JP2009510489A - Method and apparatus for optimizing the viewing distance of a lenticular stereogram - Google Patents

Abstract

  Method and apparatus for optimizing the viewing distance of a stereogram system. In the stereogram, the image (102) is kept in close contact with the lenticular screen (101). In the present invention, the optimum pitch value corresponding to the designated viewing distance is stored using a data storage device. Thereafter, an alternating fitting program is applied to the table values to perform mapping of the alternating fitting visual images corresponding to the respective viewing distances. Here, the user can select or designate a desired viewing distance, and the optimum mapping of the viewing image is automatically selected and displayed.

Description

  The present invention relates to three-dimensional stereoscopic print images, also known as lenticular stereograms or parallax panoramagrams, and more particularly to a method and apparatus for enlarging the viewing zone of an image in a lenticular stereogram.

  Lenticular stereograms have been in use for many years and are truly stereoscopic without the need for the viewer to wear a special selection device that selectively displays different images to the left and right eyes. An image is displayed. The selection device is usually glasses, which are colored (red / green) or polarized so that the left and right images can be seen from one information source. Lenticular stereograms are produced by photolithographic copying and are most commonly used for trading cards, picture cards, product displays, and the like. By incorporating a cylindrical lenticular screen with a corduroy-like surface over the entire surface of a properly encoded image print, a three-dimensional depth effect can be obtained.

  As shown in FIG. 1A, the lenticule 101 has a semi-cylindrical surface positioned so that the lengths in the vertical direction coincide with each other. The lenticules are juxtaposed with a printed image 102 that includes a sequence of encoded visual information. Each column of the print image 102 is associated with a specific lenticule, and each column has a series of visual images from the left end layout to the right end layout. Therefore, instead of viewing a single image as in a normal print, the panoramagram observer will see multiple projected images in both the left and right eyes due to the refractive properties of the panoramic lenticular surface. Become. Specifically, since the left eye sees the lenticular stereogram at a different angle from the right eye, each eye captures a different image from the image and generates a three-dimensional image.

  While the technology for making lenticular stereograms continues to advance, some problems still remain, preventing further spread of this medium. In particular, in the lenticular stereogram, the range in which the lenticular stereogram can be viewed without causing the three-dimensional image to collapse due to the parallax effect is limited. In order to properly view the entire print or display, the columnar image and all associated cylindrical lenticules must be closely juxtaposed. The center of the image is usually seen at an angle close to vertical, but the left and right edges of the image will be seen at a fairly acute angle. At acute viewing angles, a parallax effect occurs, losing accurate juxtaposition between the columnar image and the corresponding cylindrical lenticule. The loss of juxtaposition occurs because at very acute angles, the focus of the lenticule is not properly positioned on the associated print row and an inaccurate cylindrical image is visible.

  The range of points at which a complete and accurate three-dimensional lenticular stereogram image can be viewed is known as the “view zone”. In the prior art, attempts have been made to maximize the viewing zone by suppressing the parallax effect. For example, US Pat. No. 5,838,494 discloses a mathematical technique for optimizing the viewing zone by adjusting the width of the print row to match the width of the lenticular screen, With this technique, a screen with accurate lenticule width dimensions must be obtained. U.S. Pat. No. 5,083,199 requires an air gap that improves the viewing zone of the lenticular stereogram, and it is uncertain whether paper prints will work in this manner. In addition, the lenticular screen is assembled on a curved structure having various lenticule widths, but it is extremely difficult to manufacture such a structure. Corresponding to a paper titled “Technical Info on PHSColors (R)” by E. Sandor et al. (See http://www.artn.nwu.edu) Although it is disclosed that the viewing area of the lenticular stereogram is enlarged by using a print line wider than the width of the lenticule, a method for adjusting the width of the print and the width of the lenticule is not described. Thus, none of these documents provide a simple solution to maximize the viewing zone of the lenticular stereogram.

US Pat. No. 5,838,494 US Pat. No. 5,083,199 International Publication No. WO 98/27456 Specification US Pat. No. 3,409,351 Article titled “Technical Information on PHSColorgrams® (Technical Info on PHSColorgrams®)”, E. Sandor et al. (See http://www.artn.nwu.edu)

  The present invention has been made to provide a simple method for enlarging the viewing zone of a lenticular stereogram.

