shows the observer 0 viewing the interlaced image F through the viewing screen V1, which, for special effects, can also be on the opposite side of the image F, at V2., Figure 3 shows the real mask M or lenticular screen L or computer generated 'virtual mask' M, containing clear and black lines, C and B respectively, which is applied to each digitised image in turn, and moved by a distance equivalent, in direction D, to the pitch frequency of the lenticular or raster screen divided by the percentage opening of the aperture.

In the real camera, in order to make the integrated picture, the individual images are captured directly from the those displayed on a video monitor or video projection screen S, typically as a continuous motion sequence. At the same time, between the first and last frame, the aperture plate mask M, or lenticular array A, moves, in a continuous action, a total distance so as to match, or be a whole number multiple of, the pitch of the lines or lens array, of the aperture plate.

To replay the sequence, a grid screen or 'lenticular' screen of appropriately matching frequency, is located, normally in front of the surface of the image, and by moving ones head or by twisting the display, the sequence may be played back.

Alternatively, the screen may be shifted in relation to the surface of the integrated image, in a direction parallel to the run of the lenticles. For real illuminated transparent displays, for special effects, the raster grid or lenticular screen may be positioned behind the image.

The sequence itself may be manipulated before being recorded so as to include special effects such as image enhancement, morphing, slow motion areas, insertion of titles, or sublimimal frames, or removal of specific intermediary frames in order to minimse motion blur effects or errors. Blank frames may also be inserted to emphasise animation effects, and certain key frames repeated to emphasise those frames and increase resolution.

The use of electronic image manipulation allows for 'rotoscope' effects in order to maintain subject position, and size, within a sequence, thereby improving the animation effects.

Low grade images such as those derived from medical scans in particular may be enhanced in contrast and colour to emphasise specific areas of interest.

According to whether the aperture plate A moves parallel to, or at right angles, to the direction of motion displayed on the imaging monitor, 3-D effects may be also included in the animation, but great care must be taken to ensure that any horizontal motion in the scene is not confused with depth parallax information. If stereoscopic effects are required, then the aperture plate A and the lenticular viewing screen needs be placed such that the lenticles, or grid lines, run parallel rather than at right angles, relative to the direction of image rotation, compared to recording a purely two dimensional animation, in which case either direction of travel is permitted.

To enhance and increase the amount of information which may be encoded into the final image, the pitch of the screen through which the master is created, and therefore the size of the master image, may be increased by a factor several times greater than that of the final product, provided replay is through a screen of matching integers.

To help eliminate the moire effect of strobing, and screen clash, caused by interference patterns created between the line frequency, typically between the red/blue/green matrix of the monitor, and the frequency of the scan lines, and the pitch of recording screen, and any subsequent printing screens, either the camera lens, or complete camera back assembly, may itself be traversed during exposure, relative to the film. An alternative method is to electronically oscillate the image being recorded, in a direction relative to the direction of the scan lines.

Claims (16)

1. A 'lenticular' display which is capable of showing animation and, or, three dimensional effects, by recording directly from an electronic monitor or display screen.

2. A 'lenticular' display in which the jumps between individual frames may be no longer recognisable.

3. A 'lenticular' display in which animation, or stereoscopic effects, from film, video, computer graphics, or other display, may be transfered directly to the final film recording medium.

4. A 'lenticular' display within which the speed of motion within the sequence replay may be selectively manipulated so as to create special effects, such as slow motion, within an otherwise consistent speed sequence.

5. A 'lenticular' display in which a sequence consisting of an infinite number of frames may be continously recorded and incorporated, and limited only by the resolution of the film and raster or lenticular screen or display screen resolution.

6. A 'lenticular display' in which the frames within the animation sequence may have been manipulated to give selectively faster or slower animation, even within the same sequence, and in which frames may be 'rotoscoped' in order to maintain subject position and size between adjacent frames.

7. A lenticular display in which certain frames have been eliminated in order to reduce the effect of motion blur, and/or in which certain frames may be repeated to emphasise those frames and thereby enhance clarity.

8. An animation display system in which at least one segment of the images remains fixed in location in space.

9. An integrating camera comprising a video monitor or projection screen onto which the electronic imaging sequence is displayed to be captured.

10. An integrating camera in which a raster grid or lenticular screen, and the photographic emulson or other image receiving surface, are in relative, and continous motion to each other, from the first to the last frame.

11. An integrating camera which will accept sequences in which individual frames may have been manipulated to give special effects such as soft dissolves, 'in-betweening', morphing, subliminal message frames, and other effects.

12. An integrating camera which may use optionally a screen pitch several times coarser than the final viewing screen in order to compress more accurate detail into the reduced size final image.

13. A lenticular display containing directly captured video material thereby eliminating potential vertical and horizontal registration errors.

14. An integrating camera in which the lens and film and film holder may move relative to each other, so as to give an image shift on film to minimise moire effects.

15. An integrating camera in which individual frames may be held static on the display monitor to allow for over-riding the continuous motion, and by allowing the integrating raster or lenticular screen, and the recording surface, to be stepped relative to each other, between exposures.

16. An integrating camera which is a 'virtual camera' in which a computer interlaces the individual images by use of a 'virtual computer mask' which is placed over each frame in turn. From one frame to another, the Virtual mask is moved by a distance equal to the pitch of the screen divided by the percentage opening of the slit and the resulting images overlaid to form the composite interlaced image.