Image formats and related methods and apparatuses

• US 9,420,196 B2
• Filed: 10/26/2015
• Issued: 08/16/2016
• Est. Priority Date: 09/26/2011
• Status: Active Grant

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: Atkins, Robin
• Primary Examiner(s): Moe, Aung S
• Assistant Examiner(s): Morehead, III, John H
• Application Number:
  US14/923,370
• Publication Number:
  US 20160050353A1
• Time in Patent Office: 295 Days
• US Class Current: 1/1
• CPC Class Codes: G06T 1/20 Processor architectures; Processor configuration, e.g. pipelining
• CPC Class Codes: G09G 2320/066 for control of contrast
• CPC Class Codes: G09G 2320/0673 for control of gamma adjustment, e.g. selecting another gamma curve
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3413 Details of control of colour illumination sources
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607
• CPC Class Codes: G09G 5/10 Intensity circuits
• CPC Class Codes: H04N 21/42202 environmental sensors, e.g. for detecting temperature, luminosity, pressure, earthquakes
• CPC Class Codes: H04N 21/4318 by altering the content in the rendering process, e.g. blanking, blurring or masking an image region image enhancement or restoration in general G06T5/00
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 5/262 Studio circuits, e.g. for mixing, switching-over, change of character of image, other special effects ; Cameras specially adapted for the electronic generation of special effects
• CPC Class Codes: H04N 5/57 Control of contrast or brightness

Abstract

Image data may be color graded, distributed and viewed on target displays. Mappings that preserve mid-range points and mid-range contrast may be applied to view the image data for color grading and to prepare the image data for display on a target display. The image data may be expanded to exploit the dynamic range of the target display without affecting mid-tone values.

Claims

1. An image capture device comprising:

a light-sensing array operable to detect light;

a mapping unit operatively coupled to the light-sensing array and configured to represent intensities of light sensed by elements of the light-sensing array as digital image values according to a response function; and

an exposure compensation circuitry operatively coupled to the mapping unit and configured to control the mapping unit such that a fixed point in the mid-range of the response function is made to correspond to a midpoint of the output image values,

the response function being based at least in part on a functional model of;

2. The image capture device according to claim 1 wherein the exposure compensation circuitry is configured to adjust a mid-range contrast of the response function based on an exposure.

3. The image capture device according to claim 2, wherein the exposure compensation circuitry adjusts the mid-range contrast via control of a value of the numeric parameter n.

4. The image capture device according to claim 2, wherein the exposure compensation circuitry sets the fixed-point via control of a value of the numeric parameter c₂.

5. The image capture device according to claim 1 wherein the response function corresponds to a response curve having a mid-tone slope, a dark end slope and a bright end slope and the mid-range slope is smaller than either of the dark end slope and the bright end slope.

6. The image capture device according to claim 1, wherein the exposure compensation circuitry controls the response function of the mapping unit according to a dynamic range and precision of the light-sensing array.

7. The image capture device according to claim 6, wherein the control of the response function is performed via adjustment of one or both of the numeric parameters c₁ and c₃.