JPH10143675A - Computer graphics reproducing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reproduce an image which has reality feeling that is equal to or more than a hard copy that is created by using a picked up photograph when a three-dimensional image which is created through computer graphics by generating image data for image reproduction in which a reproduced image has appearance that is the same image with an appearance 3 stimulation value. SOLUTION: An appearance 3 stimulation value which shows a two-dimensional image that is projected on a plane 16 which is optionally formed in CG virtual space, i.e., appearance signals α, β and γ are acquired from information of an object 10, a light source 12 and an observer 14 in a three-dimensional coordinates (x, y and z) in a CG space when a CG image that is created in a virtual space (simulation space) of a CG (computer graphics) is reproduced in a hard copy. A printer signal which becomes an image that can acquire appearance that is the same with the appearance 3 stimulation value is created from the appearance signals α, β and γ, and a hard copy is created.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention belongs to the technical field of image reproduction for reproducing an image created by computer graphics on a display or a hard copy.

[0002]

2. Description of the Related Art In computer graphics (hereinafter, referred to as CG) for displaying a three-dimensional object image on a screen such as a CRT, an object mapped to three-dimensional coordinates in a virtual space (simulation space) of the CG. The light reflected from the surface of the object in the direction of the observer is calculated by a ray tracing method (ray tracing method) or the like, and from this, the luminance of the image that the observer will observe is calculated, and this is displayed on the display device. In general, the information is converted into a two-dimensional image corresponding to the luminance information to be displayed. In addition, in order to obtain a more realistic image, various methods of displaying an image in consideration of multiple reflection between objects, scattering of an object surface, and the like have been performed.

On the other hand, in hard copies such as catalogs and pamphlets, it has been practiced to actually photograph an object as a photograph and reproduce the photograph as a hard copy. Here, it is a matter of course that a hard copy is also required to have an image with a higher sense of reality and with the features of the object accurately emphasized. In order to realize this, in hard copy, various processes such as adjustment of lighting at the time of photographing and gradation adjustment at the time of reproducing a photographed photograph in hard copy are performed.

In the former, the number of illumination light sources (from a single lamp to 2
A method of weakening or strengthening the shadow contrast of the target object by switching the lamps or multiple lightings of four lamps or the illumination angle is exemplified. Further, whether a light beam having a high directivity or a diffusing plate or the like is used to enhance the diffusivity is also used as a means for providing a similar effect. in this case,
Unless lighting is set in consideration of the characteristics of a film as a recording medium, an image that matches the intended expression intention cannot be created. For example, the range of the exposure amount that can be recorded on a reversal film is a logarithmic value of the light amount of 2 to 2.
It is about 2.5, and even if the lighting setting is out of this range, it cannot be reproduced as a hard copy even if the setting is preferable for a shooting scene. As an example,
Even if a strong auxiliary light is added to emphasize the shadows of white dresses etc. in portrait photography, the white part will be saturated when photographing with exposure optimized for the face and skin, and the white contrast will be reproduced well as a result Not done. Such deficiencies in shooting lighting are extremely difficult to correct in the image processing described later, so that a skilled photographer who can shoot in consideration of these characteristics is required.

In the latter, a photographed and developed film original (in many cases, a reversal film) is photoelectrically read by a scanner, and a digital image is processed in consideration of a color reproduction range and a dynamic range of a hard copy. Is done. For example, in typical four-color offset printing, the maximum reflection density is in the range of 1.8 to 2.2,
The maximum concentration of reversal film ranges from 3.2 to 4.0. Therefore, the operator of the scanner adjusts the compression ratio of the density range so that the shadow contrast of the subject, which is the purpose of expression in the scene, is optimized. The adjustment of these ratios depends not only on the purpose of expression of the printed matter as the final product, but also on the finished state of the film as the original when digitizing. In addition, a hard copy, a reversal film, and a display such as a CRT attached to a scanner have different image perception characteristics of an observer. For this reason, in general, even if the density conditions and the colorimetric values are reproduced so as to be the same, the state in which the image is perceived does not become the same. These perceptual properties have been studied for some time, for example, JCStev
ens et al. have reported the results (JCStevens, SSS
tevens; Opt. Soc. Amer. 53 (3), 1963). According to this, it is reported that the contrast perception characteristic changes about 1.3 times between when the surroundings are dark (for example, in a movie theater) and when outdoors in the daytime. Although this is an example relating to brightness, many reports have been made that the characteristics of color perception also change depending on ambient environmental conditions. Skilled scanner operators know this characteristic empirically.For example, when reproducing a summer coastal scene, perform processing such as finishing with higher contrast than usual and finishing lower with indoor still life etc. I have. By such processing, a more realistic hard copy reproduction can be obtained.

