Display Management Methods and Apparatus

• US 20130038790A1
• Filed: 02/18/2011
• Published: 02/14/2013
• Est. Priority Date: 02/24/2010
• Status: Active Grant

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: Seetzen, Helge, Messmer, Neil W., Damberg, Gerwin, Atkins, Robin
• Granted Patent: US 10,056,055 B2
• Time in Patent Office: Days
• US Class Current: 348/453
• CPC Class Codes: G09G 2320/0666 for control of colour parameters, e.g. colour temperature
• CPC Class Codes: G09G 2340/0485 Centering horizontally or vertically
• CPC Class Codes: G09G 2340/06 Colour space transformation
• CPC Class Codes: G09G 2340/10 Mixing of images, i.e. displayed pixel being the result of an operation, e.g. adding, on the corresponding input pixels
• CPC Class Codes: G09G 2360/144 the light being ambient light
• CPC Class Codes: G09G 2370/04 Exchange of auxiliary data, i.e. other than image data, between monitor and graphics controller
• 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: H04N 9/67 for matrixing camera processing pipelines for matrixing of colour signals H04N23/85

Abstract

Apparatus and methods for mapping video signal parameters such as tone and color may be applied at various points in a video generation and delivery pipeline. apparatus may be configured to control mappings based on a range of inputs which may include one or more of: ambient conditions, user inputs, control information, adaptation models. Apparatus and methods may be applied to display video or other images so as to preserve a creative intent embodied in video or other image data.

Claims

1-35. -35. (canceled)

36. A method for providing video signals for display on a target display, the method comprising:

receiving a first input video signal having a first format wherein a video parameter is represented within a first range;

receiving a second input video signal having a second format wherein the video parameter is represented within a second range different from the first range;

determining a target range of the target display;

generating a target value for the video parameter by extrapolating or interpolating from first and second values of the video parameter in the first and second input video signals based on the first range, the second range, and the target range; and

outputting the target value to the target display.

37. A method according to claim 36 wherein the video parameter comprises a tone or color value.

38. A method according to claim 37 comprising performing the extrapolating or interpolating for the tone or color value for pixels of a video frame.

39. A method according to claim 38 wherein for at least some of the pixels a value of the parameter is the same in the first and second input video signals.

40. A method according to claim 36 wherein the interpolation or extrapolation is performed in a perceptually linear color space.

41. A method according to claim 40 wherein the perceptually linear color space comprises an IPT, LogYxy or LogYu′

v′

color space.

42. A method according to claim 41 wherein the interpolation or extrapolation comprises tone mapping and the tone mapping comprises determining a weighted sum of logarithms of tone values from the first and second video signals.

43. A method according to claim 42 wherein, in the tone mapping, the weighted sum is determined using a weighting factor based on a difference between a maximum of the target range and a maximum of one of the first and second ranges.

44. A method according to claim 39 wherein the interpolation or extrapolation is performed on-the-fly for values of the video parameter specified for pixels in the first and second input video signals.

45. A method according to claim 39 wherein one of the first and second input video signals comprises a Rec. 709 video signal.

46. A method according to claim 39 wherein one of the first and second ranges covers the full range of parameter values perceptible by the human visual system.

47. A method according to claim 36 comprising, determining whether the capability of the target device matches a capability associated with one of the first input video signal and the second input video signal and, if so, passing the matching one of the first and second input video signals to the target device.

48. Apparatus for providing video signals for display, the apparatus comprising:

first and second inputs for receiving first and second input video signals;

a value extractor configured to extract corresponding first and second values from the first and second video signals;

an interpolation/extrapolation unit configured to interpolate or extrapolate between the first and second values to yield a target value and to write the target value into an output video signal;

an output connected to deliver the output video signal to a display.

49. Apparatus according to claim 48 wherein the interpolation/extrapolation unit is configured to perform interpolation or extrapolation based on:

a first range within which the first values lie, a second range within which the second values lie and a target range of the display.

50. Apparatus according to claim 48 comprising a color space transformation unit upstream from the interpolation/extrapolation unit, the color space transformation unit configured to transform pixel values from the first and second input video signals into a common color space.

51. Apparatus according to claim 48 comprising a switch configured to selectively pass one of the first and second input video signals to the output.

52. Apparatus according to claim 51 comprising a controller configured to operate the switch to pass one of the first and second input video signals to the output in response to determining that the one of the first and second input video signals matches a capability of the display.