  The present invention provides a simple method for enlarging the viewing area of a stereoscopic image, which may be a photographic print, a projection or a computer generated image, or any other type of graphic image. . The viewing zone is improved by setting an optimum row width for the image row of the stereoscopic image. The optimum column width provides an optical arrangement of each column and its corresponding lenticule for a given viewing position. The optimal column width may be determined experimentally using a series of test images. After the determination, a stereoscopic image having an optimum row width can be generated using an interdigitation program.

  Each test image has a plurality of columns, each column corresponding to a single lenticule of the lenticular screen. Each column has two single color stripes, each of which is distinguishable or visually distinct from each other. Therefore, the colored stripe alternates across the entire width of the test image.

  The optimum column width is determined by viewing the test image and the lenticular screen with a viewing device having a left eye viewing position and a right eye viewing position. If the image looks like one color when viewed from the left eye viewing position and looks like the other color when viewed from the right eye viewing position, the optimum column width is achieved. The test image with the optimum column width can be determined by looking at a series of test images with different column widths. A stereoscopic image can then be generated using the optimal column width, and the viewing zone is maximized when the central column of the stereoscopic image is aligned with the central lenticule of the lenticular screen.

  In the present disclosure, a method for optimizing the viewing distance from the display instead of optimizing the angle range of the viewing zone will be described.

  Referring to FIG. 1A, a portion of a lenticular screen 101 and associated print 102 is shown. The term “print” is used in a broad sense, and in addition to known displays such as rear projection displays, photographic prints, prints reproduced in photolithography, electronic display screens, etc. Means a combination of The print 102 is in intimate juxtaposition with the lenticular screen 101 to form two parallel planes, such that the plane of the print 102 is defined by the point ADLI and the lenticular reference plane is defined by the point EHPM. Fixed to. The lenticules are individual cylindrical lenses EFNM, FGON, and GHPO, each having an equal radius arc EF, FG, and GH, and cylindrical surfaces illustrated as their corresponding arcs MN, NO, and OP. The lenticule screen is superimposed on the top of the reference plane EHPM, and each lenticule is optically arranged in close juxtaposition with a corresponding rectangular print area on the print 102 to provide different images or images from different viewing angles. Provide a visual image. For example, the print area ABJI is closely juxtaposed just behind the lenticule EFNM.

  Referring to FIG. 1B, a more detailed view of the print area ABJI and the corresponding lenticule EFNM is shown. Five columns or stripes 1, 2, 3, 4, and 5 are inherent in the print area 102. Any number of columns can be used, but only five columns are shown for clarity. Due to the optical properties of lenticules, only one stripe is visible from any one viewing position. The stripe 1 includes the rightmost visual image, and the stripes 2, 3, 4, and 5 appear in order as the viewpoint moves from right to left.

  The production of this type of interdigitated stereogram print is well understood. In the illustrated five rows of stereograms, five projected visual images are generated by five cameras that are arranged at an equal distance from each other facing straight forward and simultaneously taking pictures. These images may be taken digitally or taken by conventional photographic means and then scanned digitally. These digital images are then clipped using an interdigitation software algorithm and assembled as a new stereogram print. Stereogram prints interfit the views of individual projected images (sometimes mistakenly referred to as “interleaved”) to create a print area corresponding to a particular lenticule into several discrete images. It is manufactured by composing with a stripe. When viewing a lenticular stereogram consisting of five interdigitated images, viewing the lenticular stereogram in five different angular ranges gives you a view of five different images.

  Interdigitation algorithms and software are well known in the art. An exemplary interdigitation algorithm is described in detail in WO 98/27456, which is incorporated herein by reference.