[0006] However, the lighting equipment that enables image reproduction according to the purpose of the hard copy is expensive, and as described above, by appropriately adjusting the lighting, an accurate photograph corresponding to the purpose of the hard copy can be obtained. Since photographing by a professional photographer who can shoot, it is inevitable that the cost will increase. Further, if the photographed photograph is inappropriate for the purpose of hard copy, it is impossible to cope with it by image processing or the like, and the photograph is often retaken.

[0007] As a method that is expected to perform such adjustment efficiently and expand the degree of freedom, a model of an object composed of three-dimensional image data is created by CG.
A virtual photographic scene is created by ray tracing to create two-dimensional image data, and if necessary, image processing is performed to accurately represent the features of the object corresponding to the purpose of the hard copy. Image data for reproducing a hard copy to create a hard copy. According to this method, expensive lighting equipment and a professional photographer are unnecessary, and even if the created hard copy is inappropriate, it is possible to re-create the image by image data processing. is there. Further, by having data of the object model separately from the scene, there is expected a merit that reuse of the object model, reconstruction of the layout, and the like are facilitated.

As described above, even when reproducing a CG image into a hard copy, it is natural that a high level of realism is required, and a reality equal to or higher than that of a hard copy created from a photograph is required. Various processes are performed to obtain an image having the image. However, at present, C
Even if a hard copy is created from G, an image with a high degree of realism is not necessarily obtained, unlike a hard copy created from a photograph.

In CG, the luminance observed from the observer direction is calculated by a ray tracing method or the like based on the surface shape data of the object mapped to the three-dimensional coordinates, and the calculated luminance is directly used as the C value.
It is reproduced on a display such as an RT. For example, the point of maximum brightness calculated in the model is set to the maximum value of the display, and the point where light does not reach is calculated as zero brightness. However, since there is a flare due to reflection of external light on the display (observation) surface and an offset due to dark current, the minimum luminance of the display luminance range does not become zero, and the luminance ratio is actually 1:10 to 1: The range is 100. In such a state, for example, when an object having a glossy surface is set as a model object, an ideal tone reproduction can be obtained only in a very small portion having high luminance due to specular reflection or the like. The tone is lost in most parts, resulting in an unnatural finish as a photographic image.

In conventional processes such as photographic processing and scanner processing, optimization is performed by setting the exposure on the camera side, and a photosensitive curve having an empirically created characteristic curve so as not to lose the gradation even in the highest luminance region. The material is used and processed through a scanner gradation conversion curve that is empirically set to be optimally reproduced in print. In addition, by changing the focal point of the camera lens or changing the focal position, it is possible to distinguish between those that emphasize details and those that are finished softly. However, it is extremely difficult to perform such processing after forming a two-dimensional digital image because there is no information on depth.

Further, as described above, when taking a photograph or a movie, the lighting and the like are adjusted in consideration of the observation environment of the finished image. Lighting is completely different between a film and a photograph used for a catalog or the like, and thus the finished image is also different. On the other hand, CG currently being performed is
Since the main purpose is ray tracing calculation for display on a CRT or the like, even if the image displayed on the display is reproduced in hard copy as it is, high realism cannot be obtained. It is thought that the inability to predict the finished state of the product also contributes to a lack of high realism.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. In reproducing a three-dimensional image created by computer graphics into a hard copy such as a printed matter, an object of the present invention is to solve the problem. A method of reproducing computer graphics that can obtain a hard copy in which an image having a sense of reality equal to or greater than that of a hard copy created using a photograph of the object is obtained, in other words, an object created by computer graphics An object of the present invention is to provide a computer graphics reproducing method capable of reproducing an image giving an appearance very close to a state actually observed by an observer in a virtual space of computer graphics in a hard copy.

[0013]

In order to achieve the above-mentioned object, the present invention provides a computer graphics system.
A computer graphics reproduction method for reproducing a three-dimensional image created in a three-dimensional coordinate space as a two-dimensional image, comprising: a virtual object information, a virtual light source information, and a virtual observer information in a virtual three-dimensional coordinate space of the computer graphics. Obtaining two-dimensional image data represented by appearance tristimulus values of a two-dimensional image projected onto an arbitrary plane in the virtual three-dimensional coordinate space, and obtaining two-dimensional image data represented by the obtained appearance tristimulus values: There is provided a computer graphics reproducing method characterized by generating image data for image reproduction, wherein an image reproduced by the image reproducing means has the same appearance as the appearance tristimulus value.

