JP2009064086A - Image-processing program, computer-readable recording medium recording the program, image processor and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide image processing technology allowing further heightening expressive power of an outline. <P>SOLUTION: This image processor (a) perspectively projects a virtual three-dimensional space disposed with an object, and generates basic image data (S11), (b) performs outline extraction by use of the basic image data to generate first outline image data (S12), (c) reads a transparency parameter set associatively to at least a part of the object from a storage means (S13), (d) generates transparency map data representing transparency based on the transparency parameter (S14), (e) mixes the first outline image data and the transparency map data to generate second outline image data (S15), and (f) composes the second outline image data and the basic image data to generate two-dimensional image data (S16). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for generating a two-dimensional image by perspective-projecting an event set in a virtual three-dimensional space.

  With the development of computer technology in recent years, image processing technology relating to video game devices, simulators (pseudo-experience devices), etc. has become widely popular. In such a system, it is important to make the displayed image richer in expressiveness in order to increase the product value. In such a background, expressions that are close to reality (realistic expressions) are distinct, and hand-drawn image expressions such as watercolor styles or drawing styles are being studied. One of the elements necessary for handwritten image expression is to naturally express the outline of each object (for example, a character such as a person). The prior art regarding such contour expression is disclosed in, for example, Japanese Patent Application Laid-Open No. 2007-26111 (Patent Document 1).

  However, the conventional technique may cause inconvenience in the expression of a hair portion in an image of an object representing a person, for example. More specifically, the hair density of the hair portion is closer to the base of the hair, such as the top of the head, and the hair density decreases as the distance from the hair portion increases. If a contour is drawn on the hair portion expressed with a light hair density, the contour becomes too conspicuous, resulting in a visually uncomfortable image. Such a technical problem is not limited to the image representation of hair, but is common to other image representations (for example, cell-like image representation).

JP 2007-26111 A

  Accordingly, an object of the present invention is to provide an image processing technique capable of further enhancing the expressiveness of the contour.

  A program according to the present invention is executed by an image processing apparatus including a storage unit and a calculation unit, and obtains two-dimensional image data obtained by perspective projection of a virtual three-dimensional space in which an object is arranged on a predetermined perspective projection plane. A program to be generated, wherein the arithmetic means (a) perspectively projects the virtual three-dimensional space in which the objects are arranged on the perspective projection plane set corresponding to the viewpoint, and obtains basic image data. Generating and storing the basic image data in the storage means; and (b) generating first contour image data by performing contour extraction using the basic image data, and generating the first contour image data. Storing in the storage means, and (c) a step of reading from the storage means a transparency parameter set in association with at least a part of the object. (D) generating transparency map data representing transparency based on the transparency parameter, and storing the transparency map data in the storage means; (e) the first contour image data and the transparency Generating second contour image data by mixing the map data; and (f) generating the two-dimensional image data by combining the second contour image data and the basic image data. Are executed.

  The above “at least part of the object” is, for example, a hair end of a human character. Further, (a) described above may include a process of mapping a texture including an image representing hair to the at least part of the object.

  By executing the program according to the present invention, the first contour image data and the transparency map data are mixed to obtain second contour image data in which a contour having light and shade is represented. By synthesizing the second contour image data with the basic image data, two-dimensional image data in which the density of the contour is freely expressed can be obtained. For example, taking the above-described hair as an example, the contour density can be set to a desired state, for example, the contour becomes thinner as it approaches the hair tip. As described above, according to the present invention, it is possible to further enhance the expressiveness of the contour.

  In the second contour image data, for example, the contour corresponding to the portion with low transparency represented by the transparency map data is relatively dark and the contour corresponding to the portion with high transparency is relatively thin. Can be set as follows.

  The computer-readable recording medium according to the present invention is a recording medium on which the program according to the present invention is recorded. The present invention can also be expressed as an image processing apparatus and an image processing method as follows. The effects in that case are the same as described above.