  FIG. 3A illustrates the parallax problem. The lenticular print is shown in the area of the brace symbol 301A. For simplicity, only three representative lenticules 303, 305, and 307 and their corresponding print areas 309A, 310A, and 311A are shown. As described above, any number of lenticules and rows can be utilized. The observation point 302 is located directly above the central lenticule 305 and in the center together with the on-axis image of the lenticular print. (The vertical line drawn from the observation point 302 intersects the print and the horizontal center of the lenticule 305.) The light beam observed at the observation point 302 is refracted by the lenticules 303, 305, and 307. Are focused at 304, 306, and 308, respectively. The parallax problem in this example is caused by focal points 304 and 308 that do not match the corresponding print area. In FIG. 3A, the focal points 304 and 308 are completely out of print areas 309A and 311A, and are thus completely invisible from the observation point 302. Therefore, only the printed image near the central area 310A only looks three-dimensional.

  The images on both sides of the center of the print appear to be distorted or confused, but this means that the column that will enter the eye and its corresponding stripe part does not correspond to the proper stereoscopic image Because. In such a situation, the eye is likely to see the left image with the right eye and the right image with the left eye. Therefore, if the correct correction movement of the print row with respect to the lenticule is not performed, the range of viewing angles within the viewing zone is significantly narrowed.

  The parallax problem diminishes as the distance between the observation point 302 and the print increases. This will be described with reference to FIG. 3B. If the observation point (not shown) is far away from the print, the rays from the lenticule to the observation point become more parallel, so that the focal points 304, 306, 308 are printed areas 309B, 310B, Fits in 311B. At this observation point, there is no parallax problem at the end of the print, so there is no need to move the print areas 309B and 311B. Therefore, to avoid parallax problems, for narrow prints, a wider lenticule screen should be viewed from a greater distance to suppress the acute viewing angles on the left and right sides of the print. I must.

  In order for the entire stereoscopic image to be visible, the focus of the lenticules must all fall within the boundaries of the print area corresponding to each lenticule. FIG. 3C illustrates one embodiment of a lenticular stereogram. In the present embodiment, the print area is moved in the horizontal direction so that the focal points of all the lenticules fall within the corresponding print areas. This shifted print area eliminates the parallax problem and allows the complete image to be viewed from an observation point where the rays between the observation point and the lenticule are not parallel. The parallax problem is corrected by moving the print areas 309C and 311C horizontally relative to the lenticules 303 and 307 so that the focal points 304 and 308 are incident on the center of the print areas 309C and 311C, respectively. . The print area 310C does not need to move because the focal point 306 is already incident near the center of the print area 310C.

  In general, to project a complete stereoscopic image, move the print column on the left side of the print to the left, and then move the print column on the right side of the print to the right so that each lenticule is above the appropriate print area column. To focus on. The distance that each row moves horizontally is a function of the angle at which each print row is observed and is inversely proportional to the distance between the viewpoint and the lenticular screen. The amount of movement of the print area row increases as the observation point approaches the lenticular screen.

  The technique of the present invention that maximizes the viewing area of the lenticular stereogram utilizes the lenticular screen as a calibration and measurement tool to determine the optimal print column width for a particular viewing distance. FIG. 1C shows an embodiment of the invention having a lenticule 106 and a corresponding print area 105 composed of two stripes 103 and 104. In the technique of the present invention, these two stripes are composed of complementary colors or contrast colors. For example, the stripes 103 and 104 may be white and black, magenta and cyan, green and red, or other identifiable colors, respectively. Prints of full-size stereoscopic images with correct column widths and contrasting colors may be created using an interdigitated computer program. Thus, a series of two-color test prints can be formed to have different image row widths that increase step by step. Image prints can be generated with row width accuracy of 0.01 inches or more.

  A two-color test print is used with a stereogram image viewing device to determine the optimum image print sequence width for a particular viewing position. The lenticular stereogram image print generated using the optimal print row width has the perfect three-dimensional appearance in addition to full visibility. Since a single image print row width cannot be optimally viewed from all positions, the image print row width is designed for a specific viewing distance. In general, the lenticular stereogram is designed to be viewed from a central position, but the distance at which the lenticular stereogram is visible is variable.

