JP2008257431A - Image display device and image display method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device for performing highly precise solid image display accompanied with shading processing without improving the capability of a display device. <P>SOLUTION: This image display device for displaying an image to which shading processing has been applied is provided with; a display means for displaying an image; a plurality of shaders whose precision of the shading processing to be applied to image data as the object of rendering is different; an image data storage means for storing image data to be displayed on the display means; a visual acuity data storage means for preliminarily defining a relation between the moving speed of a moving object and dynamic visual acuity; a viewpoint position calculation means for calculating the viewpoint position of a viewer; a dynamic visual acuity acquisition means for calculating the moving speed of image data to be rendered, and for acquiring the dynamic visual acuity corresponding to the calculated moving speed by referring to the visual acuity data storage means; and a shading processing means for selecting the highly precise shader corresponding to the acquired dynamic visual acuity, and for applying shading processing by using the selected shader to the image data to be rendered. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image display device and an image display method capable of reducing a calculation load when generating an image to be drawn.

Conventionally, in the real-time stereoscopic image display method, the entire image displayed on the screen is generated by the same image generation algorithm regardless of where the operator is gazing at the display screen. In order to solve the problem of high image quality, an image display method is known in which the operator's viewpoint is obtained, and the calculation load is reduced by reducing the definition of the image to be displayed in a region other than the periphery of the viewpoint (for example, , See Patent Document 1).
Japanese Patent No. 3478606

  By the way, in recent years, images generated in real time have become particularly high-definition as technology advances, and both the amount of model data and the calculation load of shaders (shadow processing programs) have been increasing in search of more realistic expressions. ing. However, since the processing capability of the hardware is not sufficient, it is difficult to ensure real time performance. In particular, in order to generate a stereoscopic video, it is necessary to generate at least two images per frame, and therefore a further reduction in calculation load is required compared to a two-dimensional image. In addition, in order to increase the definition of a stereoscopic image, it is necessary to perform a shading process using a shader. However, it is necessary to perform the shading process for each polygon constituting an object (an object in the image) included in the image. Therefore, there is a problem that the calculation load increases according to the number of polygons included in the image. Therefore, since it is difficult to display in real time the number of polygons exceeding the capacity of the display device, the capability of the display device must be improved according to the content of the image to be displayed. There is also a problem that the cost becomes high.

  The present invention has been made in view of such circumstances, and an image capable of performing high-definition stereoscopic image display with shadow processing without improving the capability of the display device for stereoscopic image display with shadow processing. An object is to provide a display device and an image display method.

  The present invention is an image display device that displays an image subjected to a shadow process, a display unit that displays an image, and a plurality of shaders having different definition of the shadow process performed on image data to be rendered, Image data storage means in which image data to be displayed on the display means is stored; visual acuity data storage means in which the relationship between the moving speed of the moving object and the moving visual acuity is predefined; and viewpoint position calculation for determining the viewer's viewpoint position A moving visual acuity acquisition means for obtaining a moving visual acuity corresponding to the obtained moving speed with reference to the visual acuity data storage means and obtaining a moving speed of the image data to be drawn; The image processing apparatus includes a shadow processing unit that selects the shader having a high definition and performs a shadow process on the image data to be drawn using the selected shader.

  In the present invention, the shading processing means is characterized in that a unit of image data to be subjected to the shading processing is a polygon or a pixel.

  According to the present invention, the visual acuity data storage means defines a relationship between each of KVA moving visual acuity and DVA moving visual acuity and a moving speed of the moving object, and the image is a stereoscopic image.

  In order to display an image subjected to shadow processing, the present invention provides a display means for displaying an image, a plurality of shaders with different degrees of definition of the shadow processing applied to image data to be drawn, and the display means. An image display method in an image display device comprising: image data storage means storing image data to be displayed; and visual acuity data storage means in which a relationship between a moving speed of a moving object and a moving visual acuity is predefined. A viewpoint position calculating step for obtaining a viewpoint position of the person, a moving eyesight obtaining step for obtaining a moving eyesight corresponding to the obtained moving speed by obtaining a moving speed of image data to be drawn and referring to the eyesight data storage unit And selecting the shader with a definition corresponding to the acquired moving visual acuity, and performing shadow processing on the image data to be drawn using the selected shader And having a physical step.

  According to the present invention, in a shading process in which the amount of calculation increases in proportion to the complexity of an image, a moving speed (relative speed with respect to the viewpoint) is obtained for each polygon or pixel to be drawn, and a shader corresponding to the moving speed is obtained. Therefore, it is possible to draw a complex image (an image having a large number of polygons to be drawn) without improving the performance of the hardware for drawing. As a result, it is possible to reduce the amount of calculation without the viewer recognizing a decrease in image quality.