  An image processing apparatus according to the present invention includes a storage unit and a calculation unit, and generates two-dimensional image data obtained by perspective projection of a virtual three-dimensional space in which an object is arranged on a predetermined perspective projection plane. The arithmetic means (a) perspectively projects the virtual three-dimensional space in which the object is arranged on the perspective projection plane set corresponding to the viewpoint to generate basic image data, Means for storing the basic image data in the storage means; (b) generating first contour image data by performing contour extraction using the basic image data; and storing the first contour image data in the storage means. (C) means for reading a transparency parameter set in association with at least a part of the object from the storage means; and (d) based on the transparency parameter. Means for generating transparency map data representing transparency and storing the transparency map data in the storage means; (e) second contour image data by mixing the first contour image data and the transparency map data; And (f) means for generating the two-dimensional image data by synthesizing the second contour image data and the basic image data.

  In an image processing method according to the present invention, two-dimensional image data obtained by perspective projection of a virtual three-dimensional space in which an object is arranged on a predetermined perspective projection plane in an image processing apparatus including a storage unit and a calculation unit. In the image processing method to be generated, the calculation means (a) performs a perspective projection on the perspective projection plane set corresponding to the viewpoint, and (a) a basic image in which the virtual three-dimensional space in which the object is arranged is projected. Generating data and storing the basic image data in the storage means; and (b) generating first contour image data by performing contour extraction using the basic image data, and generating the first contour Storing image data in the storage means; and (c) reading from the storage means transparency parameters set in association with at least a part of the object. (D) generating transparency map data representing transparency based on the transparency parameter, and storing the transparency map data in the storage means; (e) the first contour image data and the transparency map data; And (f) generating the two-dimensional image data by synthesizing the second contour image data and the basic image data; and Each of the above is executed.

  Embodiments of the present invention will be described below. In the following, a game device is taken as an example of an image processing device.

  FIG. 1 is a block diagram illustrating a configuration of a game device according to an embodiment. 1 includes a CPU (Central Processing Unit) 10, a system memory 11, a storage medium 12, a boot ROM (BOOT ROM) 13, a bus arbiter 14, a GPU (Graphics Processing Unit) 16, and a graphic memory 17. , An audio processor 18, an audio memory 19, a communication interface (I / F) 20, and a peripheral interface 21. That is, the game apparatus 1 of this embodiment includes a CPU 10 and a GPU 16 as calculation means (calculation unit), a system memory 11 as a storage means (storage unit), a storage medium 12, a graphic memory 17, an audio memory 19, and the like. Composed. In other words, the game apparatus 1 includes a computer (computer system) mainly configured by the CPU 10 and functions as a game apparatus by causing the computer to execute a predetermined program. Specifically, the game device 1 sequentially generates two-dimensional images (still images or moving images) as seen in a virtual three-dimensional space (game space) from a given viewpoint (virtual camera) in order to perform a game effect. In addition, sound such as sound effects is generated.

  A CPU (Central Processing Unit) 10 controls the entire game apparatus 1 by executing a predetermined program.

  The system memory 11 stores programs and data used by the CPU 10. The system memory 11 is configured using a semiconductor memory such as a DRAM (dynamic random access memory) and an SRAM (static random access memory).

  The storage medium 12 stores data such as game programs and output images and sounds. The storage medium 12 as the program data ROM includes an IC memory that can electrically read data such as mask chrome and flash ROM, a device that can read data optically such as a CD-ROM and a DVD-ROM, and an optical disk or magnetic disk. It may be a disc or the like.

  The boot ROM 13 stores a program for initializing each block when the game apparatus 1 is activated.

  The bus arbiter 14 controls a bus for exchanging programs and data between the blocks.

  The GPU 16 generates an image to be output to the display based on the calculation of the position coordinates and orientation (geometry calculation) of the object displayed on the display in the virtual three-dimensional space (game space) and the orientation and position coordinates of the object. Perform processing (rendering processing).

