Perspective ruler display method

Abstract

When a user draws a picture on a virtual canvas using a drawing software, it is possible to more easily draw an illustration such as a photo taken by a fisheye lens. The disclosed technology provides a perspective ruler display method having a step of setting the angle of an angle OPW formed by a point O on the canvas, a point P placed on a straight line V passing through the point O and orthogonal to the plane of the canvas, and a point W existing in the three-dimensional space as [theta], setting the distance between the point O and the point P as 1, and setting the angle of the angle OPW as [theta], and setting the distance between the point O and the point P as [theta]; a straight line on the canvas or a graph present in the three-dimensional space is converted using a function f ([theta], k) that converts the coordinates of the point W into the coordinates of a point B on the canvas separated by a distance f ([theta], k) from a point O, and a curve having the same shape as a curve obtained by converting the straight line using the function f ([theta], k) is obtained. And displaying the perspective ruler with the obtained curve.

Description

TECHNICAL FIELD

[0001] The present application relates to a perspective ruler display method. BACKGROUND

[0002] Conventionally, when a perspective view of an illustration or the like is drawn using a drawing software, a perspective ruler based on the perspective method, i.e., the perspective method (referred to as "perspective" for short) is sometimes used.

[0003] When an illustration is drawn, the perspective ruler is used to draw an accurate perspective view based on the perspective method. One example of the method of using the perspective ruler is as follows.

[0004] In the case where a user draws an object, the perspective ruler is arranged in alignment with the object to be drawn. For example, in the case where the object is in the shape of a box, the perspective ruler is arranged along the shape of the box. A line of the perspective view can be drawn along the perspective ruler. In the case where the line is drawn, the user can draw along the guide line of the perspective ruler by using the perspective ruler, and thus, even if it is hand-drawing, a correct straight line can be drawn in accordance with the perspective method. By repeating the same procedure, an illustration in accordance with the perspective method can be drawn on a two-dimensional canvas.

[0005] In the composition of a general illustration, perspective in a straight line projection method called perspective projection is used, but when a more impressive effect is expressed, a special perspective called fish-eye perspective is sometimes adopted.

[0006] The fish-eye perspective is different from the perspective of the general perspective projection, and since a curved line needs to be drawn, it is difficult to draw an accurate line by hand work. Therefore, a ruler tool that assists the drawing of an object that expresses such a complex fish-eye lens is needed.

[0007] As a general fish-eye perspective ruler that has existed until now, a perspective ruler using a curved grid line is known.

[0008] There is a drawing software that provides a curved perspective ruler that can be used to draw an illustration having distortion like a photograph taken with a fish-eye lens. By using the curved perspective ruler, a user can draw an object that expresses the perspective method that is the same as the image of a photograph taken with a fish-eye lens. By using this software, it becomes easier to draw a perspective view taken with a fish-eye lens.

[0009] In addition, a non-patent literature that discloses a drawing method of fish-eye perspective exists (for example, refer to Non-Patent Literature 1). This literature discloses a general methodology when an illustration having distortion like a photograph taken with a camera using a fish-eye lens is drawn.

[0010] However, the existing fish-eye perspective ruler has the following characteristics.

[0011] A perspective ruler capable of depicting a curve obtained by photographing a line parallel to a coordinate axis of a virtual camera with a fisheye lens is known, but a perspective ruler capable of depicting lines having various directions is not provided.

[0012] In addition, there are various kinds of fisheye lenses, and the strength of deformation of the lenses differs from one another. However, the existing fisheye perspective ruler does not provide a function that enables a user to use a depiction operation having various deformations.

[0013] The fisheye perspective ruler is displayed in a grid pattern also at a position other than a position related to drawing, and thus a case where the user's drawing is hindered occurs.

[0014] Prior Art Documents

[0015] Non-Patent Documents

[0016] Non-Patent Document 1: https: / / oekaki-zukan.com / articles / 11818 SUMMARY

[0017] PROBLEMS TO BE SOLVED BY THE INVENTION

[0018] The disclosed technology aims to enable a user to more easily depict an illustration like a photograph taken with a fisheye lens when the user uses drawing software to depict a picture on a virtual canvas.

[0019] TECHNICAL MEANS FOR SOLVING THE PROBLEMS

[0020] The disclosed technology provides a perspective ruler display method in which a perspective ruler is placed on a planar canvas existing in a virtual three-dimensional space, and a computer displays the perspective ruler in accordance with an instruction from a user to depict a fisheye lens representation so as to depict a line on the canvas along the perspective ruler,

[0021] The perspective ruler display method has the following steps:

[0022] determining a function f(θ, k) for setting an angle of ∠OPW formed by a point O on the canvas, a point P placed on a straight line V passing through the point O and orthogonal to the plane of the canvas, and a point W existing in the three-dimensional space as θ, setting a distance between the point O and the point P as 1, and converting coordinates of the point W into coordinates of a point B on the canvas separated from the point O by a distance f(θ, k),

[0023] and the function f(θ, k) satisfies the following condition:

[0024] in a range of 0 ≦ θ < π / 2 in the range of θ for conversion,

[0025] 0 ≦ f(θ, k) ≦ R*tan(θ) is satisfied.

[0026]

[0027] and satisfies

[0028] In a case where a range of θ includes a region of π / 2 or more, in a range of π / 2 ≦ θ ≦ π in the range of θ,

[0029] satisfies f(θ, k) > 0,

[0030] and

[0031] The function f(θ, k) is used to transform a straight line on the canvas or a figure existing in the three-dimensional space, and a curve having the same shape as a curve obtained by transforming a straight line using the function f(θ, k) is obtained, and a perspective ruler having the obtained curve is displayed.

[0032] Here, k is a parameter indicating the strength of the distortion represented by the fisheye lens in the perspective ruler,

[0033] R is a parameter indicating the scaling of the entire perspective ruler centered on the point O.

[0034] In addition, in the disclosed technology, the point B can exist on a straight line on which a straight line connecting the point O and the point W is orthogonally projected on the plane of the canvas.

[0035] In addition, in the disclosed technology, the point W can be a point existing on the canvas, and the display of the perspective ruler can mean the display of a curve obtained by transforming a straight line on the canvas using the function f(θ, k).

[0036] In addition, in the disclosed technology, the point B can exist on a straight line connecting the point O and the point W.

[0037] In addition, in the disclosed technology, a curved surface G having an axisymmetric shape with the straight line V as an axis can be formed,

[0038] A point Q at which a straight line connecting the point P and the point W intersects the curved surface G, and a point D at which a straight line connecting a point S and the point Q intersects the canvas, the point S being a point S existing on the straight line V and being located on the opposite side of the point O with respect to the point P,

[0039] The value of k is proportional to the distance between the point P and the point S,

[0040] The value of the function f(θ, k) is proportional to the distance between the point O and the point D.

[0041] In addition, in the disclosed technology, it can also be that the curved surface G is formed in an axisymmetric shape with the straight line V as an axis,

[0042] A point at which a straight line connecting the point P and the point W intersects the curved surface G is set as a point Q, a point on the straight line connecting the point P and the point W is set as a point C, a value of an angle formed by the plane of the canvas and a vector OQ is set as a, and a value of an angle formed by the plane of the canvas and a vector OC is set as β,

[0043] The value of k is proportional to the value of β / α,

[0044] The value of the function f(θ, k) is proportional to the distance between the point O and the point C.

[0045] In addition, in the disclosed technology, it can also be that the function f(θ, k) coincides or approximates with R*tan(θ) when the intensity k of the deformation is a prescribed value.

[0046] In addition, in the disclosed technology, it can also be that, when the function f(θ, k) coincides or approximates with R*tan(θ) when the intensity k of the deformation is a prescribed value,

[0047] 2*R*tan(θ / 2) as a perspective projection,

[0048] R*θ as an equidistance projection,

[0049] 2*R*sin(θ / 2) as an equi-solid-angle projection, and

[0050] R*sin(θ) as an orthographic projection.

[0051] In addition, in the disclosed technology, it can also be that determining the function f(θ, k) includes the following steps:

[0052] In calculating the coordinates of the point B, different functions f(θ, k) are applied to the X coordinate of the point B and the Y coordinate of the point B on the coordinate axes, that is, the X axis and the Y axis, which are orthogonal to each other with the point O as the origin on the plane of the canvas, to calculate the coordinates of the point B on the canvas.

[0053] In addition, in the disclosed technology, displaying the perspective ruler includes the following steps:

[0054] The intensity k of the deformation and the scale factor R are set in such a way that the size of the function f(π / 2, k) is maintained at a constant value.

[0055] In addition, in the disclosed technology, the function f(0, k) can be defined by the following equation, f(0, k) = R * (k + 1) * sin(0) / (k + cos(0)),

[0056] Here, 0 < k < 2.

[0057] In addition, in the disclosed technology, the function f(0, k) can be defined by the following equation, f(0, k) = R * sin(0) / cos(0 - 0 * k / 2),

[0058] Here, 0 < k < 2.

[0059] In addition, the disclosed technology can provide a perspective ruler display method in which a perspective ruler is placed on a planar canvas, and a computer displays the perspective ruler in accordance with an instruction from a user to draw a fisheye lens representation on the canvas so as to draw a line along the perspective ruler,

[0060] The perspective ruler display method has the following steps:

[0061] A function g(r, k) is determined, the function g(r, k) being used to set a distance of a point O on the canvas from a point W existing on the canvas to r, and to convert coordinates of the point W into coordinates of a point B on the canvas separated from the point O by a distance g(r, k),

[0062] The g(r, k) satisfies:

[0063] 0 < g(r, k) < R * r,

[0064]

[0065] and

[0066] A curve is obtained by converting a straight line on the canvas using the function g(r, k), and a perspective ruler having the obtained curve is displayed,

[0067] Here, k is a parameter indicating a strength of a distortion of a fisheye lens representation in the perspective ruler,

[0068] R is a parameter indicating a zoom of an entirety of the perspective ruler centered on the point O. In addition, in the disclosed technology, the function g(r, k) can be defined by the following equation,

[0069] g(r, k) = R * (k + 1) * sin(tan -1 (r)) / (k + cos(tan -1 (r)),

[0070] Here, 0 < k < 2.

[0071] Further, in the disclosed technology, the function g(r, k) can be defined by the following equation,

[0072] g(r, k) = R * sin(tan -1 (r)) / cos(tan -1 (r) - tan -1 (r) * k / 2),

[0073] Here, 0≦k≦2.