  Using a device that visually recognizes a stereogram image, a two-color test print can be viewed from a specific viewing position. An embodiment of a stereogram image viewing device is shown in FIG. This visual recognition device includes a positioning device 201 having peep holes 202 and 203, a support column 204, and a base board 205. The support column 204 holds the positioning device 201 in a fixed manner above the base board 205. The lenticular screen 206 is juxtaposed with the print 207 so that the central lenticule is directly above the central print row. The aligned print 207 and the lenticule screen 206 are placed directly below the viewing device 201 so that the lenticule is positioned vertically with respect to the inspector, and the center of the print 207 is positioned between the viewing holes 202 and 203. It arrange | positions so that it may be located under the midpoint 208. FIG. The inspector observes the print 207 from the peep holes 202 and 203. In an alternative embodiment, a digital camera is placed and the print 207 is displayed as viewed from the peepholes 202 and 203.

  If the width of the print row is optimal and the focus of the lenticule is on the appropriate row of the print area (as described in FIG. 3C), the image 207 appears to be a uniform color from the peephole 202; The uniform complementary color or contrast color appears from the peephole 203. Defects in the test print or lenticular screen may cause some defects in the viewed image. Test prints with an inappropriate print row width do not appear to be uniform colors. By observing a series of test prints having different column widths of the printed image with a stereogram viewing device, a print having the most uniform color observed from the observation holes 202 and 203 can be quickly identified. The best row width dimension corresponding to this test print is input to the interdigitation program to generate a stereoscopic image print having an optimum image row width and an optimized viewing zone.

  Observation of prints through a stereogram image viewing device and a lenticular screen is a high-precision measurement tool that allows rapid determination of the optimum print image sequence width. In this technical field, the term pitch is often used to describe the column width or lenticule width of a print. The pitch is the number of rows per inch or the number of lenticules. When the print / lenticule screen combination is viewed from a considerable distance, the pitch of the print row and the lenticule is equal. In another example, at a viewing distance of 3 feet, a lenticule screen with a reference pitch of 58.23 is the maximum when used for prints with a pitch of 58.35, ie 58.35 rows per inch. Give birth to the viewing area. Also, a 3D print optimized for a viewing distance of 3 feet provides excellent 3D image formation even from a viewing distance of about 2-5 feet.

  There are many variations on the basic technique of the present invention. The techniques of the present invention can be used to calibrate or align moving images, electronic images, and lenticular screens utilized in combinations of electronic and known display devices, as well as rear projection slide films. In particular, a computer may be implemented with a lenticular screen and an interdigitation program that allows a test image to be projected to determine the optimal viewing zone for a particular user. In this case, the computer displays a stereoscopic image having an optimum column width magnification in optical alignment with the lenticular screen. The alignment of the projected image with the lenticular screen may be performed by display control or software.

  In other embodiments, a series of print patterns with different column widths is provided. This print pattern may be viewed from a single position by a single eye. An appropriate series of test patterns with different column dimensions can be utilized to experimentally calibrate the optimal width and position of the image print column relative to the lenticule to optimize the viewing zone.

  In other embodiments, a two-color test print may be combined with an image print for alignment. Referring to FIG. 4, a print 401 having a two-color border pattern in regions 403, 404, and 405 and a picture region 402 are aligned with the lenticular screen using the above-described alignment method. Thus, the viewing zone can be arranged in the center and not tilted to the left or right. The lenticular screen is disposed on the print 401, and the print 401 is visually recognized via a stereogram visual recognition device. Here, the two-color border pattern is aligned with the lenticular screen when the border appears to be one color when viewed with the right eye and the contrast appears when viewed with the left eye. Centered.

  This will be described with reference to FIG. In other embodiments, a first two-color pattern may be used for the horizontal border region 405, and another type of second two-color pattern may be used for the vertical border regions 403 and 404. Good. For example, stripes with alternating black and white may be used for the columns of vertical regions 403 and 404, and stripes with alternating red and green may be used for the horizontal region 405. The black and white stripes in the regions 403 and 404 can be used to align the lenticule in the rotational direction with respect to the print row inserted therebetween. When viewing the print through the imaging device, one eye observes the vertical border areas 403 and 404 as black and the other eye observes the vertical border areas 403 and 404 as white. become. The red and green stripes in the region 405 can be used for centering the inserted print and the lenticular screen by placing two color columns in the center of the print 401. Again, one eye will recognize the region 405 as green and the other eye will recognize the region 405 as red.