  The graphic memory 17 is connected to the GPU 16 and stores data and commands for generating an image. The graphic memory 17 is configured using a semiconductor memory such as a DRAM (dynamic random access memory) or an SRAM (static random access memory). The graphic memory 17 functions as various buffers used during image generation, such as a frame buffer and a texture buffer.

  The audio processor 18 generates data for outputting sound from the speaker. The audio data generated by the audio processor 18 is converted into an analog signal by a digital / analog converter (not shown) and input to the speaker, so that the speaker outputs audio.

  The audio memory 19 is configured in the audio processor 18 and stores data and commands for generating sound. The audio memory 19 is configured using a semiconductor memory such as a DRAM (dynamic random access memory) or an SRAM (static random access memory).

  The communication interface (I / F) 20 performs communication processing when the game apparatus 1 needs to perform data communication with other game apparatuses, server apparatuses, and the like.

  The peripheral interface (I / F) 21 incorporates an interface for inputting and outputting data from the outside, and a peripheral as a peripheral device is connected thereto. Here, peripherals include a mouse (pointing device), a keyboard, switches for key operations such as a game controller, and a touch pen, as well as a backup memory for storing program progress and generated data, a display device, and shooting. And devices that can be connected to the image processing apparatus main body or other peripherals.

The system memory 11, the graphic memory 17, and the sound memory 19 may be connected to the bus arbiter 14 and used in common for each function. Moreover, each functional block should just exist as a function, and functional blocks may be integrated, and each component inside a functional block may be isolate | separated as another block.

  The game device according to the present embodiment has the above-described configuration. Next, the contents of the image generation processing of the present embodiment will be described.

  FIG. 2 is a conceptual diagram showing each of an object (virtual object), a light source, and a viewpoint arranged in a virtual three-dimensional space. The object 300 is a virtual object formed by combining one or a plurality of polygons. The object 300 refers to any virtual object that can be placed in a virtual three-dimensional space, such as a living thing such as a human being or an animal, or a building, a car, or another inanimate object. The virtual three-dimensional space is expressed by a world coordinate system defined by three axes (XYZ) orthogonal to each other. The object 300 is represented by an object coordinate system that is different from the world coordinate system, for example. The light source 302 is disposed at an arbitrary position in the virtual three-dimensional space. This light source 302 is, for example, an infinite light source. The position, direction, and intensity of the light source 302 are expressed by a light vector L. In the present embodiment, the length of the light vector L (in other words, the light intensity) is normalized to 1. The viewpoint 304 is defined by the viewpoint position (coordinates in the world coordinate system) and the line-of-sight direction. For example, the direction of the arrow C shown in the figure is the line-of-sight direction. This viewpoint 304 may be called a camera, a virtual camera, or the like.

  FIG. 3 is a diagram schematically illustrating an example of a two-dimensional image generated by the image processing method of the present embodiment. Specifically, the two-dimensional image shown in FIG. 3 includes an image representing a portion from a person's face to a shoulder. As described above, the two-dimensional image represents a state in which the virtual three-dimensional space is viewed from the viewpoint 304 (see FIG. 2). The image processing method of this embodiment is used, for example, to improve the expressiveness of the hair tip portion in such a two-dimensional image. The details will be described below with reference to flowcharts.

  FIG. 4 is a flowchart showing a flow of image processing executed by the game device (image processing device) of the present embodiment. The overall image processing flow of the present embodiment includes an object 300, a viewpoint 304, and a light source 302 (see FIG. 2), and rendering processing (coordinate conversion, clipping, perspective projection conversion, hidden surface removal, shading, shadowing). Ing, texture mapping, etc.), and further processing on the tip of the hair is performed. Note that the processing described below can change the processing order or perform each processing in parallel as long as the results do not contradict each other.

  Based on the data read from the system memory 11, the CPU 10 arranges an object (polygon model) configured by combining a plurality of polygons in the virtual three-dimensional space (step S10).

