Projection system, projector apparatus, imaging apparatus, and projection method

Patent metadata

Field	Value
Publication number	US-9964839-B2
Application number	US-201715720167-A
Country	US
Kind code	B2
Filing date	Sep 29, 2017
Priority date	Mar 31, 2015
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

Even when a high-performance imaging apparatus is not used, luminance unevenness and color unevenness of an image (video) projected on a projection plane by the projection type projector apparatus are appropriately reduced. Using a coefficient Br (0≤Br≤1) set by a coefficient setting unit, the projection system obtains, based on the gamma characteristic of the entire system of the projection system, a target image for reducing the number of pixels saturated when the image is projected. Then, the projection system performs correction processing using the obtained target image based on the gamma characteristic of the entire system of the projection system and a white value. This reduces the number of saturated pixels of the projected image in the projection system. Furthermore, even in a case or similar cases when a captured image obtained by capturing a projected image has a bad S/N ratio, image projection processing that does not cause a user discomfort in viewing the projected image (or captured image) is achieved.

First claim

What is claimed is:

1. A projection system for projecting an image obtained by performing a predetermined process on an input image, the projection system comprising:
projection circuitry configured to project an image onto a projection target;
imaging circuitry configured to obtain an image projected by the projection circuitry as a captured image;
gamma characteristic obtaining circuitry configured to obtain a gamma characteristic determined by an optical system of the projection circuitry and an optical system of the imaging circuitry;
pixel mapping circuitry configured to obtain pixel mapping data based on a projection image, which is an image projected from the projection circuitry, and a captured image obtained by the imaging circuitry, the pixel mapping data being data for pixel-to-pixel correspondence between pixels in the captured image and pixels in the projected image;
response characteristic obtaining circuitry configured to obtain, for each pixel, a white value that is a pixel value of a captured image obtained by capturing a W100%-image projected by the projection circuitry using the imaging circuitry and a black value that is a pixel value of a captured image obtained by capturing a W0%-image projected by the projection circuitry using the imaging circuitry, and obtain a representative white value that is a representative value derived from the obtained white value and a representative black value that is a representative value derived from the obtained black value;
coefficient setting circuitry configured to set a first coefficient;
target image obtaining circuitry configured to obtain a target image from the input image based on the gamma characteristic obtained by the gamma characteristic obtaining circuitry and the first coefficient; and
correction circuitry configured to perform correction processing on the target image based on the gamma characteristic obtained by the gamma characteristic obtaining circuitry, the white value, and the black value to obtain a corrected image, and wherein
the target image obtaining circuitry obtains the target image such that saturated pixels decrease in an image that is predicted to be captured by the imaging circuitry when the projection circuitry projects the corrected image.

2. The projection system according to claim 1 , wherein
assuming that the input image and the target image are N-bit image (N is a natural number), a pixel value Px of the input image and a pixel value Px of the target image satisfy 0≤Px≤2^N−1, the first coefficient is Br satisfying 0≤Br≤1, a pixel value at coordinates (u, v) in the input image is I u, v , a pixel value at coordinates (u, v) in the target image is T u, v , a gamma value defining the gamma characteristic is γ, the representative white value is Wave, and the representative black value is Bmax, the target image obtaining circuitry obtains the target image by obtaining the pixel value T u, v in the target image through processing corresponding to one of the following formulae:

T

u
,
v

=

Br
×

(

W
ave

-

B

ma
⁢

⁢
x

)

×

(

I

u
,
v

2
N

-
1

)

γ

+

B

ma
⁢

⁢
x

(
cl2a
)

T

u
,
v

=

(

W
ave

-

B

ma
⁢

⁢
x

)

×

(

Br
×

I

u
,
v

2
N

-
1

)

γ

+

B

ma

Assignees

• Megachips Corp
• Univ Electro Communications

Inventors

• Hashimoto Naoki
• Kohari Chiharu
• Haraguchi Yuki
• Shingu Fumiya
• Tanaka Motoyasu

Classifications

• H04N9/3182

  Colour adjustment, e.g. white balance, shading or gamut (white balance per se H04N9/73; control of amplitude of colour signals H04N9/68; colour control circuits for displays in general G09G5/02, G09G3/2003, G09G3/3607) · CPC title

• G06T3/005

  Physics · mapped topic

• G03B37/04

  with cameras or projectors providing touching or overlapping fields of view · CPC title

• H04N9/3176

  wherein the projection device is incorporated in a camera (details of cameras adapted for combination with a projector not peculiar to the presence of an electronic spatial light modulator G03B17/54) · CPC title

• H04N9/3147

  Multi-projection systems (video walls G06F3/1446) · CPC title