Further, the object information includes at least three-dimensional position information indicating a shape of the object and one-dimensional to multi-dimensional surface color information indicating a surface state of the object. , The three-dimensional position information of the light source, the information indicating the size of the light source, and the spectral luminance factor distribution information, and the observer information includes at least the three-dimensional position information of the observer and the visual information. Is preferred.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a computer graphics reproducing method according to the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 conceptually shows a computer graphics reproducing method according to the present invention. The computer graphics (hereinafter, referred to as CG) reproduction method of the present invention is a method of reproducing a CG image created in a virtual space (simulation space) of a CG into a hard copy, using three-dimensional coordinates (x, y, z) of the CG space. ), Information on the object 10 and the light source 12
From the information of the observer 14 and the information of the observer 14, an appearance tristimulus value, that is, an appearance signal α, β, γ indicating a two-dimensional image projected on a plane 16 arbitrarily created in the virtual space of the CG is obtained. From α, β, γ,
By creating a printer signal that becomes an image having the same appearance as the appearance three stimulus values, and creating a hard copy, the CG can be used to create a hard copy that is equivalent to or higher than a hard copy using a photograph as an original. It is possible to make a copy.

FIG. 4 conceptually shows a conventional method of reproducing a CG image into a hard copy. In the conventional reproduction method, basically, an image of an object 52 created in a virtual space of a CG having a point light source 50 (space indicated by a dotted line in FIG.
The CG image is converted into a hard copy by converting the image data of the image reproduced on the display 54 into image data corresponding to the image output by the printer P by reproducing the image as viewed by the observer 56 on the display 54 such as Has been reproduced. However, with this method, it is not possible to reproduce a highly realistic image on the hard copy due to a difference in the observation environment and conditions in the virtual space, the display 54, and the hard copy.

On the other hand, in the CG reproduction method of the present invention, a virtual light source 12 having a size is used in the virtual three-dimensional space of the CG by using the aforementioned object information, light source information and observer information. Irradiated object 10 (C
The reflected light of the object created in the three-dimensional space by G is projected onto an arbitrarily determined two-dimensional plane 16 and
An appearance signal, which is a two-dimensional image, which is image data when the virtual observer 14 in the same three-dimensional space views the two-dimensional image, that is, image data in which the light source 12, the observer 14 and the observation conditions are reflected. α, β, and γ. Then
For example, the appearance signals α, β, and γ of the CG are converted to obtain appearance signals α _h , β _h , and γ _h of a print image, that is, a CG reproduction image, and a printer signal (an image corresponding to the image output of the printer) is obtained. Data)
By creating a hard copy, it is possible to reproduce a hard-copy image with a high sense of reality that absorbs differences in light sources, viewing conditions, and the like, that is, an image with the same appearance as that of the CG.

The information of the light source 12 is information having a dimension of luminance. Basically, the wavelength λ and the declination θ of the light emitted from the light source 12 and the light source 1 in the three-dimensional space of the CG.
It is represented by a function S using the position x _s , y _s , and z _{s of 2} as parameters. S (λ, θ, x _s , y _s , z _s ) As shown in FIG. 1, the light source 12 is not a point light source but a light source having a certain size.

The information of the object 10 is information of the reflectance of light reflected in a certain direction at a certain point r of the object 10, and is basically composed of a wavelength λ, a declination θ, and r in a three-dimensional space.
Of the surface of the object 10 as parameters x _n , y _n , and z _n , and a function R having parameters as normals x _m , y _m , and z _m of the surface of the object 10. R (λ, θ, x _n , y _n , z _n , x _m , y _m , z _m ) The position x _n , y _n , z _n of the object in the three-dimensional space
There are no particular limitations on the method of capturing the image, and various known methods used in CG, such as a method of creating image data by a computer and a method of scanning two-dimensional information using a hologram, can be used. Further, the spectral reflectance versus angle direction with the object, if determined by a method such declination spectrophotometry, it is possible to calculate the normal direction X _m, Y _m, the spectral reflectance to Z _m.