  Yet another embodiment is shown in FIGS. 5A and 5B. This embodiment includes means for changing the optimal viewing distance of an autostereoscopic display. This is advantageous when the content creator or user can set the display to a specific distance or a specific distance range. In particular, a user may want to see the display from a desktop viewing distance at a certain moment, or may want to show the display to a group of people from a greater distance, for example.

  Game consoles at game centers are an example of why it is required to have the flexibility to change the viewing distance. The game machine has two modes, a demo mode and a play mode. In the demo mode, the viewing distance needs to be set farther, and in the play mode, the viewing distance needs to be set closer.

  Also, because the lens screen has refractive properties in the horizontal dimension rather than the vertical dimension, the angular range of the viewing zone may be constant no matter where the user is located above or below the screen. Take note. There is an exception to this, and in the case of using the Winnek formula disclosed in US Pat. No. 3,409,351, there is a vertical component in refraction, so that the user moves in the vertical direction. Viewing zone movement will occur. Next, a method for optimizing the appearance of an autostereoscopic image within a viewer's viewing area at a predetermined distance will be described.

  Referring to FIG. 5A and FIG. 5B, image regions with reference numerals 1, 2, 3, 4, and 5 correspond to stripes indicated with reference numerals 1, 2, 3, 4, and 5 in FIG. 1B. To do. Each stripe is refracted by lenticule 101, one of a continuous collection of lenticules, to form a viewing zone. Each viewing zone consists of individual projected views indicated by reference numerals 1, 2, 3, 4, and 5. Referring to FIG. 5A, a display screen 501, a near observer 503, a viewing zone 507, and a distant observer 505 are shown. The observer's eyes are provided with reference signs L (left eye) and R (right eye). Referring to FIG. 5B, a display 502 is shown with near and far observers 504 and 506, respectively, with the left and right eyes of the observer being labeled with L and R, respectively. The viewing zone is indicated by reference numeral 508.

  5A and 5B are schematic representations and are made for illustration purposes. These figures are exaggerated and simplified, but accurately depict the concept. The viewing zone angle is much narrower in FIG. 5A than in FIG. 5B, but this angle can be controlled by the geometric relationship between the stripe and the lenticule.

  By controlling the angle of the viewing zone from the viewpoint of the viewing zone arrangement using the above-described means, it is possible to bring about an optimum effect for a situation called a parallax condition. This means that the columnar structure image elements and the associated cylindrical lenticules must be aligned. As described above, the center of the projected image is usually observed at a substantially vertical viewing angle, and in this case, the columns at the left and right image edges are viewed at an acute angle. The parallax effect occurs at such an acute viewing angle, and as described above, accurate juxtaposition between the columnar image elements or stripes and the associated cylindrical lenticules is lost.

  By utilizing the same means as the techniques already described, the angular range of the viewing zone can be optimized over a specific range to obtain the best results that can be achieved for a specific viewing distance.

  The present disclosure also describes a conventional lenticular array in which the lenticule boundaries (ie where the individual lenticules intersect) are provided in the vertical direction (ie, parallel to the vertical edges of the lens sheet or display). Although described with respect to a display having a note, it should be noted that what is disclosed herein functions similarly in situations using obliquely oriented lenticular sheets as disclosed by Winneck.

  The range of the viewing zone can be controlled by the means described above, and the motivation for changing the viewing angle is exaggerated as pointed out in FIG. 5A as compared to FIG. 5B. However, it is properly explained. For position 503, it can be seen that the left and right eyes are outside the viewing zone. That is, an observer in the vicinity will see an image in an inappropriate state with the left eye and the right eye, which means that the stripe (1, 2, 3, 4, 5) This is because it does not spread in a fan shape that generates an optimized field of view. However, as can be seen from the figure, the eye is located outside the advancing range of the stripes (projected images 1 to 5) in the zone, so that the observer can use a pseudoscopic zone instead of a three-dimensional zone. You can see for sure.

  At 505, an observer at a greater distance is viewing image stripes 2 and 4 that produce a sufficient stereo effect, as shown. What can be done for a user located at a closer distance 503 here?

