Dynamic range converter with pipelined architecture and methods for use therewith

Patent metadata

Field	Value
Publication number	US-9589313-B2
Application number	US-201514867312-A
Country	US
Kind code	B2
Filing date	Sep 28, 2015
Priority date	Jan 9, 2015
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

In various embodiments, a dynamic range converter includes a plurality of circuits configured in a processing pipeline for operation timed by a pixel clock. The plurality of circuits include a first color space converter to convert a source color space of a source video having a source dynamic range to nonlinear color space signals. A linearizer configured converts the nonlinear color space signals to linearized color space signals having a mastering dynamic range via a piecewise linear interpolation of a transfer function. A color volume transformer applies dynamic color transform metadata associated with the source video to generate master adjusted color space signals from the linearized color space signals. A delinearizer converts the master adjusted color space signals to nonlinearized color space signals via a piecewise linear interpolation of an inverse transfer function in accordance with a display dynamic range. A second color space converter converts the nonlinearized color space signals to display domain signals. Other embodiments are disclosed.

First claim

What is claimed is:

1. A dynamic range converter comprising:
a plurality of circuits configured in a processing pipeline for operation timed by a pixel clock, wherein the plurality of circuits include:
a first color space converter configured to convert a source color space of a source video having a source dynamic range to nonlinear color space signals;
a linearizer configured to convert the nonlinear color space signals to linearized color space signals having a mastering dynamic range via a piecewise linear interpolation of a transfer function;
a color volume transformer configured to apply dynamic color transform metadata associated with the source video to generate master adjusted color space signals from the linearized color space signals;
a delinearizer configured to convert the master adjusted color space signals to nonlinearized color space signals via a piecewise linear interpolation of an inverse transfer function in accordance with a display dynamic range; and
a second color space converter configured to convert the nonlinearized color space signals to display domain signals;
wherein the color volume transformer applies gamut shaping, luminance tone mapping, chrominance tone mapping and additional color space conversion and wherein the color volume transformer includes:
a third color space converter configured to that apply the gamut shaping to the linearized color space signals in accordance with the dynamic color transform metadata to generate gamut shaped components;
a first tone mapper configured to apply first tone mapping by scaling the gamut shaped components in accordance with the dynamic color transform metadata to generate first mapped components;
a fourth color space converter configured to color converts the first mapped components in accordance with the dynamic color transform metadata to generate color remapped components;
a second tone mapper configured to apply second tone mapping by scaling the color remapped components in accordance with the dynamic color transform metadata to generate second mapped components; and
a fifth color space converter configured to color converts the second mapped components in accordance with the dynamic color transform metadata to generate the master adjusted color space signals.

2. The dynamic range converter of claim 1 wherein each of the plurality of circuits output a pixel at a rate of one pixel per clock cycle of the pixel clock.

3. The dynamic range converter of claim 1 wherein the linearizer and nonlinearizer are responsive to first configuration data to selectively operate in a first mode of operation where the source dynamic range is a high dynamic range and the display dynamic range is a standard dynamic range are further responsive to second configuration data to selectively operate in a second mode of operation where the source dynamic range is a standard dynamic range and the display dynamic range is a high dynamic range.

4. The dynamic range converter of claim 1 wherein the plurality of circuits further include:
a compositer configured to layer the master adjusted color space signals with further data planes prior to delinearization by the delinearizer.

5. The dynamic range converter of claim 1 wherein the plurality of circuits further include:
a third color space converter configured to color converts the master adjusted color space signals prior to delinearization by the delinearizer.

6. The dynamic range converter of claim 1 wherein the first tone mapper operates in accordance with the dynamic color transform metadata to:
generate a weighted maximum of the gamut shaped components;
index the weighted maximum to a piecewise linear lookup table to obtain a scale factor for each of the gamut shaped components; and
multiply each scale factor by a corresponding one of the gamut shaped components to generate the first mapped components.

7. The dynamic range converter of claim 1 wherein the second tone mapper operates in accordance with the dynamic color transform metadata to:
generate a weighted maximum of the color remapped components;
index the weighted maximum to a piecewise linear lookup table to obtain a scale factor for each of the color remapped components; and
multiply each scale factor by a corresponding one of the color remapped components to generate the second mapped components.

8. The dynamic range converter of claim 1 wherein the plurality of circuits further include:
a dithering limiter configured to reduce a number of bits in display domain signals to generate video display data.

9. The dynamic range converter of claim 1 wherein the plurality of circuits further include:
a display encoder configured to generate encoded video display data, based on the display domain signals.

10. The dynamic range converter of claim 1 wherein the plurality of circuits convert the source video to the display domain signals with low-latency.

11. A method comprising:
controlling a plurality of circuits in a processing pipeline via a pixel clock, wherein the processing pipeline includes the following:
converting a source color space of a source video having a source dynamic range to nonlinear color space signals;
converting the nonlinear color space signals to linearized color space signals having a mastering dynamic range via a piecewise linear interpolation of a transfer function;
color volume transforming the linearized color space signals based on dynamic color transform metadata associated with the source video to generate master adjusted color space signals;
delinearizing the master adjusted color space signals to nonlinearized color space signals via a piecewise linear interpolation of an inverse transfer function in accordance with a display dynamic range; and
converting the nonlinearized color space signals to display domain signals;
wherein the color volume transforming includes:
applying gamut shaping to the linearized color space signals in accordance with the dynamic color transform metadata to generate gamut shaped components;
applying first tone mapping by scaling the gamut shaped components in accordance with the dynamic color transform metadata to generate first mapped components;
color converting the first mapped components in accordance with the dynamic color transform metadata to generate color remapped components;
applying second tone mapping by scaling the color remapped components in accordance with the dynamic color transform metadata to generate second mapped components; and
color converting the second mapped components in accordance with the dynamic color transform metadata to generate the master adjusted color space signals.

12. The method of claim 11 wherein each of the plurality of circuits output a pixel at a rate of one pixel per clock cycle of the pixel clock.

13. The method of claim 11 wherein the processing pipeline further includes:
layering the master adjusted color space signals with further data planes prior to delinearizing.

14. The method of claim 11 wherein the processing pipeline further includes:
color converting the master adjusted color space signals prior to prior to delinearizing.

Assignees

• Vixs Systems Inc

Inventors

• Wallace Bradley Arthur

Classifications

• H04N9/68

  for controlling the amplitude of colour signals, e.g. automatic chroma control circuits (H04N9/71, H04N9/73 take precedence; camera processing pipelines for controlling the colour saturation of colour signals H04N23/86) · CPC title

• H04N9/67

  for matrixing (camera processing pipelines for matrixing of colour signals H04N23/85) · CPC title

• G06T5/007

  Physics · mapped topic

• H04N5/20

  Circuitry for controlling amplitude response · CPC title

• G06T1/20 Primary

  Processor architectures; Processor configuration, e.g. pipelining · CPC title