Graphics blending for high dynamic range video

• US 9,230,338 B2
• Filed: 02/26/2015
• Issued: 01/05/2016
• Est. Priority Date: 03/05/2014
• Status: Active Grant

• Current Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Original Assignee: Dolby Laboratories Licensing Corporation (Dolby Laboratories Incorporated)
• Inventors: Kunkel, Timo, Atkins, Robin, Chen, Tao, Hulyalkar, Samir N., Pytlarz, Jaclyn Anne
• Primary Examiner(s): HAROLD, JEFFEREY F
• Assistant Examiner(s): Desir, Jean W
• Application Number:
  US14/631,950
• Publication Number:
  US 20150256860A1
• Time in Patent Office: 313 Days
• Field of Search: 348/598, 348/597, 348/589, 348/584, 348/600, 348/441, 345/619, 345/629, 345/630
• US Class Current: 1/1
• CPC Class Codes: G06T 11/60 Editing figures and text; Combining figures or text
• CPC Class Codes: G06T 5/00 Image enhancement or restoration
• CPC Class Codes: G09G 5/10 Intensity circuits
• CPC Class Codes: H04N 21/42653 for processing graphics
• CPC Class Codes: H04N 5/44504 Circuit details of the additional information generator, e.g. details of the character or graphics signal generator, overlay mixing circuits

Abstract

A method for merging graphics and high dynamic range video data is disclosed. In a video receiver, a display management process uses metadata to map input video data from a first dynamic range into the dynamic range of available graphics data. The remapped video signal is blended with the graphics data to generate a video composite signal. An inverse display management process uses the metadata to map the video composite signal to an output video signal with the first dynamic range. To alleviate perceptual tone-mapping jumps during video scene changes, a metadata transformer transforms the metadata to transformed so that on a television (TV) receiver metadata values transition smoothly between consecutive scenes. The TV receiver receives the output video signal and the transformed metadata to generate video data mapped to the dynamic range of the TV'"'"'s display.

Claims

1. In a video receiver, a method for blending graphics data, the method comprising:

receiving input graphics data at a first dynamic range;

receiving an input video signal at a second dynamic range, wherein the second dynamic range is different than the first dynamic range;

receiving metadata for the input video data;

applying a receiver display management process to the input video data and the received metadata to generate a first video signal at the first dynamic range;

blending the first video signal with the input graphics data to generate a composite video signal;

applying an inverse display management process to the composite video signal and the metadata to generate an output video signal at a third dynamic range;

transforming the metadata using a metadata transform function to generate transformed metadata; and

outputting the output video signal and the transformed metadata.

2. The method of claim 1, wherein the third dynamic range is the same as the second dynamic range.

3. The method of claim 1, wherein transforming the metadata comprises:

receiving a metadata parameter of a first value for a first scene and a second value for a second scene immediately following the first scene;

applying a transformation function to the metadata parameter so that it transitions from the first value to the second value within a transition time interval larger than zero.

4. The method of claim 3, wherein the transformation function comprises a low-pass filter function.

5. The method of claim 3, wherein the transformation function comprises an exponential function.

6. The method of claim 3, further comprising inserting one or more indications of a scene cut to the metadata during the transition period between the first value and the second value.

7. The method of claim 1, wherein the first dynamic range is a standard dynamic range and the second dynamic range is an enhanced dynamic range.

8. The method of claim 1, wherein the metadata comprises content-related metadata.

9. The method of claim 1, further comprising:

in a television set, receiving the output video signal and the transformed metadata; and

applying a TV display management process to the output video signal and the transformed metadata to generate a target display signal at a fourth dynamic range.

10. The method of claim 1, further comprising:

determining whether the first video signal and the input graphics data are in a perceptually quantized IPT color space, and if not, converting them from their original color space to the perceptually quantized IPT color space; and

performing the blending step in the perceptually quantized IPT color space.

11. The method of claim 10, wherein the IPT perceptual quantization is performed according to SMPTE ST 2084.

12. A non-transitory computer-readable storage medium having stored thereon computer-executable instruction for executing a method with a computer in accordance with claim 1.

13. An apparatus for blending graphics data, the apparatus comprising:

input means for receiving input graphics data at a first dynamic range;

input means for receiving an input video signal at a second dynamic range, wherein the second dynamic range is different than the first dynamic range;

input means for receiving metadata for the input video data;

a processor for applying a receiver display management process to the input video data and the received metadata to generate a first video signal at the first dynamic range;

a processor for blending the first video signal with the input graphics data to generate a composite video signal;

a processor for applying an inverse display management process to the composite video signal and the metadata to generate an output video signal at a third dynamic range;

a processor for transforming the metadata using a metadata transform function to generate transformed metadata; and

means for outputting the output video signal and the transformed metadata.

14. The apparatus of claim 13, further comprising:

determining whether the first video signal and the input graphics data are in a perceptually quantized IPT color space, and if not, converting them from their original color space to the perceptually quantized IPT color space; and

performing the blending step in the perceptually quantized IPT color space.