53. An apparatus for pre-processing an input video signal received at a display, the apparatus comprising:

an input for receiving the input video signal;

a decoder for decoding high-quality video data;

a display management unit for producing a modified video signal from high-quality video data;

an auto detect block for detecting a format of the input video signal; and

a multiplexer connected to receive the modified video signal and the input video signal, and configured to pass the modified video signal for further processing when the format detected by the auto detect block is a high-quality video format, and otherwise configured to pass the input video signal for further processing.

54. A display management unit for producing a modified video signal for display on a target display, the display management unit comprising:

at least one video input connected to receive at least one input video signal;

an ambient input connected to receive information characterizing ambient conditions at the target display;

a metadata input connected to receive metadata characterizing one or more aspects of a creative intent for video content carried by the at least one input video signal;

a control input connected to receive control information; and

a display input connected to receive information regarding the target display.

55. Apparatus for mapping tone and/or color values in video signals, the apparatus comprising:

an input configured to receive an input video signal;

a metadata extraction unit configured to extract metadata from the input video signal;

a mapping unit configured to map tone and/or color values from the input video signal to corresponding mapped values according to a mapping function;

a setting unit configured to modify the mapping function in response to metadata extracted by the metadata extraction unit.

56. Apparatus according to claim 55 comprising one or more ambient light sensors configured to generate signals indicative of ambient lighting conditions at a display.

57. Apparatus according to claim 56 wherein the metadata includes data indicating one or more reference ambient conditions and setting unit is configured to modify the mapping function based at least in part on differences between the reference ambient conditions and ambient conditions as measured by the one or more ambient light sensors.

58. Apparatus according to claim 57 wherein the ambient light sensors are configured to detect color of ambient light at the display.

59. Apparatus according to claim 56 wherein the mapping unit comprises a lookup table and the setting unit is configured to write new values into the lookup table.

60. Apparatus according to claim 56 wherein the mapping unit comprises a plurality of lookup tables and the setting unit is configured to select one or more of the lookup tables to be active.

61. Apparatus for mapping tone and/or color values in video signals, the apparatus comprising:

an input configured to receive an input video signal;

a mapping unit configured to map tone and/or color values from the input video signal to corresponding mapped values according to one or more mapping functions to yield an output video signal;

a setting unit configured to change the one or more mapping functions in response to one or more input signals received at the apparatus.

62. Apparatus according to claim 61 wherein the input signals comprise input signals indicative of ambient light conditions at a display connected to display video content of the output video signal.

63. Apparatus according to claim 62 comprising one or more ambient light color sensors wherein the input signals comprise signals from the ambient light color sensors.

64. Video processing apparatus connectable upstream from a video display, the apparatus configured to receive an input video signal and to map color and/or tone values in the input video signal to mapped values within capabilities of the display to yield an output video signal and to pass the output video signal downstream to the display, the video processing apparatus comprising a communication interface configured to receive from the display data indicative of one or more capabilities of the display and a control system configured to adjust the mapping of color and/or tone to match the capabilities of the display.

65. Apparatus for mapping tone and/or color values in video signals, the apparatus comprising:

an input configured to receive an input video signal;

a mapping unit configured to map tone and/or color values from the input video signal to corresponding mapped values according to a mapping function to yield an output video signal comprising the mapped values;

a data analysis unit configured to determine a brightness measure corresponding to the output video signal;

a human visual system model configured to determine an estimated dark adaptation based on the brightness measure; and

a setting unit configured to change the mapping function in response to the estimated dark-adaptation.

66. Apparatus according to claim 65 wherein the mapping function maps color values.

67. A method for processing video data for display on a downstream display, the method comprising:

determining a capability of the downstream display to display images for which a specified data type has values in a target range;

automatically configuring a mapping to map values of the specified data-type that are outside of the target range into the target range;

receiving an input video signal for which the specified data type has values outside of the target range;

generating an output video signal by applying the mapping to the input video signal.

68. A method according to claim 67 wherein determining a capability of the downstream display comprises receiving from the downstream display data indicating the capability of the target display.

69. Apparatus comprising any new and inventive feature, combination of features or sub-combination of features as described herein or depicted in the accompanying drawings.

70. Methods involving any new and inventive steps, acts, combination of steps and/or acts or sub-combination of steps and/or acts as described herein.