IMAGING DEVICE PROVIDED WITH HIGH DYNAMIC RANGE RENDERING FUNCTION

• US 20180097984A1
• Filed: 10/02/2017
• Published: 04/05/2018
• Est. Priority Date: 10/03/2016
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Kobayashi, Kazuhiko, Murao, Toshikazu, Nishikawa, Masato
• Granted Patent: US 10,375,316 B2
• Time in Patent Office: Days
• CPC Class Codes: H04N 23/72 Combination of two or more compensation controls
• CPC Class Codes: H04N 23/741 by increasing the dynamic range of the image compared to the dynamic range of the electronic image sensors
• CPC Class Codes: H04N 23/743 Bracketing, i.e. taking a series of images with varying exposure conditions
• CPC Class Codes: H04N 25/58 involving two or more exposures
• CPC Class Codes: H04N 25/583 with different integration times
• CPC Class Codes: H04N 25/589 with different integration times, e.g. short and long exposures
• CPC Class Codes: H04N 25/745 Circuitry for generating timing or clock signals

Abstract

An imaging device performs imaging using an imaging element. The imaging device is provided with an imaging unit, a control unit and a synthesis unit. The imaging unit performs exposure with a predetermined exposure time, thereby performing image capture. The control unit successively performs an imaging process N-times. In each imaging process, a plurality of images are captured with different exposure times. The synthesis unit generates, using HDR rendering, a plurality of images acquired by the plurality of image captures. The control unit performs one of the plurality of image captures such that the exposure is completed at a corresponding synchronous timing, and performs a subsequent other image capture such that exposure is started at the synchronous timing.

Claims

1. An imaging device that performs imaging using an imaging element (12) comprising:

an imaging unit that performs exposure with a predetermined exposure time, thereby performing the imaging;

a control unit that successively performs an imaging process N-times thereby performing a plurality of imaging processes, where N is integer and 2 or more, a plurality of image captures with different exposure times being performed by the imaging unit in each of the imaging processes; and

a synthesis unit that generates, by using HDR rendering based on a plurality of images acquired by the plurality of image captures, a synthesis image having an expanded dynamic range and being generated for each of the N-times imaging processes,

wherein

each of the synthesis images generated for each of the N-times imaging processes has a predetermined image quality determined corresponding to each of the synthesis images;

a maximum exposure time of each capturing in each of the N-times imaging processes is determined based on the image quality of the synthesis image generated in corresponding imaging process;

each of the N-times imaging processes is performed in accordance with a corresponding synchronous timing, the N synchronous timings being at regular intervals;

the control unit successively performs, in each of the N imaging processes, the plurality of image captures before/after the corresponding synchronous timing;

the control unit performs one of the plurality of image captures such that the exposure is completed at a time when the synchronous timing comes, and performs a subsequent another capturing such that the exposure is started at a time when the synchronous timing comes; and

an exposure timing is determined in each of the imaging process based on the maximum exposure time such that exposure times in the N-times imaging processes are not overlapped.

2. The imaging device according to claim 1, wherein

the synthesis image is used for a driving assist in a vehicle;

different image objects are recognized based on a plurality of synthesis images generated by the N-times imaging processes in the driving assist; and

the image quality of each synthesis image generated by the N-times imaging processes is determined by each of the image objects recognized by the image captured in the imaging process.

3. The imaging device according to claim 2, wherein

the imaging device is mounted on the vehicle.

4. The imaging device according to claim 1, wherein

two types of imaging including a long-period exposure imaging and a short-period exposure imaging are performed as the plurality of image captures in each of the N-times image processes;

the exposure time of the long-period exposure imaging is longer than that of the short-period exposure imaging;

the exposure in one type of imaging in each of the N-times imaging processes is performed before the synchronous timing corresponding to a current imaging process in the N-times imaging processes, and the exposure in the other type of imaging in each of the N-time imaging processes is performed after the synchronous timing corresponding to the current imaging process in the N-times imaging processes, whereby the exposure times of respective imaging processes do not overlap with each other.

5. The imaging device according to claim 4, wherein

the control unit performs two different types of imaging in each of the N-times imaging processes.