[0074] Further, the disclosed technology provides a perspective ruler display method, the perspective ruler being a perspective ruler placed on a planar canvas existing in a virtual three-dimensional space, the computer displaying the perspective ruler in response to an instruction from a user to draw a fish-eye lens representation so as to draw a line on the canvas along the perspective ruler,

[0075] The perspective ruler display method has the following steps:

[0076] Based on an instruction from the user, determining a rule to convert a straight line on the canvas or a virtual straight line in the three-dimensional space into a curve on the canvas that is suitable for the fish-eye lens representation;

[0077] Generating the perspective ruler, the perspective ruler being determined by a curve based on the rule and a curve passing through a prescribed position on the canvas designated by the user;

[0078] Determining a position of a vanishing point at which curves of a plurality of the perspective rulers converge on a plane including the canvas so as to be recognized by the user; and

[0079] Displaying the perspective ruler on the canvas.

[0080] Further, in the disclosed technology, determining the rule can include the following steps:

[0081] In a case where the instruction from the user is to change an intensity of a distortion of the fish-eye lens representation, changing the rule in response to the change in the intensity of the distortion,

[0082] Generating the perspective ruler includes the following steps:

[0083] Changing the generated perspective ruler before the rule is changed to the perspective ruler determined by a curve, the curve being determined based on the changed rule and passing through the prescribed position on the canvas designated by the user before the rule is changed.

[0084] Further, in the disclosed technology, determining the rule can also be,

[0085] determining the rule based on at least one of an intensity of a distortion of a fisheye lens representation, a scale factor, and a position of an intersection of a central axis of a virtual lens of the fisheye lens representation and the canvas, specified by the user.

[0086] Additionally, in the disclosed technology, determining the rule can also include the steps of:

[0087] determining curves of two perspective vanes by drawing two curves on the canvas based on the user's indication;

[0088] taking an intersection of the two curves as a vanishing point; and

[0089] determining an intensity of a distortion of a fisheye lens representation based on at least a degree of bending of at least one of the two curves.

[0090] Additionally, in the disclosed technology, generating the perspective vanes can also include the steps of:

[0091] in a case where the user's indication is to change a tilt of the perspective vanes, in response to the change of the tilt, applying the rule to change the position of the vanishing point of the prescribed perspective vane.

[0092] Additionally, in the disclosed technology, generating the perspective vanes can also include the steps of:

[0093] in a case where the user's indication is to change the prescribed position, in response to the change of the prescribed position, applying the rule without changing the position of the vanishing point of the prescribed perspective vane, but changing the curve of the prescribed perspective vane through the changed prescribed position.

[0094] Additionally, in the disclosed technology, generating the perspective vanes can also include the steps of:

[0095] in a case where the user indicates to fix the position of the prescribed vanishing point, and without changing the prescribed position of the perspective vane converging to the prescribed vanishing point, the perspective vane cannot be changed.

[0096] Additionally, in the disclosed technology, generating the perspective vanes can also be, in a case where the intensity of the distortion is changed by the user, not moving the prescribed position.

[0097] Additionally, in the disclosed technology, generating the perspective vanes can also include the steps of:

[0098] in a case where the position of the vanishing point is changed according to the user's indication, changing the curve of the perspective vane.

[0099] Additionally, in the disclosed technology, displaying the perspective vanes can also include the steps of:

[0100] in a case where the display of the perspective ruler that has been displayed is changed,

[0101] the image drawn according to the user's instruction is changed along the plurality of perspective rulers respectively in accordance with the change of each of the plurality of perspective rulers.

[0102] In addition, in the disclosed technology, the display of the perspective ruler can also include the following steps:

[0103] in a case where the display of the perspective ruler that has been displayed is changed,

[0104] the image existing on the canvas is changed in accordance with the change of each of the plurality of perspective rulers.

[0105] In addition, the disclosed technology can also be a program that causes a computer to execute the perspective ruler display method.

[0106] Effects of Invention

[0107] The disclosed technology can provide an environment in which, when a user draws a picture on a virtual canvas using drawing software, an illustration like a photo taken with a fisheye lens can be drawn more easily. BRIEF DESCRIPTION OF DRAWINGS

[0108] Fig. 1 is a diagram that explains the outline of the disclosed technology. FIG. 1A is a diagram that shows an illustration drawn by a user using the disclosed technology. FIG. 1B shows a reference image that the user uses as a reference when drawing an illustration.

[0109] Fig. 2 is a diagram that explains the outline when a user draws an illustration using the disclosed technology.

[0110] FIG. 3 is a diagram that shows a state where a fisheye perspective ruler is set in cooperation with a reference image.

[0111] FIG. 4 is a diagram that shows a state where a curve 410 is drawn along the fisheye perspective ruler.

[0112] FIG. 5 is a diagram that shows a state where the display of the reference image is closed.

[0113] FIG. 6 is a diagram that shows one example of a function f(θ, k) used when generating a fisheye perspective ruler.

[0114] FIG. 7 is a diagram that shows one example in a case where θ exceeds 90° in the same method and function f(θ, k) as FIG. 6

[0115] FIG. 8 ​is a graph showing another example of the function f(θ, k) used to generate the fish-eye perspective ruler.

[0116] FIG. 9 is a graph showing an example of the case where θ exceeds 90° in the same method and function f(θ, k). FIG. 8

[0117] FIG. 10 is a graph showing an example of the case where the curved surface G is a curved surface other than a spherical surface.

[0118] Fig. 11 is a graph showing an example of the setting of the strength of the deformation and the determination of the vanishing point based on the user's instruction. FIG. 11A-11D is an example of a user interface through which the user can intuitively operate the strength of the deformation, the determination of the vanishing point, and the determination of two fish-eye perspective rulers.

[0119] Fig. 12 is a graph showing an example of the display of the fish-eye perspective ruler in the case where the user has changed the strength of the deformation. FIG. 12A is the display of the fish-eye perspective ruler before the strength of the deformation is changed. FIG. 12B is the display of the fish-eye perspective ruler after the strength of the deformation is changed.

[0120] Fig. 13 is a graph illustrating the movement of the vanishing point accompanying the change in the inclination of the fish-eye perspective ruler. FIG. 13A is the state before the inclination of the fish-eye perspective ruler is changed. FIG. 13B is the state after the inclination of the fish-eye perspective ruler is changed.

[0121] Fig. 14 is a graph showing an example of the addition of a fish-eye perspective ruler. In FIG. 14A-14C an example of the addition of one fish-eye perspective ruler is shown.

[0122] Fig. 15 is a graph showing the state when the prescribed position of the fish-eye perspective ruler is moved based on the user's instruction. FIG. 15A is the state before the prescribed position is moved. FIG. 15B is the state after the prescribed position is moved.

[0123] Fig. 16 shows an example of the display of the handle in the case where the user has given an instruction to fix the position of the vanishing point. FIG. 16A is the state before the user has given the instruction to fix the position of the vanishing point. FIG. 16B is the state after the user has given the instruction to fix the position of the vanishing point.

[0124] Fig. 17 is a graph showing the state transition in the case where the point O (lens center point O) at which the straight line V of the central axis of the virtual lens intersects the canvas is moved. FIG. 17A is the graph before the lens center point O is moved. FIG. 17B is the graph after the lens center point O is moved.​

[0125] Fig. 18 is a diagram showing state transition in a case where vanishing points are moved. FIG. 18A is a diagram before vanishing points are moved. FIG. 18B is a diagram after vanishing points are moved.

[0126] Fig. 19 is a diagram showing state transition in a case where intensity of deformation is changed. FIG. 19A is a diagram showing a state before intensity of deformation is changed. FIG. 19B is a diagram showing a state after intensity of deformation is changed.

[0127] Fig. 20 is a diagram showing state transition in a case where a scale factor R is changed. FIG. 20A is a diagram showing a state before scale factor R is changed. FIG. 20B is a diagram showing a state after scale factor R is changed.

[0128] Fig. 21 is a diagram showing change of display of fisheye perspective ruler. FIG. 21A is a diagram showing a state before intensity of deformation is changed. FIG. 21B is a diagram showing a state after intensity of deformation is changed.

[0129] Fig. 22 is a diagram showing a case where a curve that has been drawn along a fisheye perspective ruler is changed, along with change of display of the fisheye perspective ruler. FIG. 22A is a diagram showing a state before intensity of deformation is changed. FIG. 22B is a diagram showing a state after intensity of deformation is changed.

[0130] Fig. 23 is a diagram showing a case where an image of a canvas is changed, along with change of display of a fisheye perspective ruler. FIG. 23A is a diagram showing a state before intensity of deformation is changed. FIG. 23B is a diagram showing a state after intensity of deformation is changed.

[0131] Fig. 24 is a diagram showing a case where an image of a canvas is changed, along with change of display of a fisheye perspective ruler. FIG. 24A is a diagram showing a state before change. FIG. 24B is a diagram showing a state after change.

[0132] FIG. 25 is a flowchart of a process of generating a curve of a fisheye perspective ruler for drawing of fisheye lens representation.

[0133] FIG. 26 is a flowchart showing a process of using functions explained in FIG. 6 and FIG. 7 .

[0134] FIG. 27 is a flowchart showing a process of using functions explained in FIG. 8 andFIG. 9 a flowchart of the process of the function explained in the above.

[0135] FIG. 28 is a flowchart indicating a process of displaying a fish-eye perspective ruler on a canvas.

[0136] FIG. 29A and FIG. 29B is a flowchart indicating one example of a subroutine of the above step S2802 and step S2804.

[0137] FIG. 30 indicates a flow related to determination of a rule.

[0138] FIG. 31 indicates another flow related to determination of a rule.

[0139] FIG. 32 is a flowchart indicating an example of a process flow of generating a fish-eye perspective ruler.

[0140] FIG. 33 is a flowchart indicating another example of a process flow of generating a fish-eye perspective ruler.

[0141] FIG. 34 is a flowchart indicating an example of displaying a fish-eye perspective ruler.

[0142] FIG. 35 is a flowchart indicating another example of displaying a fish-eye perspective ruler.

[0143] FIG. 36 is a hardware configuration diagram of an embodiment.

[0144] FIG. 37 is a diagram indicating that a position of a point B is obtained from a position of a point W existing on a canvas without using θ.

[0145] FIG. 38 is a diagram indicating a user interface in which a plurality of fish-eye perspective rulers orthogonal to each other are easily set. DETAILED DESCRIPTION

[0146] Hereinafter, the disclosed technology will be described with reference to the drawings.

[0147] A perspective ruler is provided together with various functions when a user performs drawing using an input interface (for example, a pen, a mouse, a touch panel, a tablet, a pointing device, or the like) with respect to a virtual canvas on a plane. Note that, in this specification, sometimes explanation is omitted with respect to generally known functions among existing functions related to a perspective ruler.