  The CPU 10 sets the light source and the viewpoint, and the basic image data is generated by the GPU 16 correspondingly (step S11). The position of the viewpoint is set, for example, at a certain distance behind the object operated by the player. The position of the light source is fixed at a predetermined position, for example, or moves with time. The GPU 16 performs each process (rendering process) such as coordinate conversion, clipping, perspective projection conversion, hidden surface removal, etc., corresponding to each setting of the light source and the viewpoint. Thereby, an image obtained by perspective projection of the virtual three-dimensional space in which the object is arranged on the perspective projection plane is obtained. In the present embodiment, this image data is referred to as “basic image data”. The basic image data is stored in a frame buffer set in the graphic memory 17. The content of the basic image data is obtained by removing the line indicating the outline from the two-dimensional image data shown in FIG. 3 (not shown).

  Next, the GPU 16 generates first contour image data by performing contour extraction using the basic image data (step S12). As a specific method of contour extraction, a known technique may be appropriately used. For example, the contour can be extracted by detecting a portion where the color is greatly changed using color information included in the basic image data. In addition, a method such as a contour extraction method (depth edge extraction) using depth in the depth direction (depth map) or a contour extraction method (normal edge extraction) using a normal map may be used. An example of the first contour image data obtained in this step in this way is shown in FIG. The first outline image data shown in FIG. 5 is generated based on the basic image data shown in FIG. 3 and includes the hair outline, face and neck outline, and shoulder outline of the human character. ing. The first contour image data is stored in the graphic memory 17.

  Next, the GPU 16 reads the transparency parameter set in association with at least a part of the object 300 from the storage medium 12 (step S13). “At least a part of the object 300” is a portion set as a portion where the density of the contour is desired to be expressed step by step, and corresponds to the hair tip portion of the human character in the present embodiment. A transparency parameter (transparency control value) is prepared in advance in association with the tip of the hair and stored in the storage medium 12. As an example, this transparency parameter is stored as texture data. Specifically, the texture data includes color components (R, G, B) and an alpha value (A), and among these, a transparency parameter can be prepared as an alpha value. Note that the transparency parameter may be prepared in another format without using the texture data format.

  Next, the GPU 16 generates transparency map data representing transparency based on the transparency parameter read from the storage medium 12 in step S13 (step S14). The transparency map data is grayscale image data having a shade corresponding to a portion whose contour is desired to be controlled, and has the same size as the basic image data. The transparency map data generated in this step is stored in the graphic memory 17.

  FIG. 6 is a diagram schematically showing the transparency map data generated in this step. FIG. 7 is a further enlarged view of a part surrounded by a dotted line in FIG. In each figure, the shading is expressed in gray scale. The part where the contour is to be darkened is closer to black, and the part where the contour is to be thinner is closer to white. That is, a location with low transparency corresponds to a location where the contour is desired to be expressed deeply, and a location with high transparency corresponds to a location where the contour is desired to be expressed lightly (or the contour is desired to be hidden).

  Next, the GPU 16 generates the second contour image data by mixing the first contour image data (see FIG. 5) and the transparency map data (see FIGS. 6 and 7), and generates a graphic memory. 17 (step S15). Specifically, the first contour image data and the transparency map data are multiplied for each pixel. Thereby, the brightness of each pixel of the first contour image data changes according to the transparency of each pixel. FIG. 8 schematically shows this state. As shown in FIG. 8, the contour density changes stepwise according to the density of the transparency map data. In FIG. 8, for the convenience of illustration, the contour density is changed in four stages, but in practice, it is a substantially continuous change. In the example shown in FIG. 8, no outline is displayed for the portion corresponding to the tip of the hair tip. In order to express this, the outline of the portion corresponding to the tip of the hair tip is displayed with a dotted line.

  Next, the GPU 16 generates two-dimensional image data by combining the second contour image data and the basic image data, and stores the two-dimensional image data in the graphic memory 17 (step S16). Of the two-dimensional image data (see FIG. 3) obtained by synthesizing the second contour image data (that is, image data including the contour expressed in shading) and the basic image data, only the hair tip portion is enlarged and modeled. This is shown in FIG. The outline is gradually thinned toward the tip of the hair tip. As a result, the familiarity between the texture representing the hair and the contour is improved.