  Referring to FIG. 5B, the observer is here indicated by the reference numeral 504 at the same distance from the display 502, which corresponds to the distance of the observer 503 from the display 501 in FIG. 5A. It can be seen that the left and right eyes of the observer are well within the viewing zone and a stereoscopic image is observed. Here, in FIG. 5B, attention is paid to an observer located at a further distance 506. This observer corresponds to the observer 505 in FIG. 5A. In this figure, the left and right eyes of this observer are within a single projected view, so that the viewing zone angle becomes too large at this observer's distance, and there is no stereoscopic effect. Therefore, a three-dimensional effect cannot be obtained at a distant distance having a wide viewing area. Similarly, for example, when the left eye of the observer sees the projection visual image 3 and the right eye sees the projection visual image 4, the observer views the visual image 2 with the left eye and the right eye, for example. As long as the image 4 is viewed, an effective axial separation as large as that seen is not obtained, and the above-mentioned motion is generated.

  As can be seen from the drawing, observers at different distances can be absorbed by changing the range of the viewing zone or the angle of the viewing zone. In one example, for example, in FIG. 5A, there is no stereo effect when the observer is at position 503, whereas the stereo effect at the distance represented by the observer at 505 is good. On the other hand, in order to correct this situation, the distance between either the columns or the stripes is changed here to form a substantially wider viewing zone. All of this is accomplished by utilizing software adjustments through an interpolation process that replicates or thins out pixels within or between image stripes to control either the distance between columns or the distance between stripes.

  Thus, using a software procedure and changing the appropriate distance in a manner similar to that described in the present disclosure in the context of viewing zone optimization for the lens sheet, the viewing zone as a function of the viewer's distance Can be optimized.

  Such a distance can be set in the software, and a predetermined lenticular display can be optimized according to various viewing distances. It will be understood that the optimum distance is within a certain range. For example, setting the display to an optimal distance of 3 feet provides adequate viewing conditions up to about 2 to 5 feet, and by setting the display to an optimal viewing distance of 8 feet, the viewer is about 6 to 15 feet And can be seen effectively. Therefore, we are not talking about absolute values in some situations, but about value ranges.

  By utilizing observer distance measurements, a means for automatically changing the aforementioned optimization can also be provided. The auto-ranging process takes this distance measurement, so that the display automatically adjusts itself using the modification process described here, depending on the distance from the display screen to the viewer. The effect can be optimized.

  There are many types of range characterization devices described in the literature, and these devices are actually employed in a variety of products. The problem is to select the least expensive equipment technology that corresponds to the desired performance, but in this case only a relatively low accuracy is needed to achieve a satisfactory effect, so that The manufacture of the system can be realized using low-priced products. In addition to sonar and radar, various technologies such as those used in general consumer cameras can be adopted. Viewing distance can also be optimized for a set of observers using simple logic and an averaging process.

  Referring to FIG. 6, an autostereoscopic display 601 is shown for use with the device 604, which is any type of range identification device that measures the distance of the observer 603.

  Next, the actual software embodiment employed to execute the optimization procedure described herein will be described in detail.

  Software interdigitation calculations for autostereoscopic displays are disclosed in US Patent Publication No. 2001011969, entitled “Autostereoscopic Pixel Arrangement Techniques,” which is incorporated herein by reference. Incorporated as part of

  As shown in FIG. 7, this logic assumes that a finite number of equal stereo views (701-709) need to be interdigitated into the display (710). The process of acquiring these stereo views varies from computer generation to photography. These stereo views can be stored in computer files or processed interactively. When input to the software interdigitation process, the view is represented in a raster format, and each color pixel (711) in the view's raster grid is a sub-pixel of red 712, green 713, and blue 714. Defined. Similarly, display 710 is a physical raster display with color pixels 715, which are actually a set of subpixels consisting of red 716, green 717, and blue 718. Since these subpixels may have a gap between the subpixels, they do not completely fill the pixel area, but do not affect the following calculation.

  The size of the stereo images 701-709 relative to the size of the screen 710 does not affect this calculation. In the preferred embodiment, there are nine stereo views of equal size and the display size is equal to three times the horizontal size of the stereo view and three times the vertical size of the stereo view. Since the interdigitation process does not change the aspect ratio of the stereo view, it is assumed that the aspect ratio of the stereo view matches the aspect ratio of the display.