[0148] In addition, in the present specification, a virtual three-dimensional space is sometimes mentioned. However, it should be noted that the virtual three-dimensional space is utilized for the purpose of easily understanding the present technology (the generation method of the perspective ruler, etc.), and the existence of the virtual three-dimensional space is not necessarily required when the user performs drawing using the present technology (the perspective ruler, etc.).

[0149] In addition, in the present specification, a case in which a line drawn by a straight line under a normal perspective projection is drawn by a curve represented by a fish-eye perspective is described as an example. However, the disclosed technology is not limited to the drawing of a line, and of course can be applied to other drawing methods such as a point, a circle, a rectangle, a range of coloring, and the like.

[0150] <Embodiment 1>

[0151] Fig. 1 is a diagram that explains an outline of the disclosed technology. FIG. 1A is a diagram that represents an illustration drawn by a user using the disclosed technology. FIG. 1B represents a reference image that the user uses as a reference when drawing the illustration.

[0152] FIG. 1A is a diagram in which an illustration 102A is drawn on a canvas 100. The illustration 102A becomes an image in which an object originally having a straight line has a distorted curve, like a photograph taken by a fish-eye lens. For example, a window 104A should have a window frame constituted by a straight line in a normal perspective projection method. However, the window 104A is distorted and curved like a photograph taken by a fish-eye lens. Such an illustration becomes a more impressive illustration than a normal perspective projection method.

[0153] FIG. 1B The window 104B existing in the reference image 102B illustrated also becomes a window that is curved in the same way, and the reference image 102B itself also becomes an image that intends to represent a fish-eye lens.

[0154] In the disclosed technology, a technology by which the illustration 102A that imitates the representation of a fish-eye lens can be easily drawn by a user is provided. Furthermore, when the user draws the illustration 102A, it is preferable that the reference image 102B can also be displayed as a draft on the canvas. Furthermore, it should be noted that the reference image 102B is not necessarily required when the user draws the illustration.

[0155] Alternatively, a case in which the reference image 102B exists only in the user's thought as a target image that the user intends to draw is assumed. Normally, the user has an image (an intended illustration) that the user will draw thereafter in his or her own thought. In order to materialize such a virtual image, the user configures a fish-eye perspective ruler in cooperation with the virtual image, and draws a curve along the configured fish-eye perspective ruler.

[0156] Fig. 2 is a diagram that explains an outline when a user draws an illustration using the disclosed technology. FIG. 2Ais a drawing in which a fish-eye perspective ruler and the like are displayed overlapping the canvas. FIG. 2B is a drawing in which a computer depicts a line of the outline of a building based on a user's instruction using the disclosed technology. FIG. 2C is a drawing in which a building and a landscape around the building are depicted. FIG. 2D is a drawing in which a completed illustration is represented.

[0157] FIG. 2A A depiction aid 200 including a fish-eye perspective ruler displayed overlapping a canvas is represented. The depiction aid 200 is preferably present in a layer different from a depiction layer in which an illustration is depicted.

[0158] In FIG. 2A , a sight line level 260 is a line also called a horizon line, and is a line that can be used when aligning a vanishing point of a perspective ruler with the horizon line. For example, it is known that in a projection method such as perspective projection, a plane parallel to the ground converges at the horizon line at an infinite distance. For example, it is known that a set of straight lines parallel to each other in three-dimensional space and a set of straight lines parallel to the ground converge at one vanishing point present on the sight line level 260 at an infinite distance, like a road wall of a road extending to an infinite distance. Such a sight line level 260 is used as a reference when setting a vanishing point of a fish-eye perspective ruler. An interface in which the vanishing point is attracted to the sight line level if the vanishing point is made close to the sight line level can also be provided.

[0159] In FIG. 2A , there are vanishing points 210, 220, 230. The vanishing point 220 and the vanishing point 230 are present on the line of the sight line level 260. Also, the fish-eye perspective rulers 222, 224, 226 converge at the vanishing point 220 present on the line of the sight line level 260. Likewise, the fish-eye perspective rulers 232, 234, 236 converge at the vanishing point 230 present on the line of the sight line level 260. The fish-eye perspective rulers 212, 214, 216 converge at the vanishing point 210 not present on the line of the sight line level 260. By using a fish-eye perspective ruler in which a vanishing point is present on the line of the sight line level 260, it is possible to easily depict a curve in which a straight line parallel to the ground is deformed based on fish-eye lens performance. Furthermore, a fish-eye perspective ruler having a vanishing point not present on the line of the sight line level 260 can be used when depicting with a curve in which a straight line not parallel to the ground is deformed based on fish-eye lens performance.

[0160] In FIG. 2A , a 180-degree circle 202 is depicted. The 180-degree circle corresponds to a direction of 90 degrees from the front of the camera in a virtual three-dimensional space. That is, the inside of the 180-degree circle corresponds to a region in front of the camera in the virtual three-dimensional space, and the outside of the 180-degree circle corresponds to a region behind the camera in the virtual three-dimensional space.

[0161] The lens circle refers to a circle formed by the end of the image of the captured image projected onto the capturing surface by the fisheye lens. The lens circle of the fisheye lens having a viewing angle of 180 degrees is the same as the 180-degree circle.

[0162] The fisheye perspective ruler having the vanishing point on the 180-degree circle 202 has another vanishing point (not shown) at a point on the 180-degree circle through the other vanishing point and the lens center point O.

[0163] The vanishing point can also be limited so as not to be moved by the user beyond the 180-degree circle.

[0164] In addition, the posture of the camera in the virtual three-dimensional space is not necessarily parallel to the ground. Therefore, it is preferable that the line of sight level 260 be freely set according to the purpose of the user's sketching.

[0165] Further, the lens circle can also be displayed on the canvas. In the case of the lens circle of the fisheye lens having a viewing angle exceeding 180 degrees, a pair of two vanishing points can be made to exist within the lens circle.

[0166] FIG. 2B A case where the outline of the building 280A is sketched along each fisheye perspective ruler based on the user's instruction is shown.

[0167] FIG. 2C A case where the sketch of the completed building 280B and the road around the building are sketched is shown. For example, in the case where the user sketches a curve, a line can also be sketched at the position of each fisheye perspective ruler. In addition, in the case where the user sketches a line at a place separated from the fisheye perspective ruler, an invisible fisheye perspective ruler at the position of the canvas indicated by the pointing device can also be selected, and a curve can be sketched along the selected fisheye perspective ruler based on the user's instruction. By doing so, since the number of displayed fisheye perspective rulers is reduced, it is possible to prevent the fisheye perspective rulers from causing an obstacle when the user sketches, and the computer can sketch a sketch having an appropriate fisheye lens representation based on the user's instruction.

[0168] FIG. 3 is a view showing a case where the fisheye perspective rulers are set in cooperation with the reference image.

[0169] The plurality of fisheye perspective rulers 342 converging at the vanishing point 340 and the plurality of fisheye perspective rulers 352 converging at the vanishing point 350 are fisheye perspective rulers along the edges of the table, the boundaries of the wall and the floor, and the horizontal frame of the window frame, which are considered to be straight lines parallel to the ground.

[0170] In the canvas 300, the plurality of fisheye perspective rulers 322 converging at the vanishing point 320 are fisheye perspective rulers along the legs of the table, the boundaries of the wall and the wall, and the vertical window frame, which are considered to be straight lines perpendicular to the ground.

[0171] In this way, by using the reference image, the user can easily set a plurality of fisheye perspective rulers.

[0172] FIG. 4 is a diagram showing a state in which the curve 410 is drawn along the fisheye perspective ruler.

[0173] By the user moving the pointing device on the canvas along the fisheye perspective ruler, the computer can draw the curve 410.

[0174] FIG. 5 is a diagram showing a state in which the display of the reference image is closed. The drawn curve 410 is displayed together with the fisheye perspective ruler. Further, the quadrangle 500 is a diagram conveniently described in order to show the position of the reference image.

[0175] FIG. 6 and FIG. 7 is a diagram showing one example of the function f(θ, k) used when the fisheye perspective ruler is generated. FIG. 6 is a diagram in the case of 0 ≦ θ < π / 2, FIG. 7 is a diagram in the case of π / 2 ≦ θ ≦ π. The angle of ∠OPW formed by the point O on the canvas 610, the point P placed on a straight line V passing through the point O and orthogonal to the plane of the canvas, and the point W existing in the three-dimensional space is set to θ, and the distance of the point O from the point P is set to 1. Further, the point S is placed, and the point S is a point existing on the straight line V, on the opposite side of the point O with respect to the point P, and at a distance of k from the point P.

[0176] In addition, the curved surface G is placed with the straight line V as the axis of symmetry. As an example of the curved surface G, a spherical surface with a radius of 1 centered on the point P can be given. Further, the curved surface G is not limited to such a spherical surface.

[0177] The point Q is set as a point at which the straight line connecting the point P and the point W intersects the curved surface G. The point D is set as a point at which the straight line connecting the point S and the point Q intersects the canvas 610. The distance from the point O to the point D is set to n.

[0178] In the case where the curved surface G is a spherical surface with a radius of 1 centered on the point P, the distance n is expressed as follows,

[0179] n = (k + 1) * sin(θ) / (k + cos(θ)) (Equation 1),

[0180] where 0 ≦ k ≦ ∞.

[0181] If the scale factor is set to R, the function f(θ, k) is expressed as follows,

[0182] f(θ, k) = R * (k + 1) * sin(θ) / (k + cos(θ)) (Equation 2).

[0183] Further, k is a parameter indicating the strength of the distortion in the fisheye lens representation, and the scale factor R is a parameter multiplying the scale factor to the entire conversion formula. f(0, k) is as follows, and is consistent or approximate to various projection methods according to the value of k.

[0184] k = 0: consistent with perspective (f(0, k) = R * tan(0)) (Formula 3-1),

[0185] k = 1: consistent with stereographic (f(0, k) = 2 * R * tan(0 / 2))

[0186] (Formula 3-2),

[0187] k = 1.8: approximate to equidistant (f(0, k) ≒ R * 0) (Formula 3-3),

[0188] k = 2.5: approximate to equisolid (f(0, k) ≒ 2 * R * sin(0 / 2)) (Formula 3-4),

[0189] k = ∞: consistent with stereographic (f(0, k) = R * sin(0)) (Formula 3-5).

[0190] In this way, by appropriately setting the distortion parameter k and the scale factor R, a fisheye perspective corresponding to fisheye lens representations of various properties can be defined.

[0191] Further, the radius of the 180-degree circle is the value of the function f(0, k) when 0 = π / 2, that is, f(π / 2, k).

[0192] The function f(0, k) has the following properties.

