ELECTRONIC DEVICE PERFORMING IMAGE CONVERSION, AND METHOD THEREOF

• US 20180232867A1
• Filed: 08/08/2016
• Published: 08/16/2018
• Est. Priority Date: 08/19/2015
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: PARK, Seung-ho, HAN, Seung-hoon, CHOI, Ji-won, WEY, Ho-cheon, MOON, Young-su
• Granted Patent: US 10,885,614 B2
• Time in Patent Office: Days
• CPC Class Codes: G06T 2200/21 involving computational photography
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/20208 High dynamic range [HDR] image processing
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/70 Denoising; Smoothing
• CPC Class Codes: G06T 5/92 based on global image properties
• CPC Class Codes: G06T 5/94 based on local image properties, e.g. for local contrast enhancement
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene

Abstract

An electronic device and an image conversion method of the electronic device, the electronic device comprising: a receiving unit for receiving a first image from a source device; a decoding unit for decoding brightness information of the first image; a converting unit for converting a dynamic range of the first image on the basis of the decoded brightness information, using a mapping function; and a display unit for displaying a second image having the converted dynamic range on a display, wherein the mapping function is a curve function including a plurality of points determined on the basis of the first image, a characteristic of a change in brightness of a display of the source device, and a characteristic of brightness of a scene of the first image. The present disclosure may generate, for example, a high dynamic range (HDR) image, which is improved from a standard dynamic range (SDR) image.

Claims

1. An electronic device, comprising:

a receiving unit for receiving a first image from a source device;

a decoding unit for decoding luminance information of the first image;

a converting unit for converting a dynamic range of the first image on the basis of the decoded luminance information, using a mapping function; and

a display unit for displaying a second image having the converted dynamic range on a display,

wherein the mapping function is a curve function including a plurality of points determined on the basis of a characteristic of a change in luminance of a display of the source device, and a characteristic of a change in luminance of a scene of the first image.

2. The electronic device as claimed in claim 1, wherein the mapping function is a piecewise linear function including a plurality of points, and

wherein a smoothing filter is applied to the piecewise linear function.

3. The electronic device as claimed in claim 1, wherein the plurality of points include a shadow point, which is a black level,

wherein the shadow point is converted from a black level of the first image to a black level of the display, and

wherein a low gradation black of the first image is maintained according to a ratio of a luminance of the first image to a luminance of the display.

4. The electronic device as claimed in claim 1, wherein the plurality of points include a peak point, which is a white level,

wherein the peak point is converted from a white level of the first image to a white level of the display, and

wherein a maximum luminance of a scene of the first image is mapped as a maximum luminance of the display.

5. The electronic device as claimed in claim 1, wherein the plurality of points include a middle point, which is an intermediate tone level,

wherein the middle point is converted from an intermediate tone level of the first image to an intermediate tone level of the display, and

wherein an average pixel level is adjusted based on a characteristic of a change in luminance of a display of the source device, and a characteristic of a change in luminance of a scene of the first image.

6. The electronic device as claimed in claim 1, wherein in response to a metadata including the plurality of points and parameter generating the mapping function being received from the source device, the plurality of points and the parameter are acquired from the metadata and a mapping function is generated by adjusting the plurality of acquired points and the acquired parameter.

7. The electronic device as claimed in claim 1, wherein the converting unit converts a dynamic range of the first image by applying a gain value obtained from the mapping function to primary colors of red (R), green (G), and blue (B) of the first image in the same manner.

8. The electronic device as claimed in claim 7, wherein the mapping function is

9. The electronic device as claimed in claim 8, wherein a function to preserve hue and saturation of the first image based on the mapping function is

10. An image conversion method, comprising:

receiving a first image from a source device;

decoding luminance information of the first image;

converting a dynamic range of the first image on the basis of the decoded luminance information, using a mapping function; and

displaying a second image having the converted dynamic range on a display,

wherein the mapping function is a curve function including a plurality of points determined on the basis of a characteristic of a change in luminance of a display of the source device, and a characteristic of a change in luminance of a scene of the first image.

11. The image conversion method as claimed in claim 10, wherein the mapping function is a piecewise linear function including a plurality of points, and

wherein a smoothing filter is applied to the piecewise linear function.

12. The image conversion method as claimed in claim 10, wherein the plurality of points include a shadow point, which is a black level of an image pixel,

wherein the shadow point is converted from a black level of the first image to a black level of the display, and maintains a low gradation black of the first image according to a ratio of a luminance of the first image to a luminance of the display.

13. The image conversion method as claimed in claim 10, wherein the plurality of points include a peak point, which is a white level,

wherein the peak point is converted from a white level of the first image to a white level of the display, and

wherein a maximum luminance of a scene of the first image is mapped as a maximum luminance of the display.

14. The image conversion method as claimed in claim 10, wherein the plurality of points include a middle point, which is an intermediate tone level,

wherein the middle point is converted from an intermediate tone level of the first image to an intermediate tone level of display, and adjusts an average pixel level on the basis of a characteristic of a change in luminance of a display of the source device, and a characteristic of a change in luminance of a scene of the first image.

15. The image conversion method as claimed in claim 10, further comprising:

in response to a metadata including the plurality of points and parameter generating the mapping function being received from the source device, acquiring the plurality of points and the parameter from the metadata and generating a mapping function by adjusting the plurality of acquired points and the acquired parameter.