Method for processing image and electronic device supporting the same

Patent metadata

Field	Value
Publication number	US-10389951-B2
Application number	US-201715721435-A
Country	US
Kind code	B2
Filing date	Sep 29, 2017
Priority date	Sep 30, 2016
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

An electronic device includes a lens part that receives light from a subject, an image sensor that receives the light of the lens part from a group of pixels arranged two-dimensionally, and an processor that processes an image signal of the image sensor. The image sensor performs a read-out operation at a speed to prevent blurring of an image. The processor temporarily stores image data by the read-out operation in a memory, loads a plurality of images stored in the memory to generate an image, of which the number of bits is expanded compared with the image signal of the image sensor, and performs gamma processing on the image, of which the number of bits is expanded, to generate an image compressed to the same number of bits as the image signal of the image sensor.

First claim

What is claimed is:

1. An electronic device comprising:
a lens part configured to receive light from a subject;
an image sensor configured to receive the light of the lens part from a group of pixels arranged two-dimensionally; and
a processor configured to process an image signal of the image sensor,
wherein the image sensor performs a read-out operation with a read-out time which is shorter than a blurring limit time, wherein the blurring limit time is based on a focal length of the lens part,
wherein the processor is further configured to:
temporarily store image data by the read-out operation in a memory;
load a plurality of images stored in the memory to generate an expanded image, of which a number of bits and a dynamic range of each pixel are expanded compared with the image signal of the image sensor; and
perform gamma processing on the expanded image, to generate a compressed image compressed to a same number of bits as the image signal of the image sensor while the dynamic range of each pixel remains expanded.

2. The electronic device of claim 1 , wherein the image sensor is configured such that discontinuous breaks of a motion component of the subject in an interval between an exposure end of a first frame and an exposure start of a second frame with respect to a same row are adjusted to a size of a permissible circle of confusion (CoC) or larger on an upper surface of the image sensor.

3. The electronic device of claim 1 , wherein the plurality of images have a uniform exposure time.

4. The electronic device of claim 1 , wherein the plurality of images are formed of “N” frames, and
wherein the number of bits of the expanded image is ceil(log 2(N)).

5. The electronic device of claim 1 , wherein the processor is further configured to record a maximum value of the expanded image or an exposure distribution of the plurality of images; and
wherein the processor performs the gamma processing on the expanded image based on the recorded value.

6. The electronic device of claim 1 , wherein a sum of exposure times of the plurality of images is a same as or greater than an entire exposure time determined in advance by a setting of a user or by auto settings.

7. The electronic device of claim 1 , wherein the processor is further configured to perform a process of analyzing blurring or a motion with respect to an entire image or for each portion of the image and extracting a location variation of the subject.

8. The electronic device of claim 7 , wherein the processor is further configured to match the plurality of images by using the location variation.

9. The electronic device of claim 7 , wherein the processor is further configured to control an exposure time of the image sensor based on the location variation and a histogram of the entire image or of each portion of the image.

10. The electronic device of claim 7 , wherein the processor is further configured to control the image sensor to allow a first exposure time and a second exposure time to alternate, if the location variation is not more than a specified value and a histogram of the image is biased to a dark portion of the image.

11. The electronic device of claim 7 , wherein the processor is further configured to set an exposure time of the image sensor to be shorter than a reference exposure time, if the location variation is not more than a specified value and a histogram of the image is biased to a bright portion of the image.

12. The electronic device of claim 7 , wherein the processor is configured to:
set an exposure time of the image sensor to be longer than a reference exposure time; and
maintain an exposure time of each frame uniformly, if the location variation exceeds a specified value and a histogram of the image is biased to a dark portion of the image.

13. The electronic device of claim 7 , wherein the processor is configured to:
set an exposure time of the image sensor to be shorter than a reference exposure time; and
maintain an exposure time of each frame uniformly, if the location variation exceeds a specified value and a histogram of the image is biased to a bright portion of the image.

14. An image processing method performed in an electronic device, the method comprising:
receiving, at an image sensor, external light to generate an image signal by a photoelectric conversion effect;
performing, at the image sensor, a read-out operation with a read-out time which is shorter than a blurring limit time, wherein the blurring limit time is based on a focal length of a lens part;
storing image data by the read-out operation in a memory;
loading data of a plurality of images stored in the memory;
generating an expanded image, of which a number of bits and a dynamic range of each pixel are expanded compared with the image signal of the image sensor; and
performing gamma processing on the expanded image, to generate a compressed image compressed to a same number of bits as the image signal of the image sensor while the dynamic range of each pixel remains expanded.

15. The method of claim 14 , wherein the performing of the read-out operation includes performing a plurality of read-out operations during a specified reference time to generate data associated with the plurality of images.

16. The method of claim 14 , wherein the performing of the read-out operation includes reading out the plurality of images so as to have an uniform exposure time.

17. The method of claim 14 , further comprising:
recording a maximum value of the expanded image or an exposure distribution of the plurality of images; and
performing the gamma processing on the expanded image based on the recorded value or the exposure distribution.

18. The method of claim 14 , wherein the performing of the read-out operation includes performing the read-out operation such that a sum of exposure times of the plurality of images is the same or greater than an entire exposure time determined in advance by settings of a user or by auto settings.

19. The method of claim 14 , wherein the generating of the expanded image includes analyzing a motion with respect to an entire image or for each portion of the image to extract a location variation of a subject.

20. The method of claim 19 , wherein the generating of the expanded image includes matching the plurality of images by using the location variation, if a sum of exposure times of the plurality of images is greater than a reference exposure time.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Park Jae Hyoung
• Kim Byung Ho
• Moon Jae Joon
• Lee Jeong Won
• Kim Han Sung
• Choi Woo Seok
• Shimokawa Shuichi
• Usui Takafumi

Classifications

• H04N25/58

  involving two or more exposures · CPC title

• H04N23/6845 Primary

  by combination of a plurality of images sequentially taken · CPC title

• H04N23/73 Primary

  by influencing the exposure time · CPC title

• H04N23/741 Primary

  by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors · CPC title

• H04N23/683

  performed by a processor, e.g. controlling the readout of an image memory · CPC title