Basically, the information of the observer 14 is the position x _i , y _i , z _{i of} the observer 14 in the three-dimensional space, the visual information of the observer 14, for example, the color matching function x (λ) of the human eye. ,
y (λ), z (λ), the adaptive white X _W of the observer 14,
Y _W , Z _W , and the adaptation luminance P of the observer 14. The adapted whites X _W , Y _W , and Z _W are colors that the observer 14 feels white in the space.
Of the stimulus value or chromaticity value. In addition, the adaptation luminance P
Is the luminance within which the observer 14 is familiar with the light source 12. For example, the brightness that the observer 14 is familiar with differs depending on whether the space (light source) is under the mid-summer sun or indoors. And

As described above, in the reproduction method of the present invention, the light emitted from the light source 12 and reflected on the object 10 is projected onto the plane 16 arbitrarily set in the three-dimensional space, thereby achieving the CG. A two-dimensional image is obtained from the three-dimensional image. The position of each point of the projected image (pixels) on this plane 16, the position x _p of the two-dimensional coordinate plane 16, shown in y _p.

In the CG reproduction method of the present invention, an appearance signal for reproducing an image created by CG into a two-dimensional image is calculated by using these. In the following example, first, light source information is used. Function S, function R as object information, observer position x _i , y _i , z _i , color matching function x (λ),
y (λ), z (λ) and the position x _p , y of the two-dimensional coordinates
_{Using p} , tristimulus values X, Y, and Z of the two-dimensional image projected on the plane 16 are calculated. The tristimulus values X, Y, Z are CI
What is necessary is just to calculate according to the calculation method of the tristimulus value of E (Commission Internationale I'Eclairage International Commission on Illumination). For example, as shown by the following formula, the function S and the color matching function (the visual Information) x (λ), y (λ), z
It can be calculated by integrating (λ).
As described above, the function S is integrated to correspond to the size of the light source 12. X = ∬x (λ) S · Rf (x i, y i, z i, x p, y
_{p) dsdλ Y = ∬y (λ} ) S · Rf (x i, y i, z i, x p, y
_{p) dsdλ Z = ∬z (λ} ) S · Rf (x i, y i, z i, x p, y
_{p) dsdλ} As shown in the above formula, X, Y, Z is, x _p, and is a function of y _p, i.e., X, Y, Z (Appearance signal described later α, β, γ) is a plan point of the projected two-dimensional images 16 (pixel) x _p, is the image data of y _p.

Next, the three stimulus values X, Y, and Z, the adaptive whites X _W , Y _W , and Z _W and the adaptive luminance P are used as parameters and are projected onto the plane 16 using predetermined functions A, B, and C. Data of a two-dimensional image viewed by the observer 14, that is, appearance signals (appearance tristimulus values) α, β, γ
Is calculated. α = A (X, Y, Z, X _W , Y _W , Z _W , P) β = B (X, Y, Z, X _W , Y _W , Z _W , P) γ = C (X, Y, P _{Z, X W, Y W,} Z W, P)

Various functions A, B, and C for calculating the appearance signals α, β, and γ are conceivable. For example, a method for calculating the colorimetric values L ^* a ^* b ^* conforming to the CIE is used. The following equation is exemplified.

(Equation 1)

In the above equation, l₀, A₀And b
₀Is based on the calculation method of CEI, ₀= 116, a
₀= 500, b₀= 200. Γ (P) is
This is a function obtained by using the response P as a parameter.
For example, as shown in FIG.
While changing by four digits to 100, γ (P) is 0.3-0.
It is a function that varies linearly between about five.

Next, the appearance signals α, β, γ of the two-dimensional image obtained in this manner are converted, and the appearance signals α _h , β _h , γ _{h of the} print image (ie, the hard copy reproduction image of the CG) are converted. , And a printer signal is obtained from the appearance signals α _h , β _h , and γ _h .