  Hereinafter, an image display device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the embodiment. In this figure, reference numeral 1 denotes a drawing unit that draws an image by comprehensively controlling the processing operation of the image display apparatus. Reference numeral 2 denotes a display unit for displaying an image, which is composed of a liquid crystal display, a projector, or the like. Reference numeral 3 denotes a frame buffer that temporarily stores image data to be displayed on the display unit 2. Reference numeral 4 denotes an image data storage unit in which stereoscopic image data to be displayed on the display unit 2 is stored in advance. Reference numeral 5 denotes a visual acuity data storage unit in which standard human visual acuity data is stored in advance. Reference numeral 6 denotes a shader storage unit in which a plurality of types of shaders (shading process programs) for performing a shadow process on the image data stored in the image data storage unit 4 are stored in advance.

  Here, human visual acuity will be described. The dynamic visual acuity is a visual acuity when viewing an object moving relative to the viewpoint, and is inferior to a static visual acuity. There are two types of human visual acuity: KVA (Kinetic Visual Acuity) dynamic visual acuity and DVA (Dynamic Visual Acuity) dynamic visual acuity. The KVA moving body visual acuity is visual acuity when moving in the front-rear direction with respect to the viewpoint, and is related to a change in the thickness of the lens by the ciliary muscle. On the other hand, DVA moving body visual acuity is visual acuity when moving in the horizontal direction with respect to the viewpoint, and is related to eye movement by the extraocular muscles. FIG. 3 shows the relationship between each moving object visual acuity and the moving speed (cited from JP 2000-237133 A). As shown in FIG. 3, the visual acuity of both the KVA moving body visual acuity and the DVA moving body visual acuity decreases as the speed of the moving body increases. In two-dimensional images, the lens thickness does not change because there is no need to move the focal point in the front-rear direction. However, in the three-dimensional image, the focal point movement in the front-rear direction is necessary. To do. Therefore, in the shadow processing of a moving object included in a stereoscopic image, the calculation time can be greatly shortened by selecting an optimum shader according to the moving object visual acuity and performing the shadow processing calculation. The visual acuity data storage unit 5 shown in FIG. 1 stores data in which the relationship between speed (or angular velocity) and visual acuity is defined for each of the two moving object visual acuities shown in FIG. Therefore, when the speed or angular velocity is determined, it is possible to obtain either of the two moving object visual acuities corresponding to these speeds or angular velocities with reference to the visual acuity data storage unit 5.

  Next, the operation of the image display apparatus shown in FIG. 1 will be described with reference to FIG. First, the drawing unit 1 obtains viewpoint position information in the virtual space when referring to an image stored in the image data storage unit 4. The viewpoint position information obtains the positions of the viewer's eyes and the width / height of the drawing surface, and obtains the left and right viewpoint positions in the virtual space based on them (step S1). Next, the drawing unit 1 obtains drawing parameters to be applied to each of the KVA moving object visual acuity and the DVA moving object visual acuity from the angle of view of the image to be generated (step S2). The drawing parameters are obtained as follows. When the angle of view of the generated image is small, the drawing parameter is set to a small value so that the influence of the KVA moving body visual acuity is small, and the drawing parameter is set to a large value so that the influence of the DVA moving body visual acuity is large. On the other hand, when the angle of view of the generated image is large, the drawing parameter is set to a large value so that the influence of the KVA moving body visual acuity becomes large, and the drawing parameter is set to a small value so that the influence of the DVA moving body visual acuity becomes small.

  Next, the front-rear direction velocity and the horizontal angular velocity with respect to the viewpoint are obtained from the movement amount, movement direction, and frame rate of the target polygon to be drawn, and the product of the parameters obtained in step S2 is calculated. The drawing unit 1 refers to the visual acuity data storage unit 5 and the KVA moving body visual acuity corresponding to the obtained two product values (the longitudinal velocity multiplied by the drawing parameter and the horizontal angular velocity). The DVA moving body visual acuity is obtained (step S3). When the moving object is sufficiently far from the viewpoint, even if the moving object moves in the front-rear direction, the human eye cannot recognize the difference in distance. The human visual acuity (detection limit of phase difference between two lines in contact with each other) is about 10 seconds, and anyone can distinguish if the convergence angle is 20 seconds. When the convergence angle is 20 seconds, the distance from the viewpoint to the moving object is about 650 m. Therefore, when the distance from the viewpoint to the target polygon is 650 m or more, KVA visual acuity is not considered.

  Next, the drawing unit 1 obtains a parameter indicating the ease of perception from the surface texture of the target polygon (step S4). Since the ease of perception of a moving object depends on the pattern / pattern on the surface of the object, the calculation load can be further reduced if the surface texture of the target polygon is difficult to perceive. Subsequently, the drawing unit 1 calculates the product of each value of the KVA moving body visual acuity and the DVA moving body visual acuity obtained in step S3 and the perceptibility parameter obtained in step S4, and selects a shader corresponding to the value. (Step S5). The shader storage unit 6 is associated with a shader to be used and a product value of each value of the KVA moving body visual acuity and the DVA moving body visual acuity and a parameter of ease of perception. The drawing unit 1 refers to this relationship and selects an optimum shader.