[0193] In the range of 0 ≦ 0 < π / 2 in the range of 0 for conversion,

[0194] 0 ≦ f(0, k) ≦ R * tan(0) (Formula 4) is satisfied,

[0195]

[0196] and f(0, k) > 0 (Formula 5-3) is satisfied,

[0197] In the case where the range of 0 includes a region of π / 2 or more, in the range of π / 2 ≦ 0 ≦ π in the range of 0,

[0198] f(0, k) > 0 (Formula 5-3) is satisfied,

[0199]

[0200] Equation 4 indicates that, compared to the transformation using perspective projection (and the same scaling), the coordinates of the transformed point move towards point O.

[0201] Equation 5-1 indicates that, compared to the transformation using perspective projection (and the same scaling), the portion corresponding to the result of the transformation using the function f(θ, k) shrinks in the radial direction centered at point O.

[0202] Equation 5-2 indicates that near point O, the scaling is roughly the same as that using perspective projection transformation (and the same scaling).

[0203] Based on the above conditions Equations 4, 5-1, and 5-2, it can be seen that near point O, the transformation using perspective projection is roughly the same, with contraction towards O. As the distance from point O increases, the degree of contraction in the radial direction centered on point O becomes stronger.

[0204] Furthermore, it can also be used as The function f(θ, k) is determined in a monotonically decreasing manner relative to θ. The transformation using the function f(θ, k) relative to the transformation using perspective projection (and the same scaling), the degree of contraction of the part corresponding to the result of the transformation becomes stronger (contracting in a smaller way) the further away from point O.

[0205] like FIG. 7 As shown, a fisheye perspective ruler can also be defined when θ exceeds π / 2 (90°). However, depending on the value of k, sometimes the value of f(θ, k) becomes infinite or does not satisfy Equation 5-4. Therefore, it is preferable to limit the range of θ to the range where the value of f(θ, k) does not become infinite and satisfies Equation 5-4.

[0206] Furthermore, if the value of k is set to -1 < k < 0, then the coil-like deformation can be represented. Point S is located on the same side as point O relative to point P.

[0207] The function f(θ, k) is used to transform a straight line on the canvas or a graphic existing in three-dimensional space to obtain a curve with the same shape as the curve obtained by transforming the straight line using the function f(θ, k), and then a fisheye perspective ruler with the obtained curve is displayed.

[0208] For a straight line L existing in three-dimensional space, there exists a graph F that satisfies the following conditions.

[0209] Condition: The graph F exists in three-dimensional space, and the curve obtained by transforming graph F using the function f(θ, k) is the same as the curve obtained by transforming line L using the function f(θ, k).

[0210] Using this, instead of converting the straight line L using the function f(θ, k), a curve of the fish-eye perspective ruler can be obtained by converting the figure F using the function f(θ, k).

[0211] Examples of such a figure F are shown below. Here, a plane including the point P and the straight line L is set as a plane E.

[0212] • an intersection line of the plane E and the curved surface G.

[0213] • a curve on the plane E.

[0214] • a planar figure on the plane E.

[0215] The above-described application using the figure F is also applicable to other examples of the function f(θ, k) described below.

[0216] In addition, in calculating the coordinates of the point B, the fish-eye perspective ruler can also be defined by the following method: by setting an orthogonal coordinate system (set as X and Y coordinates) with the point O as the origin on the plane of the canvas (not shown), applying a function f(θ, k) having different parameters on the X coordinate of the point B and the Y coordinate of the point B, and calculating the coordinates of the point B on the canvas to define the fish-eye perspective ruler.

[0217] By defining such a fish-eye perspective ruler, a fish-eye perspective ruler having different fish-eye lens representations in the X axis direction and the Y axis direction can be obtained.

[0218] The above-described application using different parameters on the X coordinate and the Y coordinate is also applicable to other examples of the function f(θ, k) described below.

[0219] FIG. 8 and FIG. 9 are graphs showing other examples of the function f(θ, k) used in generating a fish-eye perspective ruler. FIG. 8 is a graph in the case of 0≦θ<π / 2, FIG. 9 is a graph in the case of π / 2≦θ≦π.

[0220] The value of the angle of ∠OPW formed by the point O on the canvas 810, the point P placed on a straight line V passing through the point O and orthogonal to the plane of the canvas, and the point W existing in the three-dimensional space is set as θ.

[0221] The distance between the point O and the point P is set as 1.

[0222] A curved surface G of an axially symmetric shape with the straight line V as the axis is formed.

[0223] A point at which a straight line connecting the point P and the point W intersects the curved surface G is set as a point Q, and a value of an angle formed by the plane of the canvas 810 and a vector OQ is set as a. A point placed on the straight line connecting the point P and the point W is set as a point C, and a value of an angle formed by the plane of the canvas 810 and a vector OC is set as β.

[0224] k is defined as follows,

[0225] k = β / α (Equation 6).

[0226] A distance from the point O to the point C is set as m.

[0227] In a case where the curved surface G is a sphere with a radius of 1 centered at the point P, the distance m is expressed as follows,

[0228] m = sin(θ) / cos(θ - θ*k / 2) (Equation 7),

[0229] where 0 ≤ k ≤ 2.

[0230] If a scale factor is set as R, the function f(θ, k) is expressed as follows,

[0231] f(θ, k) = R*sin(θ) / cos(θ - θ*k / 2) (Equation 8).

[0232] Further, k is a parameter indicating the strength of distortion in fisheye lens representation, and the scale factor R is a parameter multiplying a scale to the entire conversion formula. f(θ, k) is as follows, and is consistent or approximate to various projection methods according to the value of k.

[0233] k = 0: consistent with perspective (f(θ, k) = R*tan(θ)),

[0234] k = 0.655: approximate to stereographic

[0235] k = 0.875: approximate to equidistant

[0236] k = 1: consistent with equisolid (f(θ, k) = 2*R*sin(θ / 2)), k = 2: consistent with stereographic (f(θ, k) = R*sin(θ)).

[0237] In this way, by appropriately setting the parameter k indicating the strength of distortion and the scale factor R, a fisheye perspective scale corresponding to fisheye lens representation of various properties can be defined.

[0238] The function f(θ, k) has the properties shown in Equation 4, Equations 5-1 to 5-4.

[0239] As shown in FIG. 9 , the fisheye perspective ruler can also be defined when θ exceeds π / 2 (90°). However, depending on the value of k, the value of f(θ, k) can become infinite or not satisfy Equation 5-4. Therefore, it is preferable to limit the range of θ to a range in which the value of f(θ, k) does not become infinite and satisfies Equation 5-4.

[0240] Further, if the value of k is set to k < 0, a line roll type deformation can be represented.

[0241] Further, regarding the application examples, the description is omitted since it has been explained.

[0242] By using the above functions, the fisheye perspective ruler can be defined.

[0243] In addition, the vanishing point can also be set to a point at which two fisheye perspective rulers intersect.

[0244] The horizon can also be a curve drawn using a function used when generating the fisheye perspective ruler. Further, the horizon can also be one of the fisheye perspective rulers, and when the user draws the horizon, the drawn line is attracted to the horizon, and the computer draws the horizon based on the user's operation.

[0245] FIG. 10 is a diagram showing an example in which the curved surface G is other than a spherical surface.

[0246] In FIG. 10 , the curved surface G 1010 has a curved surface in which a cone is inverted. In this case, the deformation of the area close to the point O is stronger than when the curved surface is a spherical surface. As such, by changing the shape of the curved surface G, various fisheye perspective rulers can be defined.

[0247] Fig. 11 is a diagram showing an example of the setting of the intensity of the deformation and the scale factor R and the determination of the vanishing point based on the user's instruction. FIG. 11A-11D Fig. 11 is a diagram showing an example of the setting of the intensity of the deformation and the scale factor R and the determination of the vanishing point based on the user's instruction.

[0248] In FIG. 11A , a straight line 1110 is drawn on the screen according to the user's instruction (for example, a straight line by dragging the start point D s 1120 and the end point D e 1124 of the mouse cursor).

[0249] In FIG. 11B , the vector determined by the start point and the end point of the next drag of the mouse cursor 1170 is set as the vector 1171.

[0250] Based on FIG. 11A the length L of the drag 1120 in d , FIG. 11B the length t of the component of the vector 1171 in the straight line 1110, it is possible to determine a plurality of parameters including the strength k of the deformation, the scale factor R, the lens center point O, and the radius Rp of the 180-degree circle.

[0251] Therefore, based on the determined parameters, the curve 1112 that bends the straight line 1110 by passing through the start point 1122 and the focus point 1124 is drawn (the line that becomes the basis of the fish-eye perspective ruler). At this time, with respect to the direction in which the straight line 1110 is bent, it is bent in a direction that coincides with the direction of the vector 1171 to obtain the curve 1112.

[0252] The strength of the deformation can be set to k = t / L d , for example. It can also be a different calculation formula, but it is preferable that k be 0 in the case of t = 0 and monotonically increase with respect to t. It is preferable that it become k = 1 in the case of t = L d .

[0253] The radius of the 180-degree circle can be Rp = L d 2 / t, for example. It can also be a different calculation formula, but it is preferable that it become infinite as t → 0 and monotonically decrease with respect to t in the case of t = L d , become L d .

[0254] The scale factor R can be obtained from the strength k of the deformation and the radius Rp of the 180-degree circle (for example, formula a-1, formula a-2 described later).

[0255] The lens center point O is on the perpendicular bisector of the line segment that connects the point D s and the point D e , and the distance of the straight line that passes through the point D s and the point D e from O can be set to -4(t - L d / 2) 2 / L d + L d . It is preferable that this distance be an upwardly convex function that becomes a minimum value of 0 in the case of t = 0, L d .

[0256] In FIG. 11CThe parameters have been decided in the center, so for example, by depicting the start point 1182 of the drag 1181 by the mouse cursor 1180 and determining the curve 1113 (the line that becomes the basis of the other fish-eye perspective scale) from the position of the end point 1184 of the drag 1181, it is possible to determine the intersection of the curve 1112 and the curve 1113 as the vanishing point 1130.

[0257] In FIG. 11D , it is preferable to delete the FIG. 11C curve 1112A and the curve 1113A in the center.

[0258] Further, it is also possible to appropriately depict the sight level in the manner of the vanishing point 1130 made by the production. In addition, it is also possible to depict a 180-degree circle according to the parameters.

[0259] As above, it is possible to display at least one vanishing point and two fish-eye perspective scales on the screen by a simple operation.

[0260] Further, the user is able to add two fish-eye perspective scales (not shown) with the intersection of the two curves as the vanishing point by depicting the two curves. In addition, in the case where the user has depicted a curve passing through the already-depicted vanishing point, it is also possible to add one fish-eye perspective scale (not shown) passing through the vanishing point.