  The software interdigitation process determines the mapping of the subpixel from the subpixel of the stereo view to the display surface. Within every display pixel, there is a mapping of the red, green and blue sub-pixels. As an example, for the first display pixel 715, the mapping (719 red, 720 green, 721 blue) of the subpixels (716, 717, 718) is the subpixel (702, 706, 709) in the stereo view (702, 706, 709), respectively. 722, 723, 724).

  The physical width of the subpixel on the monitor can also be measured so that the physical width of the lenticule can be measured. A common measurement that correlates these is to determine the pixel to lenticule pitch ratio. FIG. 8 shows a series of lenticules 802 located above a pixel column 801 in the display. The pitch 803 is the number of pixels covered by a single lenticule. This number need not be an integer.

  By determining this pitch ratio, the geometric relationship between the lenticule and the RGB sub-pixels of the display located under the lenticule can be simply described.

  As shown in FIG. 9, the lenticule 901 provided on the pixel row 902 of the display is divided into a plurality of equal sections corresponding to each stereo view image. Each subpixel 912 in the pixel column of the display is examined one by one to calculate the center location 913 of the subpixel. Next, a specific visual image is selected for the sub-pixel according to the position of the lenticular section. When there are V views, the view V is selected if the center position falls within the first section, the view 1 is selected if the center position falls within the last section, and so on. The

  After the view is determined, the next step is to identify the color values to use for the display subpixels. The color value to be used is determined by selecting sub-pixels of the same color (RGB) in the stereo image selected at the same position (width, height) as the display pixels.

  There are several variations on this logic, including performing a weighting approach that considers all of the lenticule sections in which the subpixels are located. It is also necessary to consider the lenticule tilt relative to the raster display. However, for the purpose of describing the present invention relating to viewing distance, these detailed improvements need not be considered.

  The test program is used to generate an interfitted view image. The predetermined number of visual images are defined using contrast colors (red / green, black / white, etc.). In one standard embodiment, nine views are defined using the first four reds, the middle one black, and the last four greens. The operator enters the value used for the ratio of the lenticule pitch to pixel to specify the width and height dimensions of the display. The resulting interdigitation pattern is then calculated and displayed on the display. When properly viewed at a known distance, the operator will see red with the left eye and green with the right eye.

  By using such a test program and viewing the resulting pattern at various distances, the operator can experimentally determine the optimum pitch value at each desired viewing distance. This process involves iterating over pitch values until the viewed pattern appears to be completely red in one eye and completely green in the other eye at the desired viewing position. Upon completion, a pitch table is generated that includes the viewing distance and the lenticule pitch. The pitch value and the viewing distance are not necessarily in a proportional relationship.

  The number of entries in the table is arbitrary. Several strategies can be used when building a table. The first is to obtain a predetermined distance corresponding to all monitors. For example, if two fixed viewing distances (eg, 3 feet and 15 feet) are considered sufficient for all viewing situations. The second is to obtain a series of continuous viewing distances. In this case, it is necessary to set the pitch for as many viewing distances as possible. The third is to obtain a qualitative distance (for example, near, middle, far) representing a range in which the physical distance between monitor models can be changed.

  Once the pitch table is defined using the test program described above, the next goal is to apply the table information to the interdigitation viewing program. Such a program (a program as described in the above-mentioned US Patent Publication No. 20020011969) performs the interdigitation using a mapping technique. This map associates a visual image with a sub-pixel, and has already been described. By generating maps with different pitch values, it is possible to realize an interdigitated view image optimized for a specific viewing distance as a result.

  FIG. 10 shows some embodiments using a pitch table. The pitch table can be expressed as a graph 1001 having a viewing distance defined on the x-axis 1006 and a pitch defined on the y-axis 1007. Each entry in the pitch table can be represented as a point 1008 in this graph and is represented by a specific viewing position 1009 and a pitch value 1010.

  Four examples (1002, 1003, 1004, 1005) using a pitch table are conceivable. In the first embodiment 1002, the pitch table is assumed to include a default value 1011 and its corresponding pitch 1012, which can be used when the viewing distance is not defined.