  Next, the drawing unit 1 performs an operation for shading processing on the polygon to be drawn by the selected shader (step S6), and writes the obtained result as drawing data in the frame buffer 3 (step S6). S7). The drawing unit 1 writes one frame of drawing data into the frame buffer 3 by executing the processing of steps S2 to S7 for all the polygons to be written into the frame buffer 3. As a result, drawing data subjected to different shading processing for each polygon moving speed is written in the frame buffer 3. That is, when the moving speed (relative speed with respect to the viewpoint) is high, low-definition shading processing is performed, and when the moving speed is slow, the drawing data is subjected to high-definition shading processing. The display unit 2 performs image display by sequentially reading the drawing data written in the frame buffer 3.

  Thus, by generating drawing data in consideration of the KVA moving body visual acuity, it is possible to reduce the calculation amount without recognizing a decrease in image quality as compared with the conventional method. In addition, since a shader is selected for each polygon, when a shader with a light calculation load is applied, drawing data can be generated without degradation in image quality uniformly in the object as in the conventional method. It becomes possible.

  In the above-described method, an example in which a shader to be applied is selected for each polygon has been described. However, a shader to be applied may be selected not for each polygon but for each surface texture pixel. By doing in this way, since the texture pixel is generally smaller than the polygon, the movement speed can be calculated more strictly, so that the calculation amount can be further reduced. In addition, the influence of polygon rotation / texture animation on visual acuity, which could not be considered for polygons, can also be considered.

  In FIG. 1, an example in which a plurality of shader programs are stored in the shader storage unit 6 is shown. However, instead of a plurality of shader programs, a plurality of dedicated hardware that executes shading is provided, The shadow processing may be executed by selecting these dedicated hardware.

  In this way, in shade processing where the amount of calculation increases in proportion to the complexity of the image, the moving speed (relative speed with respect to the viewpoint) is calculated for each polygon or pixel to be drawn, and a shader corresponding to the moving speed is selected. Therefore, it is possible to draw a complex image (an image having a large number of polygons to be drawn) without improving the performance of hardware for drawing. As a result, the amount of calculation can be reduced without the viewer perceiving a decrease in image quality.

  In particular, when the target object is moving or the viewpoint is moving, the human visual acuity is lower than when the target object is stationary. Accordingly, the optimum shadow calculation method is selected according to the above, so that the calculation load can be reduced without the viewer perceiving a decrease in the quality of the generated image. In addition, since the drawing data is generated in consideration of the influence of the KVA moving visual acuity which is important for the stereoscopic image display, it is possible to reduce the calculation amount of the shadow processing without causing the viewer to recognize the deterioration of the image quality. is there. In the conventional method, the same shading calculation method is used regardless of the moving speed of the target object. Therefore, when using a lightly loaded method, a decrease in image quality is recognized if the target object is stationary. Since the optimum shader is selected according to the moving speed of the polygon, it is possible to prevent the viewer from recognizing the deterioration of the image quality.

  The program for realizing the function of the processing unit in FIG. 1 is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed to execute image display processing. You may go. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer system” includes a WWW system having a homepage providing environment (or display environment). The “computer-readable recording medium” refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, and a CD-ROM, and a storage device such as a hard disk built in the computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included.

  The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

It is a block diagram which shows the structure of one Embodiment of this invention. It is a flowchart which shows operation | movement of the drawing part 1 shown in FIG. It is explanatory drawing which shows an example of the data memorize | stored in the visual acuity data storage part 5 shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Drawing part, 2 ... Display part, 3 ... Frame buffer, 4 ... Image data storage part, 5 ... Visual acuity data storage part, 6 ... Shader storage part

Claims (4)

An image display device that displays an image subjected to shading processing,
Display means for displaying an image;
A plurality of shaders having different definition of the shading process applied to the image data to be rendered;
Image data storage means storing image data to be displayed on the display means;
A visual acuity data storage means in which the relationship between the moving speed of the moving object and the dynamic visual acuity is predefined;
Viewpoint position calculating means for determining the viewer's viewpoint position;
Obtaining a moving speed of image data to be drawn, referring to the visual acuity data storage means, and obtaining a moving visual acuity corresponding to the obtained moving speed;
An image comprising: shade processing means for selecting the shader having a definition corresponding to the acquired moving visual acuity and performing a shadow process on the image data to be drawn using the selected shader. Display device.   The image display apparatus according to claim 1, wherein a unit of image data on which the shadow processing unit performs the shadow processing is a polygon or a pixel.   3. The image according to claim 1, wherein the visual acuity data storage means defines a relationship between a moving speed of the moving object and each of the KVA moving object visual acuity and the DVA moving object visual acuity, and the image is a stereoscopic image. Display device. In order to display an image that has undergone shading processing, display means for displaying an image, a plurality of shaders with different degrees of definition of the shading processing applied to image data to be rendered, and an image to be displayed on the display means An image display method in an image display device comprising: image data storage means storing data; and visual acuity data storage means in which a relationship between a moving speed of a moving object and a moving visual acuity is predefined,
A viewpoint position calculating step for obtaining the viewpoint position of the viewer;
Obtaining a moving speed of image data to be drawn, referring to the visual acuity data storage means, and obtaining a moving visual acuity corresponding to the obtained moving speed; and
A shadow processing step of selecting the shader with a definition corresponding to the acquired moving object visual acuity and performing a shadow process on the image data to be drawn using the selected shader. Method.

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