[0261] Fig. 12 is a diagram showing an example of the migration of the display of the fish-eye perspective scale in the case where the user has changed the strength of the distortion. FIG. 12A The display of the fish-eye perspective scale before the strength of the distortion is changed is shown. FIG. 12B The display of the fish-eye perspective scale after the strength of the distortion is changed without changing the scale factor is shown.

[0262] FIG. 12A In the center, the sight level 1220A, the fish-eye perspective scales 1230A, 1240A are displayed in the 180-degree circle 1210A. There is a prescribed position 1222A indicated by the user on the line of the sight level. There is a prescribed position 1232A indicated by the user on the line of the fish-eye perspective scale 1230A. There is a prescribed position 1242A indicated by the user on the line of the fish-eye perspective scale 1240A. Also, the vanishing point 1250A exists on the line of the sight level 1220A.

[0263] In FIG. 12B , the strength of the distortion represented by the fish-eye lens is changed by the user, and the state in which the strength of the distortion is increased is shown.

[0264] Due to the increase in the strength of the distortion, changes occur in the following aspects compared to FIG. 12A in FIG. 12B .

[0265] (1) The size of the 180-degree circle 1210A is made smaller to become a 180-degree circle 1210B.

[0266] (2) The curvature of the fisheye perspective ruler 1230A, 1240A is increased and the length is made shorter to become a fisheye perspective ruler 1230B, 1240B, respectively.

[0267] Further, in the case of FIG. 12A and FIG. 12B , the strength k of the deformation is changed without changing the scale factor R, and thus the size of the 180-degree circle 1210A, 1210B is changed. It is also possible to change the strength k of the deformation in conjunction with the change of the scale factor R, without changing the size of the 180-degree circle.

[0268] Hereinafter, an example of how the strength of the deformation is changed in conjunction with the scale factor R when the radius of the 180-degree circle is kept as R p .

[0269] (1) In the case where the function f(θ, k) is defined by the equation 2,

[0270] when the radius of the 180-degree circle is set as R p , the following equation is derived from the equation 2,

[0271] R p = f(π / 2, k) = R*(k+1) / k.

[0272] According to the above equation, the following relationship is derived.

[0273] R = R p *k / (k+1) (equation a-1)

[0274]

[0275] By using this equation a = 1, the strength k of the deformation is changed in conjunction with the scale factor R in a state where the radius of the 180-degree circle is kept as a certain value R p .

[0276] (2) In the case where the function f(θ, k) is defined by the equation 8,

[0277] when the radius of the 180-degree circle is set as R p , the following equation is derived from the equation 8,

[0278] R p = f(π / 2, k) = R*cos(π*(2-k) / 4).

[0279] According to the above equation, the following relationship is derived.

[0280] R = R p / cos(π*(2-k) / 4) (equation a-2)​

[0281] The relationship.

[0282] By using the formula a=2 to link the deformation intensity k with the scaling factor R, it is possible to maintain the radius of the 180-degree circle at a constant value R. p Under the condition of [condition], the strength k of the deformation is changed.

[0283] Despite the aforementioned changes, the positions 1222A and 1222B on the horizontal line of sight remain (x0, y0) on the canvas and have not moved. Similarly, the positions 1232A and 1232B on the fisheye perspective ruler 1230A remain (x2, y2) on the canvas and have not moved. Likewise, the positions 1242A and 1242B on the fisheye perspective ruler 1240A remain (x1, y1) on the canvas and have not moved.

[0284] As described above, the specified positions can also be set so that they remain on the canvas even if the intensity of the deformation changes. For example, the fisheye perspective rulers set by the user to match the edges of a table can be set such that by pre-setting the aforementioned specified positions near the center of the table's edges, the shape of the fisheye perspective rulers changes while maintaining the user-specified positions, even if the intensity of the deformation changes. In this way, since the user can fix the specified positions in the fisheye perspective rulers, it is possible to make the fisheye perspective rulers follow the intended image position for referencing the image, and simultaneously change the tilt or curvature of the fisheye perspective rulers, making it easier to set fisheye perspective rulers with the user's desired shape.

[0285] The aforementioned advantages also apply to the specified positions set at eye level. By changing the intensity of the deformation, it is possible to prevent the eye level and the position and shape of the fisheye perspective ruler from changing to positions or shapes that the user does not desire.

[0286] Figure 13 illustrates the movement of the vanishing point as the inclination of the fisheye perspective ruler changes. FIG. 13A This indicates the state before the tilt of the fisheye perspective ruler was changed. FIG. 13B This indicates the state after changing the tilt of the fisheye perspective ruler.

[0287] exist FIG. 13AIn this design, the fisheye perspective ruler 1320A has a vanishing point 1370A and two handles 1324A for the user to adjust the tilt. Dragging either handle 1324A provides the user with the desired operation. Furthermore, the fisheye perspective ruler 1320A is set to a predetermined position 1322A. For example, when the user drags and moves one handle 1324A using the cursor 1370, the fisheye perspective ruler 1320A can rotate around the predetermined position 1322A in the direction of arrow 1350.

[0288] exist FIG. 13B In the diagram, the fisheye perspective ruler 1320A, indicated by the dashed line, rotates and bends along the direction of arrow 1350 according to the user's dragging operation, reaching the state of fisheye perspective ruler 1320B. Based on this rotation and bending change, the vanishing point 1370A moves to the position of vanishing point 1370B. Accompanying this movement of the vanishing point, the fisheye perspective ruler 1310A extends only by the amount indicated by arrow 1360 to reach vanishing point 1370B.

[0289] As described above, based on the user's instructions, the specified position 1322A can be fixed, while the position of the vanishing point can be moved by changing the tilt of the fisheye perspective ruler 1320A.

[0290] Figure 14 shows an example of adding a fisheye perspective ruler. FIG. 14A-14C The image shows an example of adding a fisheye perspective ruler.

[0291] exist FIG. 14A In the diagram, fisheye perspective rulers 1410 and 1420 share a vanishing point 1430. When the user presses the mouse button, for example, at cursor position 1450, line 1460A is displayed. While the user holds down the mouse button and drags cursor 1450, line 1460A rotates accordingly, for example, rotating to line B. Furthermore, in... FIG. 14A Although it displays straight lines 1460A and 1460B, it can also display curves.

[0292] exist FIG. 14B If the user continues to drag, the fisheye perspective ruler 1460C will snap to the vanishing point 1430.

[0293] exist FIG. 14C In the process, when the user ends the drag (releases the mouse button), the curve 1460D, which protrudes beyond the vanishing point 1430 of the fisheye perspective ruler 1460C, disappears. Through this operation, a new fisheye perspective ruler 1460C is generated that shares the existing vanishing point 1430.

[0294] Alternatively, it can be omitted. FIG. 14A The state is displayed when the user drags the mouse. FIG. 14BThe fisheye perspective ruler 1460C is generated by the cursor 1450. If the user releases the mouse button, the curve 1460D that protrudes from the vanishing point 1430 of the fisheye perspective ruler 1460C disappears. By this operation, a new fisheye perspective ruler 1460C that shares the already existing vanishing point 1430 can also be generated.

[0295] In addition, in the case where a plurality of vanishing points exist on the canvas, it can also be that, in the case where the user indicates the position of the vanishing point 1430 by the cursor 1450, the fisheye perspective ruler 1460C is generated that shares the indicated vanishing point 1430. FIG. 14B In the example shown in Fig. 14, according to the operation of the cursor 1450 indicated by the user, the fisheye perspective ruler 1460C is attracted to the vanishing point (not shown) that is closest to the position of the fisheye perspective ruler 1460C.

[0296] By the above, it is possible to easily add a new fisheye perspective ruler in such a way that it passes through a desired vanishing point.

[0297] Fig. 15 is a diagram showing the state when a prescribed position of a fisheye perspective ruler is moved based on an indication by a user. FIG. 15A The state before the prescribed position is moved is shown. FIG. 15B The state after the prescribed position is moved is shown.

[0298] In the example shown in Fig. 15, the fisheye perspective ruler 1520A has a vanishing point 1540. The user drags the prescribed position 1522A in the direction of the arrow 1530 by the mouse cursor 1550. FIG. 15A The state after the above dragging is shown in Fig. 16. The prescribed position is moved from the prescribed position 1522A to the prescribed position 1522B according to the dragging. Along with this movement, the curve of the fisheye perspective ruler is appropriately changed. In addition, the vanishing point 1540 and the other fisheye perspective ruler 1510 can not be changed.

[0299] FIG. 15B The state after the above dragging is shown in Fig. 16. The prescribed position is moved from the prescribed position 1522A to the prescribed position 1522B according to the dragging. Along with this movement, the curve of the fisheye perspective ruler is appropriately changed. In addition, the vanishing point 1540 and the other fisheye perspective ruler 1510 can not be changed.

[0300] Fig. 16 shows an example of the display of the handle in the case where the user gives an indication of the position of the fixed vanishing point. FIG. 16A The state before the user gives the indication of the position of the fixed vanishing point is shown. FIG. 16B The state after the user gives the indication of the position of the fixed vanishing point is shown.

[0301] In the example shown in Fig. 16, it is a state that allows the movement of the vanishing point 1610, so the four handles 1624 that change the inclination of the fisheye perspective ruler are displayed. In this case, the user can change the inclination of the fisheye perspective ruler by operating any one of the four handles 1624 with a mouse or the like. Along with this change, the vanishing point 1610 moves. FIG. 16A In the example shown in Fig. 16, it is a state that allows the movement of the vanishing point 1610, so the four handles 1624 that change the inclination of the fisheye perspective ruler are displayed. In this case, the user can change the inclination of the fisheye perspective ruler by operating any one of the four handles 1624 with a mouse or the like. Along with this change, the vanishing point 1610 moves.

[0302] FIG. 16B ​​In this case, if the state where movement of the vanishing point 1610 is not allowed is made, the four handles 1624 that change the tilt of the fisheye perspective ruler can also not be displayed. By so doing, the user cannot operate the tilt of the fisheye perspective ruler, and thus movement of the vanishing point 1610 corresponding to the operation can be prevented.

[0303] In addition, it can also be configured so that even if the user drags the vanishing point 1610 with the cursor, the vanishing point 1610 does not move. Further, it is preferable that even if the user moves the prescribed position, the position of the vanishing point does not move.

[0304] Further, with respect to the vanishing point whose movement is not allowed, it is preferable that even if the user changes the strength of the distortion, the vanishing point does not move. Further, in the case where the position of the vanishing point results in a failure due to the strength of the distortion or the scale factor R being changed such that the vanishing point exceeds the lens circle or the like, the vanishing point can be made to move.

