US 7,453,460 B2Granted

System and method for generating pixel values for pixels in an image using strictly deterministic methodologies for generating sample points

AssigneeMental Images GmbH

InventorAlexander Keller

Life of this patent

Estimating the term…

Loading patent…

Abstract

A computer graphics system generates a pixel value for a pixel in an image, the pixel being representative of a point in a scene as recorded on an image plane of a simulated camera. The computer graphics system comprises a sample point generator and a function evaluator. The sample point generator is configured to generate a set of sample points representing at least one simulated element of the simulated camera, the sample points representing elements of, illustratively, for sample points on the image plane, during time intervals during which the shutter is open, and on the lens, a Hammersley sequence, and, for use in global illumination, a scrambled Halton sequence. The function evaluator is configured to generate at least one value representing an evaluation of a selected function at sample points generated by the sample point generator, those values corresponding to the pixel value.

Claims6

Dependent claims

A computer program product, comprising computer program instructions executable in a computer graphics system operable to generate one or more pixel values for a pixel in an image, the pixel being representative of a point in a scene as recorded on an image plane of a simulated camera, the image being displayable to a user via a display element in electrical communication with the computer, in response to display-controlling electrical signals generated by the computing element and communicated to the display element, the display-controlling electrical signals being generated by the computer based on the pixel values, the computer program instructions being executable by the computer graphics system to enable the computer graphics system to generate the pixel values for the image, the computer program product comprising a computer-readable physical medium having stored thereon:

A. computer-readable instructions executable by the computer graphics system to enable the computer graphics system to generate a set of sample points representing at least one simulated element of the simulated camera, the sample points representing elements of a Hammersley sequence, and
B. computer-readable instructions executable by the computer graphics system to enable the computer graphics system to generate at least one value representing an evaluation of a selected function at one of the sample points, the value generated corresponding to the pixel value;
wherein the generating of sample points comprises generating sample position points xi representing jittered sample point positions on a subpixel grid for at least one pixel on the image plane for use by the computer graphics system in evaluating the selected function;
and
wherein sample position points xi are generated in accordance with
x
i
=
⁢
(
s
x
+
Φ
2
⁡
(
k
)
,
s
y
+
Φ
2
⁡
(
j
)
)
=
⁢
(
s
x
+
σ
⁡
(
k
)
2
n
,
s
y
+
σ
⁡
(
j
)
2
n
)
where (sx,sy) are subpixel coordinates mapped onto strata coordinates
(j,k):=(sx mod 2n,sy mod 2n),
and instance number “i” corresponds to
i=j2n+σ(k)
where integer permutation
σ(k):=2nΦ2(k) for 0≦k<2n
for “n” a selected integer, and
Φδ(q)
is the radical inverse function of “q” in base “b”.

61 more elements

A. computer-readable instructions executable by the computer graphics system to enable the computer graphics system to generate a set of sample points representing at least one simulated element of the simulated camera, the sample points representing elements of a Hammersley sequence;
and
B. computer-readable instructions executable by the computer graphics system to enable the computer graphics system to generate at least one value representing an evaluation of a selected function at one of the sample points, the value generated corresponding to the pixel value;
wherein the generating of sample points comprises generating sample position points xi representing jittered sample point positions on a subpixel grid for at least one pixel on the image plane for use by the computer graphics system in evaluating the selected function,
wherein the simulated camera is to be provided with a shutter, and the computer-readable instructions executable by the computer graphics system to enable the computer graphics system to generate a set of sample points comprises computer-readable instructions executable by the computer graphics system to enable the computer graphics system to generate, for at least one sample point on a subpixel for at least one pixel on the image plane, sample time points ti,j representing “j” points in time during a time interval t0 to t0+T during which the shutter is to be open tot use by the computer graphics system in evaluating the selected function;
and
wherein the generating of sample points comprises generating the sample time points ti,j in accordance with
t
i
,
j
:=
t
0
+
(
Φ
3
⁡
(
i
)
⊕
j
N
T
)
·
T
where NT corresponds to a predetermined number of times at which sample time points ti,j are to be generated and
Φδ(q)
is the radical inverse function of “q ” in base “b|”.

29 more elements

A computer program product, comprising computer program instructions executable in a computer graphics system operable to generate one or more pixel values for a pixel in an image the pixel being representative of a point in a scene as recorded on an image plane of a simulated camera, the image being displayable to a user via a display element in electrical communication with the computer, in response to display-controlling electrical signals generated by the computing element and communicated to the display element, the display-controlling electrical signals being generated by the computer based on the pixel values, the computer program instructions being executable by the computer graphics system to enable the computer graphics system to generate the pixel values for the image, the computer program product comprising a computer-readable physical medium having stored thereon:

A. computer-readable instructions executable by the computer graphics system to enable the computer graphics system to generate a set of sample points representing at least one simulated element of the simulated camera, the sample points representing elements of a Hammersley sequence;
and
B. computer-readable instructions executable by the computer graphics system to enable the computer graphics system to generate at least one value representing an evaluation of a selected function at one of the sample points, the value generated corresponding to the pixel value;
wherein the generating of sample points comprises generating sample position points xi representing jittered sample point positions on a subpixel grid for at least one pixel on the image plane for use by the computer graphics system in evaluating the selected function;
wherein the simulated camera is to be provided with a shutter, and the generating of sample points comprises generating, for at least one sample point position on a subpixel for at least one pixel on the image plane, sample time points ti,j representing “j” points in time during a time interval t0 to t0+T during which the shutter is to be open for use by the computer graphics system in evaluating the selected function;
wherein the simulated camera is to be provided with a lens, and the generating of sample points comprises generating, for at least one sample point position and at least one sample time point, sample lens position points yi,j,k representing “k” points on the lens for use by the computer graphics system in evaluating the selected function;
and
wherein the generating of sample points comprises generating the sample lens points in accordance with
y
i
,
j
,
k
=
(
(
Φ
5
⁡
(
i
+
j
,
σ
5
)
⊕
k
N
6
)
,
(
Φ
7
⁡
(
i
+
j
,
σ
7
)
⊕
⁢
Φ
2
⁡
(
k
)
)
)
where
Φδ(q,σ)
is the scrambled radical inverse function of “q” in base“b” and “⊕” refers to addition modulo a predetermined value and instance number “i” corresponds to
i=j2n+σ(k)
where integer permutation
σ(k):=2nΦ2(k) for 0≦k<2n
for “n” a selected integer.

60 more elements

In a computer graphics system operable to generate a pixel value for a pixel in an image, the pixel being representative of a point in a scene as recorded on an image plane of a simulated camera, the image being displayable to a user via a display element in electrical communication with the computer, in response to display-controlling electrical signals generated by the computing element and communicated to the display element, the display-controlling electrical signals being generated by the computer based on the pixel values, the improvement comprising:

A. a sample point generator configured to generate a set of sample points representing at least one simulated element of the simulated camera, the sample points representing elements of a Hammerstey sequence;
and
B. a function evaluator configured to generate at least one value representing an evaluation of a selected function at one of the sample points generated by the sample point generator, the value generated by the function evaluator corresponding to the pixel value;
wherein the sample point generator is configured to generate sample position points xi representing jittered sample point positions on a subpixel grid for at least one pixel on the image plane for use by the function evaluator in evaluating the selected function;
wherein the simulated camera is to he provided with a shutter, and the sample point generator is configured to generate, for at least one sample point position on a subpixel for at least one pixel on the image plane, sample time points ti,j representing “j” points in time during a time interval t0 to t0+T during which the shutter is to be open for use by the function evaluator in evaluating the selected function;
and
wherein the sample point generator is configured to generate the sample time points ti,j in accordance with
t
i
,
j
:=
t
0
+
(
Φ
3
⁡
(
i
)
⊕
j
N
T
)
·
T
where NT corresponds to a predetermined number of times at which sample time points ti,j are to be generated and
Φδ(q)
is the radical inverse function of “q” in base “b|”.

29 more elements

A. a sample point generator configured to generate a set of sample points representing at least one simulated element of the simulated camera, the sample points representing elements Hammersley sequence;
and
B. a function evaluator configured to generate at least one value representing an evaluation of a selected function at one of the sample points generated by the sample point generator,the value generated by the function evaluator corresponding to the pixel value;
wherein the sample point generator is configured to generate sample position points xi representing jittered sample point positions on a subpixel grid for at least one pixel on the image plane for use by the function evaluator in evaluating the selected function;
wherein the simulated camera is to be provided with a shutter, and the sample point generator is con figured to generate, for at least one sample point position on a subpixel for at least one pixel on the image plane, sample time points ti,j representing “j” points in time during a time interval t0 to t0+T during which the shutter is to be open for use by the function evaluator in evaluating the selected function;
wherein the simulated camera is to be provided with a lens, and the sample point generator is configured to generate for at least one sample point position and at least one sample time point, sample lens position points Yi,j,K representing “k” points on the lens for use by the function evaluator in evaluating the selected function;
and
wherein the sample point generator is configured to generate the sample lens points in accordance with
y
i
,
j
,
k
=
(
(
Φ
5
⁡
(
i
+
j
,
σ
5
)
⊕
k
N
L
)
,
(
Φ
7
⁡
(
i
+
j
,
σ
7
)
⊕
Φ
2
⁡
(
k
)
)
)
where
Φδ(q,σ)
is the scrambled radical inverse function of “q” in base “b” and “⊕” refers to addition modulo a predetermined value and instance number “i” corresponds to
i=j2n+σ(k)
where integer permutation
σ(k):=2nΦ2(k) for 0≦k<2n
for “n” a selected integer.

59 more elements

Dependencies are inferred from the claim text.

Facts

Application: 11/548,124Filed 10 Oct 2006 · continuation
Priority: 19 Jun 2000
Published: US 2007/0273690 A129 Nov 2007
Granted: 18 Nov 2008
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

G06T 15/06
Three-dimensional [3D] image rendering: ray-tracing
G06T 15/506
Lighting effects: illumination models
G06T 15/55
Lighting effects: radiosity
G06T
Image data processing or generation, in general

Family

Application60/212,286Us provisional application · filed 19 Jun 2000
Application60/265,934Us provisional application · filed 1 Feb 2001
Application09/884,861Parent of this continuation · filed 19 Jun 2001
US 2007/0273690 A1Pre-grant publication · published 29 Nov 2007
US 7,227,547 B2Parent of this continuation
US 2005/0275660 A1Published application
US 7,453,460 B2This patent

From the US filing history. Foreign family members aren’t listed.