  In the second example 1003, the user 1013 designates the viewing distance. By searching for the closest viewing distance 1014 defined in the table, an appropriate pitch 1015 can be determined. A possible application in this embodiment is to allow the user to select only one of the available distances in the pitch table.

  In the third embodiment 1004, a linear interpolation process is utilized to achieve the proper pitch. In this case, if the user inputs a specific viewing distance 1016, the proportional pitch value 1018 can be reached using the primary interpolation method 1017.

  In the fourth embodiment 1005, a cubic interpolation process is utilized to achieve the proper pitch. A curve 1020 representing a function defined by pitch points is set. When the user inputs a specific viewing distance 1019, the value of the curve at that point is used as the pitch value 1021.

  When the pitch is determined, an inter-engagement map is calculated, and an optimal image corresponding to the designated viewing distance can be obtained by executing the inter-engagement using this map.

  A means for adjusting the lateral spacing of mapped sub-pixel image elements to optimize the field of view of an autostereoscopic image from within a specific viewing distance or viewing distance range has been described. The lens sheet itself remains fixed, and this adjustment is performed entirely within the array of sub-pixels that are translated horizontally to the left and right by various means. Thus, the relative juxtaposition of the subpixels is shifted left or right relative to the fixed elements of the lenticular sheet. By allowing the lens sheet element to remain in place, a realistic system for optimizing viewing distance is provided, and viewers can be at any position relative to the display screen, The clearest and deepest stereoscopic image can be seen.

It is a perspective view which shows the structure of a lenticular stereogram. It is a perspective view which shows the structure of the individual lenticule employ | adopted from the structure of FIG. 1, and a corresponding alternating fitting image. It is a perspective view which shows the test target for calibrating the pitch of a print with respect to the pitch of a lenticular screen. It is a figure which shows the apparatus used for an observer's position setting, when adjusting a lenticular screen and a test target. It is a schematic diagram showing a lenticular screen and a print row viewed from an observation point in a state where the necessary adjustment for optimizing the viewing angle is not performed. It is a schematic diagram which shows a lenticular screen and a print row seen from a distant observation point. It is a schematic diagram which shows adjustment required in order to optimize a viewing angle about a lenticular screen and a print row. FIG. 5 shows a test frame and a cylindrical stereogram print or projection display. It is a figure which shows typically the state which sees an autostereoscopic image from the near and distant place in a narrow visual field. It is a figure which shows typically the state which sees an autostereoscopic image from the near and distant place in a wide visual field. FIG. 6 is a schematic diagram illustrating a distance tracking system used in combination with the present disclosure, supplementarily utilizing FIGS. 5A and 5B. It is a conceptual diagram which shows a software alternating fitting process. It is a figure which shows typically the determination method of a lenticular pitch. It is a figure which shows typically the determination method of a subpixel mapping. 4 is a series of graphs showing four viewing distances and pitch examples.

Claims (7)

A method for optimizing the viewing distance of a lenticular stereogram,
Determine the optimal pitch value corresponding to the selected viewing distance from the stereogram,
By generating a pitch table, the viewing distance is associated with each optimal pitch value for that viewing distance,
Using the pitch table, to generate an alternately fitted view corresponding to each viewing distance,
A method involving that. A stereogram system that provides an image that is closely juxtaposed with a lenticular screen,
A data storage device configured as a table in which specified viewing distances from the stereogram are associated with individual optimal pitch values of the lenticular screen;
An alternating fitting program that operates on the table and generates mapping of the alternating fitting visual image corresponding to each viewing distance based on the optimum pitch value;
Including system.   The system of claim 2, further comprising a selection device for selecting a desired viewing distance.   The system of claim 3, wherein a default value is provided for a desired viewing distance that does not have an associated pitch value.   4. The system of claim 3, wherein for a desired viewing distance that does not have an associated pitch value, the pitch value associated with the viewing distance closest to the desired viewing distance is selected.   4. The system of claim 3, wherein for a desired distance that does not have an associated pitch value, an associated pitch value is determined using a linear interpolation process.   4. The system of claim 3, wherein for a desired distance that does not have an associated pitch value, an associated pitch value is determined using a cubic interpolation process.

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