[0305] Fig. 17 is a diagram that shows the state transition in the case where the point O (lens center point O) at which the straight line V of the central axis of the virtual lens intersects the canvas is moved. FIG. 17A is a diagram before the lens center point O is moved. FIG. 17B is a diagram after the lens center point O is moved.

[0306] FIG. 17A The position of the lens center point O (1710A) in FIG. 17B is moved to the lens center point O (1710B) in FIG. 17A The coordinates (x5, y5) of the prescribed position 1750A and the coordinates (x6, y6) of the prescribed position 1760A in FIG. 17B are also the coordinates (x5, y5) of the prescribed position 1750B and the coordinates (x6, y6) of the prescribed position 1760B, respectively, in Further, the 180-degree circle and the vanishing point move following the movement of the lens center point O. Along with this, the shapes of the fisheye perspective ruler 1752A and the fisheye perspective ruler 1762A of Fig. 17 change to the fisheye perspective ruler 1752B and the fisheye perspective ruler 1762B, respectively. It is preferable that the sight line levels 1790A, 1790B and the prescribed positions existing on the line of the sight line level move following the movement of the lens center point O.

[0307] By so doing, in the case where the reference image is displayed superimposed, the reference image and the prescribed position can be made not to shift.

[0308] Fig. 18 is a diagram that shows the state transition in the case where the vanishing point is moved. FIG. 18A is a diagram before the vanishing point is moved. FIG. 18B is a diagram after the vanishing point is moved.

[0309] In FIG. 18AIn this case, the vanishing point 1820A is moved in the direction of the arrow 1850. In FIG. 18B The position of the moved vanishing point 1820B is shown in FIG. 18B. In this case, FIG. 18A The coordinates (x7, y7) of the prescribed position 1870A and the coordinates (x8, y8) of the prescribed position 1880A in FIG. 18A are moved in the direction of the arrow 1850 in FIG. 18B The coordinates (x7, y7) of the prescribed position 1870B and the coordinates (x8, y8) of the prescribed position 1880B in FIG. 18B are not moved on the canvas. Accompanying the movement of the vanishing point 1820A to the vanishing point 1820B in FIG. 18, the shapes of the fisheye perspective ruler 1872A and the fisheye perspective ruler 1882A are changed to the fisheye perspective ruler 1872B and the fisheye perspective ruler 1882B, respectively.

[0310] As to the behavior when the vanishing point is dragged, for example, it can be set as follows. The behavior can be made different depending on whether the vanishing point is on the line of the horizon or not. In addition, even in the case where it is on the line of the horizon, the behavior can be made different depending on whether it is the first vanishing point or the vanishing point after the second vanishing point.

[0311] (1) The case where the vanishing point is the first vanishing point on the line of the horizon and the horizon is fixed:

[0312] • The position of the vanishing point is moved on the line of the horizon.

[0313] • The horizon is not changed even if the vanishing point is moved.

[0314] (2) The case where the vanishing point is the first vanishing point on the line of the horizon and the horizon is not fixed:

[0315] • The position of the vanishing point is not limited.

[0316] • The horizon is changed accompanying the movement of the vanishing point.

[0317] (3) The case where the vanishing point is the second or later vanishing point on the line of the horizon or the vanishing point not on the line of the horizon:

[0318] • The position of the vanishing point is not limited (but it can be set to the behavior of being attracted to the horizon).

[0319] • The horizon is not changed even if the vanishing point is moved.

[0320] By so doing, in the case where the reference image is superimposed and displayed, the reference image and the prescribed position can be made not to be deviated.

[0321] FIG. 19 is a diagram showing the state transition in the case where the strength of the deformation is changed.FIG. 19A is a diagram showing a state before the strength of deformation is changed. FIG. 19B is a diagram showing a state after the strength of deformation is changed.

[0322] In a case where the vanishing point 1950A is fixed, it is preferable to maintain the coordinates of the fixed vanishing point. In a case where no indication is given to fix any vanishing point, it is preferable to maintain all the coordinates of the prescribed positions.

[0323] In FIG. 19A , a case where no indication is given to fix the position of the vanishing point 1950A is shown. In this case, FIG. 19A the coordinates of the respective prescribed positions 1930A, 1940A in FIG. 19B are the same as the coordinates of the prescribed positions 1930B, 1940B in

[0324] On the contrary, in FIG. 19A , in a case where an indication is given to fix the coordinates of the vanishing point 1950A, it is preferable not to change the position of the vanishing point 1950B in FIG. 19B In this case, the coordinates of the respective prescribed positions 1930A, 1940A in FIG. 19B may not be the same as the coordinates of the prescribed positions 1930B, 1940B in

[0325] By so doing, in a case where the strength of deformation is changed, the user can select whether to fix the position of the vanishing point or to fix the prescribed positions.

[0326] Fig. 20 is a diagram showing state transition in a case where the scale factor R is changed. FIG. 20A is a diagram showing a state before the scale factor R is changed. FIG. 20B is a diagram showing a state after the scale factor R is changed.

[0327] In a case where the vanishing point 2022A is fixed, it is preferable to maintain the coordinates of the fixed vanishing point. In a case where no indication is given to fix any vanishing point, it is preferable to maintain all the coordinates of the prescribed positions.

[0328] In FIG. 20A , a case where no indication is given to fix the position of the vanishing point 2022A is shown. In this case, FIG. 20A the coordinates of the respective prescribed positions 2030A, 2040A in FIG. 20B are the same as the coordinates of the prescribed positions 2030B, 2040B in

[0329] On the contrary, in FIG. 20A , in a case where an indication is given to fix the coordinates of the vanishing point 2022A, it is preferable not to change the position of the vanishing point 2022B in FIG. 20Bthe position of the vanishing point 2022B in FIG. 20B. In this case, the coordinates of the prescribed positions 2030A, 2040A are respectively different from the coordinates of the prescribed positions 2030B, 2040B in FIG. 20B. FIG. 20B

[0330] By so doing, in the case where the scale factor R is changed, the user can select whether to fix the position of the vanishing point or to fix the prescribed positions.

[0331] FIG. 21 is a diagram showing a change in the display of the fish-eye perspective ruler. FIG. 21A is a diagram showing a state before the strength of the deformation is changed. FIG. 21B is a diagram showing a state after the strength of the deformation is changed.

[0332] As for the fish-eye perspective ruler 2150A in FIG. 20A, when an instruction to increase the strength of the deformation is given, the display is changed as in the fish-eye perspective ruler 2150B in FIG. 20B. As for the shapes of the other fish-eye perspective rulers and the line of sight level, by giving an instruction to increase the strength of the deformation, the display is changed as shown in FIGS. 21A and 21B similarly. FIG. 21A FIG. 21B As for the fish-eye perspective ruler 2150A in FIG. 20A, when an instruction to increase the strength of the deformation is given, the display is changed as in the fish-eye perspective ruler 2150B in FIG. 20B. As for the shapes of the other fish-eye perspective rulers and the line of sight level, by giving an instruction to increase the strength of the deformation, the display is changed as shown in FIGS. 21A and 21B similarly. FIG. 21A FIG. 21B

[0333] FIG. 22 is a diagram showing a case where, in conjunction with a change in the display of the fish-eye perspective ruler, a curve that has been drawn along the fish-eye perspective ruler is changed. FIG. 22A is a diagram showing a state before the strength of the deformation is changed. FIG. 22B is a diagram showing a state after the strength of the deformation is changed.

[0334] In the case where the display of the fish-eye perspective ruler (e.g., fish-eye perspective ruler 2250A) shown in FIG. 22A is changed to the fish-eye perspective ruler (e.g., fish-eye perspective ruler 2250B) shown in FIG. 22B, FIG. 22A FIG. 22B FIG. 22A FIG. 22B

[0335] By so doing, in the case where the fish-eye perspective ruler is changed, the user does not need to re-draw from the beginning either.

[0336] By so doing, in the case where the fish-eye perspective ruler is changed, the user does not need to re-draw from the beginning either.

[0337] By so doing, in the case where the fish-eye perspective ruler is changed, the user does not need to re-draw from the beginning either.

[0338] ​​​​​​​​Fig. 23 is a diagram showing a change in display accompanying the fisheye perspective ruler, in the case where the image referred to is changed, in addition to the curve already drawn along the fisheye perspective ruler being changed. FIG. 23A is a diagram showing the state before the strength of the change in deformation is changed. FIG. 23B is a diagram showing the state after the strength of the change in deformation is changed.

[0339] By so doing, in the case where the fisheye perspective ruler is changed, the user also does not need to start over and redraw, and since the image referred to as a reference image itself is also deformed, the user can easily refer to the details of the change in the reference image when continuing to draw in more detail, so the user can continue to draw more easily.

[0340] Fig. 24 is a diagram showing a change in display accompanying the fisheye perspective ruler, in the case where the image referred to is changed. FIG. 24A is a diagram showing the state before the change. FIG. 24B is a diagram showing the state after the change.

[0341] FIG. 24A the shape of either of the fisheye perspective rulers 2420A and 2430A in Fig. 24 is changed to FIG. 24B the fisheye perspective rulers 2420B and 2430B in Fig. 25, or FIG. 24A the position of the vanishing point 2450A in Fig. 24 is changed to FIG. 24B the position of the vanishing point 2450B in Fig. 25, and in conjunction therewith, the image referred to is also deformed. The image drawn (not shown) can also be changed in adaptation to this change.

[0342] As such, the fisheye perspective ruler is deformed in adaptation to a change in the curvature of the fisheye perspective ruler, a change in the position of the vanishing point, and the like based on the user's instruction, and the image drawn and / or the image referred to is also easily deformed in adaptation to this change.

[0343] <Embodiment 2>

[0344] FIG. 25 is a flowchart of the process of generating the curve of the fisheye perspective ruler for drawing for fisheye lens representation. The following describes each step of FIG. 25 .

[0345] [Step S2502] The function f(θ, k) is determined.

[0346] Here, regarding the function f(θ, k),

[0347] in the range of 0≦θ<π / 2 in the range of θ for conversion,

[0348] 0≦f(θ, k)≦R*tan(θ) (Equation 9) is satisfied,

[0349]

[0350] and satisfies

[0351] In a case where the range of θ includes a region of π / 2 or more, in the range of π / 2 ≦ θ ≦ π in the range of θ,

[0352] satisfies f(θ, k) > 0 (Equation 11),

[0353]

[0354] Equations 9, 10-1, and 10-2 have the same meanings as those already described with respect to Equations 4, 5-1, and 5-2.

[0355] With respect to Equation 11, in a case where θ exceeds π / 2 (90°), tan(θ) becomes a negative value in Equation 9, and therefore tan(θ) is omitted from the conditional expression.

[0356] Equation 12 indicates that, in a case where θ exceeds π / 2 (90°), the function is also a monotonically increasing function.