Appearance signals α _h , β of print image
_h and γ _h can be obtained basically in the same manner as the appearance signals α, β and γ of the two-dimensional image of the CG. That is, first, printer signals, for example, image data of three primary colors of C _i (cyan), M _i (magenta), Y _i (yellow) and K _i (black) (image density or an image obtained by digitizing the image density) Data), tristimulus values X _hi , Y _hi , and Z _hi of the image by the printer are obtained by a known method. X _hi = X _h (C _i , M _i , Y _i , K _i ) Y _hi = Y _h (C _i , M _i , Y _i , K _i ) Z _hi = Z _h (C _i , M _i , Y _i) , K _i ) Then, as parameters, the tristimulus values X _hi , Y _hi ,
Z _hi the observer adaptive white X _hW when observing the print, Y _hW, Z _hW and adaptation luminance P _h and functions using A, the B and C, of the printed image appearance signals alpha _h, beta _h, γ _h can be calculated. α _h = A (X _hi , Y _hi , Z _hi , X _hW , Y _hW , Z _hW ,
P _h ) β _h = B (X _hi , Y _hi , Z _hi , X _hW , Y _hW , Z _hW ,
P _h ) γ _h = C (X _hi , Y _hi , Z _hi , X _hW , Y _hW , Z _hW ,
P _h ) The functions A, B, and C are the same functions as the functions A, B, and C that calculated the appearance signals α, β, and γ of the object described above.

Therefore, the appearance signals α, β,
γ is converted to the appearance signal α _h , β of the print image
_h , γ _h , and the appearance signals α _h , β _h , γ _h
Calculates a printer signal (image data corresponding to the image output of the printer) by calculating the same from the above, and creates a hard copy using the printer signal, thereby absorbing a difference in light source, observation conditions, and the like, thereby realizing a high sense of reality. Images can be obtained.

The appearance signal α of the CG two-dimensional image,
From β and γ, appearance signals α _h and β of the print image
_h, the conversion to gamma _{h is, α = α h, β =} β h, so that gamma = gamma _h, both the 1: is a basic to convert 1.
For example, as shown by a (dashed line) in FIG.
A conversion table is prepared in which the relationship between α and α _h is a straight line having a slope of 1, and the conversion is performed using this conversion table. However, the appearance reproduction range (color reproduction range) of the CG often does not match the appearance reproduction range of the hard copy, and as shown by the dotted line in FIG. 3, the appearance reproduction of the CG is generally higher than that of the hard copy. Wide area. So, for example,
As shown by b (two-dot chain line) in FIG. 3, the appearance is compressed in accordance with the appearance reproduction area of the hard copy, such as adjustment of the inclination, and a conversion table is created in accordance with the appearance reproduction area of the hard copy. It is preferable to convert the appearance signals α, β, γ into appearance signals α _h , β _h , γ _{h of} the printer.

Here, when the object has luster, a pixel having a maximum luminance close to the direct reflection or a direct reflection may be observed depending on the observation direction. In such a case, if it is attempted to faithfully reproduce the tone from the highest luminance area, it is difficult to reproduce a good image due to the restriction of the reproduction range of the print or the display. In this case, in the costume space, assuming a completely diffuse reflector placed at an appropriate angle to the viewing direction, the X, Y, Z3 stimulus value adaptation white X _W, Y _W, and Z _W that Thus, the range of the appearance signal can be appropriately set. In this case, the highest luminance point has a higher luminance than the adaptive white color. In this region, by particularly increasing the compression of the appearance, it is possible to allocate an optimally reproducible range to the important subject. Further, by setting the adaptive white X _W , Y _W , and Z _W as follows, a more optimal appearance signal can be obtained. First, an average value Y _avg Y value of the two-dimensional image to be observed, and Y _W value of adaptive white 4-6 times the value of that value. Then, X, Y, Z of the light source
Set the X _W and Z _W values so that the values and ratios are the same. By doing so, it is possible to set a good appearance tristimulus value range for an average scene.

Further, preferably, an important object (so-called important subject) can be set in the three-dimensional coordinate space of the CG, and a conversion table in which the appearance is compressed in accordance therewith is prepared. Is used to convert the appearance signals α, β, γ into appearance signals α _h , β _h , γ _h of the print image. In order to reproduce a high-quality image, the difference in appearance between important subjects is important. Therefore, the appearance signals α _h , β _h , γ _h
It is preferable to secure the difference in the appearance of the important subject even after the conversion into the image is performed. Therefore, for example, if the important subject is the area c in the CG appearance reproduction area,
In this case, as shown by c (solid line) in FIG. 3, this area secures a slope of 1 and performs compression in the other areas to match the appearance reproduction area of the hard copy. Preferably, a conversion table is created.