  In the example of the two-dimensional image data shown in FIG. 9, the density of the portion representing the hair tip itself is gradually decreased and gradually becomes transparent as it approaches the tip of the hair tip. In step S11 described above, for example, the following processing is performed. As shown in FIG. 10, the tip of the hair is modeled by combining a plurality of polygons. At this time, the transparency of the hair texture is set as the alpha value of each polygon. Schematically, the alpha value of the polygon closer to the root of the hair is set to α = 1.0 or a value close thereto (for example, the polygon pg1 shown in the figure). This corresponds to the opaque state. And as it approaches the hair end, the alpha value is set to a lower value. For example, the alpha value of the polygon pg close to the hair tip is set to Α = 0.5 or a value close thereto (for example, the illustrated polygon pg2). This corresponds to the translucent state. The alpha value is set to α = 0.0 or a value close to this for the hair tip or a polygon close thereto (for example, the polygon pg3 shown in the figure). This corresponds to the transparent state. A hair texture as illustrated in FIG. 11 is mapped to each polygon. As a result, the texture is mapped at a rate corresponding to the alpha value of each polygon, and as shown in FIG. 9, it is possible to generate an image of the hair whose transparency changes continuously.

  As described above, according to the present embodiment, by mixing the first contour image data and the transparency map data, second contour image data in which a contour having light and shade is expressed is obtained. By synthesizing the second contour image data with the basic image data, two-dimensional image data in which the density of the contour is freely expressed can be obtained. Thereby, in the example of head hair, the outline of a contour can be made into a desired state, for example, a contour is thinly expressed as it approaches a hair tip. As described above, according to the present embodiment, it is possible to further increase the expressiveness of the contour.

  In addition, this invention is not limited to the content of each embodiment mentioned above, A various deformation | transformation implementation is possible within the scope of the summary of this invention. For example, in the above-described embodiment, the expression of the contour in the hair tip portion of a human character is shown as a typical example to which the image processing technique according to the present invention is applied, but the scope of application of the present invention is limited to this. It is not a thing.

  In the above-described embodiment, the game device is realized by causing a computer including hardware such as a CPU to execute a predetermined program. However, each functional block provided in the game device is dedicated hardware or the like. It may be realized using.

  In the above description, the game apparatus is taken as an example, and the embodiments of the image processing apparatus, the image processing method, and the image processing program according to the present invention have been described. However, the scope of the present invention is not limited to this. For example, the present invention can also be applied to a simulator device or the like that reproduces various real world experiences (for example, driving operations) in a pseudo manner.

It is a block diagram which shows the structure of the game device of one Embodiment. It is the conceptual diagram shown about each of the object (virtual object) arrange | positioned in virtual three-dimensional space, a light source, and a viewpoint. It is the figure which showed typically an example of the two-dimensional image produced | generated by the image processing method of this embodiment. It is a flowchart which shows the flow of the image processing performed by the game device (image processing device) of this embodiment. It is a figure which shows an example of 1st outline image data. It is the figure which visualized and expressed transparency map data typically. It is the figure which expanded and showed a part enclosed with the dotted line in FIG. It is the figure which showed typically a mode that the density of an outline changed in steps according to the lightness and darkness of transparency map data. It is the figure which expanded and showed typically only the hair tip part among the two-dimensional image data obtained by synthesize | combining 2nd outline image data and basic image data. It is the figure which showed typically a mode that the hair tip part was modeled combining the some polygon. It is the figure which illustrated the texture of hair.