[0357] Using the function having the above conditions, for example, when a straight line on a canvas is converted, a curve close to a curve obtained by photographing a straight line with a fisheye lens can be obtained. By using this obtained curve for a fisheye perspective ruler, according to the perspective projection method, a line drawn with a straight line can be drawn using a curve close to an image photographed with a fisheye lens.

[0358] [Step S2504] A straight line on the canvas or a figure existing in the three-dimensional space is converted using the function f(θ, k), a curve having the same shape as a curve obtained by converting a straight line using the function f(θ, k) is obtained, and a fisheye perspective ruler having the obtained curve is displayed.

[0359] By this step S2504, a fisheye perspective ruler having a curve capable of drawing a fisheye lens representation can be displayed overlaid on a canvas.

[0360] By a user drawing on a canvas using this fisheye perspective ruler, a fisheye lens representation can be drawn.

[0361] Further, for example, if a trajectory of a circle is converted to generate a curve of a fisheye perspective ruler, a user can easily draw a curve photographed when a circle is photographed with a fisheye lens on a canvas using a fisheye perspective ruler having the curve.

[0362] FIG. 26 is a flowchart indicating a process using the functions described in FIG. 6 and FIG. 7 .

[0363] [Step S2602] This step indicates a function as a subroutine of Step S2502 of FIG. 25 .

[0364] [Step S2604] As a function f(θ, k), apply

[0365] f(θ, k) = R * (k + 1) * sin(θ) / (k + cos(θ)),

[0366] Here, 0 ≤ k ≤ ∞.

[0367] Regarding this function, use FIG. 6 and FIG. 7 are explained.

[0368] FIG. 27 is a flowchart indicating a process using the functions explained in FIG. 8 and FIG. 9 .

[0369] [Step S2702] This step indicates a function as a subroutine of Step S2502 of FIG. 25 .

[0370] [Step S2704] As a function f(θ, k), apply

[0371] f(θ, k) = R * sin(θ) / cos(θ - θ * k / 2),

[0372] Here, 0 ≤ k ≤ 2.

[0373] Regarding this function, use FIG. 8 and FIG. 9 are explained.

[0374] FIG. 28 is a flowchart indicating a process of displaying a fish-eye perspective ruler on a canvas.

[0375] Hereinafter, each step is explained.

[0376] [Step S2802] Based on an instruction of a user, determine a rule of converting a straight line on a canvas or a virtual straight line in a three-dimensional space into a curve on the canvas that is adapted to a fish-eye lens representation.

[0377] Regarding a specific example of the rule, since it has been explained, repeated explanation is avoided.

[0378] [Step S2804] Generate a fish-eye perspective ruler that is determined by a curve based on the rule and by a curve of a prescribed position on the canvas specified by the user.

[0379] [Step S2806] The position of a vanishing point at which the curves of the plurality of fish-eye perspective rulers converge is determined on the plane including the canvas, so that the user recognizes it.

[0380] [Step S2808] The fish-eye perspective rulers are displayed on the canvas.

[0381] By the above processing, the fish-eye perspective rulers can be displayed on the canvas.

[0382] FIG. 29A and FIG. 29B is a flowchart showing one example of a subroutine of the above step S2802 and step S2804.

[0383] [Step S2902] The flowchart after this step S2902 is a subroutine of step S2802.

[0384] [Step S2904] It is checked whether the user's instruction is a change in the strength of the deformation. In the case where the result of the check is affirmative (YES), it proceeds to step S2906. In the case where the result of the check is negative (NO), it returns.

[0385] [Step S2906] The rule is changed in response to the change in the strength of the deformation.

[0386] FIG. 29B The following processing flow shown below is executed after the above processing.

[0387] [Step S2910] The flowchart after this step S2910 is a subroutine of step S2804.

[0388] [Step S2912] The fish-eye perspective rulers generated before the change in the rule are changed to the fish-eye perspective rulers determined by the curves which are curves based on the changed rule and pass through the prescribed positions specified by the user before the change in the rule.

[0389] By the above processing, the curves of the fish-eye perspective rulers are appropriately changed in association with the change in the deformation.

[0390] FIG. 30 The flowchart showing the determination of the rule is shown.

[0391] [Step S3002] The flowchart after this step S3002 is a subroutine of step S2802.

[0392] [Step S3004] The rule is determined based on at least one of the strength of the deformation represented by the fish-eye lens, the scale factor, and the position of the virtual lens center point represented by the fish-eye lens, which are specified by the user.

[0393] The parameters not specified by the user can be determined in advance.

[0394] FIG. 31 represents other flows related to the determination of the rule.

[0395] [Step S3102] represents that the flow after this step S3102 is a subroutine of the step S2802.

[0396] [Step S3104] determines the curves of the two fish-eye perspective rulers by drawing two curves on the canvas based on the user's indication.

[0397] [Step S3106] takes the intersection of the two curves as the vanishing point.

[0398] [Step S3108]

[0399] determines the strength of the distortion of the fish-eye lens representation based on at least the degree of bending of at least one of the two curves.

[0400] FIG. 32 is a flowchart representing an example of the processing flow of generating a fish-eye perspective ruler.

[0401] [Step S3202] represents that the flow after this step S3202 is a subroutine of the step S2804.

[0402] [Step S3204] checks whether the user's indication is a change of the inclination of the prescribed fish-eye perspective ruler. In the case where the result of the check is affirmative (Yes), proceed to step S3206. In the case where the result of the check is negative (No), proceed to step S3208.

[0403] [Step S3206] changes the position of the vanishing point of the prescribed fish-eye perspective ruler and returns.

[0404] [Step S3208] checks whether the user's indication is a change of the prescribed position. In the case where the result of the check is affirmative (Yes), proceed to step S3210. In the case where the result of the check is negative (No), proceed to step S3212.

[0405] [Step S3210] does not change the position of the vanishing point, but changes the curve of the prescribed fish-eye perspective ruler through the changed prescribed position, and returns.

[0406] [Step S3212] checks whether the position of the prescribed vanishing point is fixed, and does not change the prescribed position of the fish-eye perspective ruler converging to the prescribed vanishing point. In the case where the result of the check is affirmative (Yes), proceed to step S3214. In the case where the result of the check is negative (No), return.

[0407] [Step S3214] sets to be unable to change the fish-eye perspective ruler and returns.

[0408] FIG. 33 is a flowchart showing another example of a processing flow of generating a fisheye perspective ruler.

[0409] [Step S3302] indicates that the flow after this step S3302 is a subroutine of step S2804.

[0410] [Step S3304] it is checked whether the strength of the deformation is changed by the user. In the case where the result of the check is affirmative (Yes), proceed to step S3306. In the case where the result of the check is negative (No), proceed to step S3308.

[0411] [Step S3306] change the curve of the fisheye perspective ruler without moving the prescribed position, and return. By not changing the prescribed position, it is possible to make the position of the fisheye perspective ruler at the prescribed position where the user is focusing not move.

[0412] [Step S3308] it is checked whether the position of the vanishing point is changed according to the user's instruction. In the case where the result of the check is affirmative (Yes), proceed to step S3310. In the case where the result of the check is negative (No), return.

[0413] [Step S3310] change the curve of the fisheye perspective ruler and return.

[0414] FIG. 34 is a flowchart showing an example of displaying a fisheye perspective ruler.

[0415] [Step S3402] indicates that the flow after this step S3402 is a subroutine of step S2808.

[0416] [Step S3404] it is checked whether the display of the fisheye perspective ruler that has been displayed is changed. In the case where the result of the check is affirmative (Yes), proceed to step S3406. In the case where the result of the check is negative (No), return.

[0417] [Step S3406] change the image drawn according to the user's instruction along the plurality of fisheye perspective rulers respectively in adaptation to the changes of the plurality of fisheye perspective rulers respectively.

[0418] FIG. 35 is a flowchart showing another example of displaying a fisheye perspective ruler.

[0419] [Step S3502] indicates that the flow after this step S3502 is a subroutine of step S2808.

[0420] [Step S3504] it is checked whether the display of the fisheye perspective ruler that has been displayed is changed. In the case where the result of the check is affirmative (Yes), proceed to step S3506. In the case where the result of the check is negative (No), return.

[0421] [Step S3506] The image existing on the canvas, which is used as a draft by the user, is changed in adaptation to the change of each of the plurality of fisheye perspective rulers.

[0422] Through this processing, the image used as a reference image by the user is changed in adaptation to the change of the fisheye perspective ruler.

[0423] FIG. 36 A hardware configuration diagram of an embodiment.

[0424] The hardware configuration of the embodiment has a CPU 4001, a ROM 4002 capable of storing a program and data of the embodiment, a RAM 4003, a network interface 4005, an input interface 4006, a display interface 4007, and an external memory interface 4008. These hardware are connected to each other through a bus 4004.

[0425] The network interface 4005 is connected to a network 4015. The network 4015 has a wired LAN, a wireless LAN, the Internet, a telephone network, and the like. The input interface 4006 is connected to an input section 4016. The display interface 4007 is connected to a display section 4017. The display section 4017 can be realized by a plurality of display devices. The external memory interface 4008 is connected to a storage medium 4018. The storage medium 4018 can be a RAM, a ROM, a CD-ROM, a DVD-ROM, a hard disk, a memory card, a USB memory, and the like.

[0426] [Modified example 1]

[0427] In a case where the point W exists on the canvas, by converting the variable by setting the distance of the point O and the point W as r, it is possible to perform equivalent expression using the distance r instead of the angle θ. The coordinates of the point W are converted into the coordinates of the point B on the canvas separated by the distance g(r, k) from the point O using the function g(r, k). The relationship of the distance r and the angle θ is expressed by the following formula.

[0428] r = tan(θ) (Formula 13).

[0429] Since the point W exists on the canvas, the range of θ is 0 ≦ θ < π / 2. The function g(r, k) equivalent to the function f(θ, k) is obtained by the following conversion.

[0430] g(r, k) = f(tan -1 (r), k) (Formula 14).

[0431] The conditional expression 0 ≦ f(θ, k) ≦ R*tan(θ) is replaced by the conditional expression 0 ≦ g(r, k) ≦ R*r.

[0432] The conditional expression is replaced by the conditional expression is replaced by the conditional expression Conditional expression Replaced with conditional expression

[0433] Therefore, the conditional expressions of equations 4, 5-1, and 5-2 are equivalent to the following equation.

[0434] 0≦g(r, k)≦R*r (Equation 15)

[0435]

[0436] in addition, The condition that θ is monotonically decreasing is replaced by This is in contrast to the condition that r is monotonically decreasing.