Further, such compression is performed not only by using the conversion table but also by changing the light source information by adjusting the size, light amount, number, etc. of the virtual light source 12 in the CG three-dimensional coordinate space. Alternatively, both the compression of the conversion table and the adjustment of the light source 12 may be performed in combination. For example, by performing operations such as increasing the number of light sources and the size of the light source 12 and increasing the number thereof, the contrast of the CG image can be weakened as in the case of adding a reflex board and an auxiliary light in actual photographing. And, consequently, CG
Can be compressed. As an example, a good screen is created by automatically changing the lighting conditions such as the size of the light source, the diffusivity, the number of light sources, and the angle so that the histogram of the appearance signal is created and the distribution is averaged. It becomes possible. In addition, it is also possible to calculate the portion where the shape has changed but has little change as an appearance signal with respect to the initial state of a certain lighting by calculation, and it is also possible to relocate the light source position so that the portion is shaded is there.

In the CG reproduction method of the present invention, the obtained appearance signal (α, β, γ or α _h , β _h ,
Not only a printer signal is calculated from γ _h ), but also a printer signal may be converted into a display signal on a display such as a CRT, and an image reproduced in a hard copy may be displayed on the display. This makes it possible to perform various kinds of image information processing with reference to the display image, and to adjust the image reproduced in the hard copy on the display. Can be reproduced in hard copy.

Further, by storing the two-dimensional image data created by the method of the present invention, the reuse of the object model and the reconstruction of the layout are facilitated, and favorable results are obtained. In this case, it is most preferable to save and transmit the data in the following format in terms of both workability and efficiency. 1) Object shape data described by three-dimensional position coordinates and its surface material index 2) Surface material index file described by declination spectral reflectance information 3) Three-dimensional position coordinates and spectral luminance in each direction 4) Adaptive white and adaptive luminance data 5) Conversion function and parameters to appearance signal 6) Correspondence table between print signal and tristimulus value 7) Adaptive white and adaptive luminance data of print 8) Print Conversion functions and parameters to the appearance signal Among them, 1) to 5) have sufficient information as the original of the two-dimensional image, and by using 6) to 8) according to the desired print medium, Optimal image reproduction can be obtained for various print media. further,
By having data in such a configuration, editing and processing at the three-dimensional object level can be easily performed. For example, when an object a included in the image A is arranged in the image B, by editing the information 1) and 2) of the information a in addition to the image B, the user may feel uncomfortable in the shooting conditions of the image B. It is possible to combine images without any. Further, by using the data of 3) to 5) of the B image for the A image, processing such as adjusting the finish of the A image and the B image can be performed.

Although the computer graphics (CG) reproduction method of the present invention has been described in detail above, the present invention is not limited to the above example, and various changes and improvements can be made without departing from the gist of the present invention. It goes without saying that it may be performed.

[0037]

As described in detail above, according to the present invention, a three-dimensional image created by computer graphics is equivalent to or more than a hard copy created by using a photograph of an actual object. A hard copy that reproduces an object created by computer graphics in a virtual space of computer graphics and gives an appearance very close to the state actually seen by an observer in a virtual space of computer graphics is reproduced. be able to.

[Brief description of the drawings]

FIG. 1 is a computer graphics (CG) of the present invention.
It is a conceptual diagram for explaining a reproduction method.

FIG. 2 is a graph illustrating an example of an expression for calculating an appearance signal in the computer graphics reproduction method of the present invention.

FIG. 3 is an example of an appearance signal conversion table in the computer graphics reproduction method of the present invention.

FIG. 4 is a conceptual diagram showing a conventional computer graphics reproduction method.

[Explanation of symbols]

 10,52 object 12,50 light source 14,56 observer 16 plane 54 display

Claims (2)

[Claims] 1. A computer graphics reproducing method for reproducing a three-dimensional image created in a three-dimensional coordinate space by computer graphics as a two-dimensional image, comprising: virtual object information in a virtual three-dimensional coordinate space of computer graphics; From the virtual light source information and the virtual observer information, two-dimensional image data represented by appearance three-stimulus values of a two-dimensional image projected on an arbitrary plane in the virtual three-dimensional coordinate space is obtained. A computer graphics reproduction method, wherein image data for image reproduction is generated from a two-dimensional image data represented by a value, in which an image reproduced by an image reproduction means has the same appearance as the appearance tristimulus value. 2. The method according to claim 1, wherein the object information includes at least three-dimensional position information indicating a shape of the object and one or more information indicating a surface state of the object.
The observer has at least three-dimensional position information of the light source, information indicating the size of the light source, and spectral luminance factor distribution information. The computer graphics reproduction method according to claim 1, wherein the information includes at least three-dimensional position information of the observer and visual information.