Explanation of symbols

10 ... CPU
11 ... System memory 12 ... Storage medium 13 ... Bootrom 14 ... Bus arbiter 16 ... GPU
17 ... Graphic memory 18 ... Audio processor 19 ... Audio memory 20 ... Communication interface (I / F)
21 ... Peripheral interface

Claims (13)

A program that is executed by an image processing apparatus including a storage unit and a calculation unit and generates two-dimensional image data obtained by perspective projection of a virtual three-dimensional space in which an object is arranged on a predetermined perspective projection plane,
In the calculation means,
(A) The virtual three-dimensional space in which the object is arranged is perspective projected onto the perspective projection plane set corresponding to the viewpoint to generate basic image data, and the basic image data is stored in the storage unit Storing, and
(B) generating first contour image data by performing contour extraction using the basic image data, and storing the first contour image data in the storage unit;
(C) reading from the storage means a transparency parameter set in association with at least a part of the object;
(D) generating transparency map data representing transparency based on the transparency parameter, and storing the transparency map data in the storage means;
(E) generating second contour image data by mixing the first contour image data and the transparency map data;
(F) generating the two-dimensional image data by combining the second contour image data and the basic image data;
A program that executes In the second contour image data, the contour corresponding to the portion with low transparency represented by the transparency map data is relatively dark, and the contour corresponding to the portion with high transparency is relatively thin.
The program according to claim 1. The at least part of the object is a hair end of a human character;
The program according to claim 1 or 2. (A) includes a process of mapping a texture including an image representing hair to the at least part of the object;
The program according to claim 3.   The computer-readable recording medium which recorded the program in any one of Claims 1 thru | or 4. An image processing apparatus that includes storage means and calculation means, and generates two-dimensional image data obtained by perspective projection of a virtual three-dimensional space in which an object is arranged on a predetermined perspective projection plane,
The computing means is
(A) The virtual three-dimensional space in which the object is arranged is perspective projected onto the perspective projection plane set corresponding to the viewpoint to generate basic image data, and the basic image data is stored in the storage unit Means for storing,
(B) means for generating first contour image data by performing contour extraction using the basic image data, and storing the first contour image data in the storage means;
(C) means for reading a transparency parameter set in association with at least a part of the object from the storage means;
(D) means for generating transparency map data representing transparency based on the transparency parameter, and storing the transparency map data in the storage means;
(E) means for generating second contour image data by mixing the first contour image data and the transparency map data;
(F) means for generating the two-dimensional image data by combining the second contour image data and the basic image data;
An image processing apparatus that functions as each of the above. In the second contour image data, the contour corresponding to the portion with low transparency represented by the transparency map data is relatively thin, and the contour corresponding to the portion with high transparency is relatively dark.
The image processing apparatus according to claim 6. The at least part of the object is a hair end of a human character;
The image processing apparatus according to claim 6 or 7. The means (a) includes a process of mapping a texture including an image representing hair to the at least part of the object.
The image processing apparatus according to claim 8. In an image processing apparatus including a storage unit and a calculation unit, an image processing method for generating two-dimensional image data obtained by perspective projection of a virtual three-dimensional space in which an object is arranged on a predetermined perspective projection plane,
The computing means is
(A) The virtual three-dimensional space in which the object is arranged is perspective projected onto the perspective projection plane set corresponding to the viewpoint to generate basic image data, and the basic image data is stored in the storage unit Storing, and
(B) generating first contour image data by performing contour extraction using the basic image data, and storing the first contour image data in the storage unit;
(C) reading from the storage means a transparency parameter set in association with at least a part of the object;
(D) generating transparency map data representing transparency based on the transparency parameter, and storing the transparency map data in the storage means;
(E) generating second contour image data by mixing the first contour image data and the transparency map data;
(F) generating the two-dimensional image data by combining the second contour image data and the basic image data;
An image processing method for executing each of the above. In the second contour image data, the contour corresponding to the portion with low transparency represented by the transparency map data is relatively thin, and the contour corresponding to the portion with high transparency is relatively dark.
The image processing method according to claim 10. The at least part of the object is a hair end of a human character;
The image processing method according to claim 10 or 11. (A) includes a process of mapping a texture including an image representing hair to the at least part of the object;
The image processing method according to claim 12.