[0437] As FIG. 6 A variation of the embodiment shown will be described. By transforming Equation 2 using Equation 14, the following equation, which is equivalent to Equation 2, is obtained.

[0438] g(r, k) = R*(k+1)*sin(tan) -1 (r)) / (k+cos(tan -1 (r)))(Form 17).

[0439] As FIG. 8 A variation of the embodiment shown will be described. By transforming Equation 8 using Equation 14, the following equation, which is equivalent to Equation 8, is obtained.

[0440] g(r, k) = R * m = sin(tan -1 (r)) / cos(tan -1 (r)-tan -1 (r)*k / 2)

[0441] (Equation 18).

[0442] FIG. 37 This is a diagram showing how the position of point B is obtained without using θ, based on the position of point W existing on canvas 3710.

[0443] Using the function g(r, k) shown in Equation 17 or Equation 18, the coordinates of point W are converted to the coordinates of point B on the canvas 3710, which is separated from point O by a distance g(r, k). That is, the relationship between distance r and angle θ is given by g(r, k) = f(tanθ). -1 (r), k) represent.

[0444] <Variation Example 2>

[0445] FIG. 38 This is a diagram showing the user interface for easily setting up multiple orthogonal fisheye perspective rulers.

[0446] The plurality of fish-eye perspective rulers on the canvas that pass through the common vanishing point (e.g., fish-eye perspective rulers 3912 and 3914, and fish-eye perspective rulers 3922 and 3924) respectively correspond to sets of straight lines that are parallel to each other in three-dimensional space. It is also possible to set restrictions so that the set of straight lines in three-dimensional space that correspond to the fish-eye perspective rulers of one side on the canvas plane are orthogonal to the set of straight lines in three-dimensional space that correspond to the fish-eye perspective rulers of the other side.

[0447] FIG. 38 A specific example is shown. For example, consider a case in which a rectangle that is parallel to the ground in three-dimensional space is the object to be drawn, such as the upper surface of a table that has a rectangular shape. In this case, the deformed rectangle 3930 surrounded by the thick line is set to be the upper surface of the table, for example. The set of curves of the plurality of fish-eye perspective rulers 3912 and 3914 that pass through the vanishing point 3910 should be orthogonal to the set of curves of the plurality of fish-eye perspective rulers 3922 and 3924 that pass through the vanishing point 3920 in three-dimensional space. FIG. 36

[0448] Therefore, for example, it is possible to set so that if the user decides the position of the vanishing point 3910 on the line of the line of sight level 3902, the position of the vanishing point 3920 is automatically decided in a manner that satisfies the above-mentioned orthogonal condition in three-dimensional space.

[0449] Further, for example, it is also possible to set so that when the user moves the position of the vanishing point 3910 on the line of the line of sight level, the position of the vanishing point 3920 is automatically moved on the line of the line of sight level in conjunction therewith, satisfying the above-mentioned orthogonal condition in three-dimensional space.

[0450] By the above, it is possible to easily set so that the fish-eye perspective rulers that are orthogonal to each other can be easily set, and when the user changes the position of the fish-eye perspective ruler or the vanishing point of one side, the fish-eye perspective ruler of the other side can be easily maintained to be set to be orthogonal to each other in correspondence thereto.

[0451] To make such a setting, for example, it is possible to achieve by enabling the user to specify a pair of two vanishing points that have sets of fish-eye perspective rulers that are orthogonal to each other.

[0452] The order of the processes of the flowcharts illustrated can be changed as long as there is no contradiction. In addition, one of the processes illustrated can be executed multiple times at different timings as long as there is no contradiction. In addition, a plurality of processes can be executed simultaneously as long as there is no contradiction. In addition, not all of the steps are necessary, and a part of the steps can not exist or can not be executed as long as there is no contradiction.

[0453] ​The above aspects are also applicable to the configuration elements of the method of the protection scheme. That is, the order of the configuration elements can be changed as long as there is no contradiction. In addition, a plurality of configuration elements can be implemented at the same time as long as there is no contradiction. Furthermore, the implementation of these configuration elements also belongs to the technical scope of the protection scheme.

[0454] In addition, each step can be executed by an operating system or hardware. In addition, the program can be distributed in a state stored in a non-transitory medium.

[0455] The program and the method of implementing the above-described embodiments can be executed by a computer having a hardware configuration as shown in the drawings. That is, the program of the embodiments can also be implemented as a method of causing a computer to execute. ​

[0456] The program can also be stored in the storage medium 4018, the ROM 4002, or the RAM 4003.

[0457] Each embodiment can also be implemented as a device of hardware on which the program is installed.

[0458] The "fisheye perspective ruler" described in this specification is synonymous with the "perspective ruler" in the scope of protection and the drawings.

[0459] The scale factor R is one example of a parameter that represents the zoom of the entire fisheye perspective ruler.

[0460] Explanation of Reference Signs

[0461] 4004 bus

[0462] 4005 network interface

[0463] 4006 input interface

[0464] 4007 display interface

[0465] 4008 external storage interface

[0466] 4015 network

[0467] 4016 input section

[0468] 4017 display section

[0469] 4018 storage medium​

Claims

1. A perspective ruler display method, which places a perspective ruler on a planar canvas existing in a virtual three-dimensional space, and displays the perspective ruler so as to draw a line on the canvas along the perspective ruler, according to an instruction from a user to draw a fisheye lens representation, the perspective ruler display method having the steps of: determining a function f(θ, k) for setting an angle of ∠OPW formed by a point O on the canvas, a point P placed on a straight line V passing through the point O and orthogonal to a plane of the canvas, and a point W existing in the three-dimensional space as θ, setting a distance of the point O from the point P as 1, and converting coordinates of the point W into coordinates of a point B on the canvas separated from the point O by a distance f(θ, k), and the function f(θ, k) satisfies the following conditions: in a range of 0≦θ<π / 2 in a range of θ, 0≦f(θ, k)≦R*tan(θ) is satisfied, and satisfies in a case where a region of θ includes π / 2 or more, in a range of π / 2≦θ≦π in a range of θ, f(θ, k)>0 is satisfied, and converting a straight line on the canvas or a figure existing in the three-dimensional space using the function f(θ, k), obtaining a curve having the same shape as a curve obtained by converting a straight line using the function f(θ, k), and displaying a perspective ruler having the obtained curve; here, k is a parameter indicating a strength of distortion of a fisheye lens representation in the perspective ruler, R is a parameter indicating a scale of an entirety of the perspective ruler centered on the point O.

2. The perspective ruler display method according to claim 1, the point B exists on a straight line on which a straight line connecting the point O and the point W is orthogonally projected on a plane of the canvas.

3. The perspective ruler display method according to claim 1, the point W is a point existing on the canvas, and displaying the perspective ruler means displaying a curve obtained by converting a straight line on the canvas using the function f(θ, k).

4. The perspective ruler display method according to claim 3, the point B exists on a straight line connecting the point O and the point W.

5. The perspective ruler display method according to claim 1, a curved surface G having an axial symmetry with the straight line V as an axis is formed, a point Q at which a straight line connecting the point P and the point W intersects the curved surface G is set, a point D at which a straight line connecting a point S existing on the straight line V and located on an opposite side of the point O from the point P intersects the canvas is set, a value of the k is proportional to a distance of the point P from the point S, a value of the function f(θ, k) is proportional to a distance of the point O from the point D.

6. The perspective ruler display method according to claim 1, a curved surface G having an axial symmetry with the straight line V as an axis is formed, A point at which a straight line connecting the point P and the point W intersects the curved surface G is set as a point Q, a point placed on the straight line connecting the point P and the point W is set as a point C, a value of an angle formed by the plane of the canvas and a vector OQ is set as α, a value of an angle formed by the plane of the canvas and a vector OC is set as β, The value of k is proportional to the value of β / α, The value of the function f(θ, k) is proportional to the distance of the point O and the point C.

7. The perspective ruler display method according to claim 1, The function f(θ, k) coincides or approximates to R*tan(θ) when the intensity k of the deformation is a prescribed value.

8. The perspective ruler display method according to claim 1, The function f(θ, k) coincides or approximates to at least one of 2*R*tan(θ / 2) as a stereographic projection, R*θ as an equidistance projection, 2*R*sin(θ / 2) as an equistereographic projection, and R*sin(θ) as an orthographic projection when the intensity k of the deformation is a prescribed value.

9. The perspective ruler display method according to claim 1, Determining the function f(θ, k) includes the steps of: When the coordinates of the point B are found, different functions f(θ, k) are applied to the X coordinate of the point B and the Y coordinate of the point B on the coordinate axes X and Y, which are orthogonal to each other with the point O as the origin on the plane of the canvas, to find the coordinates of the point B on the canvas.

10. The perspective ruler display method according to claim 1, Displaying the perspective ruler includes the steps of: The intensity k of the deformation and the scale factor R are set in such a manner that the magnitude of the function f(π / 2, k) is maintained at a constant value.

11. The perspective ruler display method according to claim 1, The function f(θ, k) is defined by the following equation, f(θ, k) = R*(k + 1)*sin(θ) / (k + cos(θ)), Here, 0≦k≦∞.

12. The perspective ruler display method according to claim 1, The function f(θ, k) is defined by the following equation, f(θ, k) = R*sin(θ) / cos(θ - θ*k / 2), Here, 0≦k≦2.

13. A perspective ruler display method in which a perspective ruler is placed on a canvas in a planar shape, and a computer displays the perspective ruler in accordance with an instruction from a user to draw a fish-eye lens representation along the perspective ruler to draw a line on the canvas, The perspective ruler display method has the steps of: Determining a function g(r, k) for converting the coordinates of a point W existing on the canvas into the coordinates of a point B on the canvas separated from the point O by a distance g(r, k) with the distance of the point O and the point W on the canvas being r, The g(r, k) satisfies: 0≦g(r, k)≦R*r, A curve is obtained by converting a straight line on the canvas using the function g(r, k), and a perspective ruler having the obtained curve is displayed; Here, k is a parameter indicating the intensity of the deformation of the fish-eye lens representation in the perspective ruler, R is a parameter indicating the scaling of the entire perspective ruler with the point O as the center. ​ and ​ ​ ​ 14. The vanishing point display method according to Claim 13, the function g(r, k) is defined by the following equation, g(r, k) = R * (k + 1) * sin(tan -1 (r)) / (k + cos(tan -1 (r)), here, 0 < k < ∞.

15. The vanishing point display method according to Claim 13, the function g(r, k) is defined by the following equation, g(r, k) = R * sin(tan -1 (r)) / cos(tan -1 (r) - tan -1 (r) * k / 2), here, 0 < k < 2.

16. A program, which causes a computer to execute the vanishing point display method according to any one of Claims 1 to 15.

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