Perceptual luminance nonlinearity-based image data exchange across different display capabilities

Patent metadata

Field	Value
Publication number	US-9685139-B2
Application number	US-201615283223-A
Country	US
Kind code	B2
Filing date	Sep 30, 2016
Priority date	Dec 6, 2011
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

A handheld imaging device has a data receiver that is configured to receive reference encoded image data. The data includes reference code values, which are encoded by an external coding system. The reference code values represent reference gray levels, which are being selected using a reference grayscale display function that is based on perceptual non-linearity of human vision adapted at different light levels to spatial frequencies. The imaging device also has a data converter that is configured to access a code mapping between the reference code values and device-specific code values of the imaging device. The device-specific code values are configured to produce gray levels that are specific to the imaging device. Based on the code mapping, the data converter is configured to transcode the reference encoded image data into device-specific image data, which is encoded with the device-specific code values.

First claim

What is claimed is:

1. An apparatus comprising:
a non-transitory storage media; and
a bitstream stored on the non-transitory storage media, the bitstream comprising an image and metadata,
wherein:
(i) the metadata includes a minimum luminance value and a maximum luminance value,
(ii) the image is encoded with digital code values D that represent a normalized luminance Y based at least in part on a functional model of

Y
=

(

max
⁡

[

(

V

1
⁢

/

⁢
m

-

c
1

)

,
0

]

c
2

-

c
3

⁢

V

1
⁢

/

⁢
m

)

1
⁢

/

⁢
n

,

(iii) parameters n, m, c 1 , c 2 , and c 3 are predetermined values, and
(iv) normalized value V of the digital code values D is 0≦V≦1.

2. The apparatus of claim 1 , wherein a relationship between the normalized value V and the digital code value D is provided by the function:

V
=

D
-

4
·

2

b
-
10

1015
·

2

b
-
10

wherein b is a bit depth corresponding to a number of bits used to represent the digital code value D.

3. The apparatus of claim 2 , wherein the bit depth b is 10 bits.

4. The apparatus of claim 2 , wherein the bit depth b is 12 bits.

5. The apparatus of claim 2 , wherein the digital code value D represents a sampled value of a component of the image data comprised in a serial digital interface signal.

6. The apparatus of claim 1 , wherein:

n
=

2610
4096

×

1
4

≃
0.1593017578125

;

m
=

2523
4096

×
128

≃
78.84375

;

c
1

=

c
3

-

c
2

+
1

=

3424
4096

≃
0.8359375

;

c
2

=

2413
4096

×
32

≃
18.8515625

;
and

c
3

=

2392
4096

×
32

≃

18.6875
.

7. An apparatus comprising:
a non-transitory storage media; and
a bitstream stored on the non-transitory storage media, the bitstream comprising an image and metadata,
wherein:
(i) the metadata includes a minimum luminance value and a maximum luminance value,
(ii) the image is encoded with digital code values D that represent a normalized color component value C based at least in part on a functional model of

C
=

(

Assignees

• Dolby Laboratories Licensing Corp

Inventors

• Miller Jon Scott
• Daly Scott
• Nezamabadi Mahdi
• Atkins Robin

Classifications

• G09G2370/04

  Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller · CPC title

• G09G2340/14

  Solving problems related to the presentation of information to be displayed · CPC title

• G09G2340/0435

  Change or adaptation of the frame rate of the video stream · CPC title

• H04N19/40

  using video transcoding, i.e. partial or full decoding of a coded input stream followed by re-encoding of the decoded output stream · CPC title

• G09G5/005

  Adapting incoming signals to the display format of the display terminal · CPC title