Dual camera systems and methods for rapid 3a convergence and high dynamic range exposure metering

Patent metadata

Field	Value
Publication number	US-2016227100-A1
Application number	US-201514609264-A
Country	US
Kind code	A1
Filing date	Jan 29, 2015
Priority date	Jan 29, 2015
Publication date	Aug 4, 2016
Grant date	—

Abstract

Systems and methods for rapid automatic focus, automatic white balance, and automatic exposure control are disclosed. To reduce the time it takes to automatically focus, balance spectra, and set exposure period, a dual camera uses an auxiliary camera and auxiliary image processing module in addition to the main camera and main image processing module. The auxiliary camera may capture lower resolution and lower frame rate imagery that is processed by an auxiliary image processing module to determine focus, white balance, and exposure periods for the main camera and main image processing module. By initiating convergence for automatic focus (AF), automatic white balance (AWB) and automatic exposure control (AEC) before receiving a command to capture imagery, and processing lower resolution and lower frame rate imagery, AF, AWB, and AEC convergence delays are reduced for both standard and high dynamic range image capture.

First claim

What is claimed is:

1 . An apparatus comprising:
a main camera configured to receive main image capture information and capture an image using the image capture information; a main image processing module in communication with the main camera, the main image processing module configured to receive an image from the main camera, receive main image processing information, and process the image received from the main camera using the main image processing information; an auxiliary camera configured to capture an image; an auxiliary image processing module in communication with the auxiliary camera, the auxiliary image processing module configured to receive at least one image from the auxiliary camera and determine auxiliary control information based on the at least one image received from the auxiliary camera; and a camera controller in communication with the auxiliary image processing module, the camera controller configured to
receive the auxiliary control information from the auxiliary image processing module,
determine main image capture information and main image processing information from the auxiliary control information,
communicate the main image capture information to the main camera, and
communicate main image processing information to the main image processing module.

2 . The apparatus of claim 1 , wherein the main image capture information includes information for operating the main camera to perform autofocus operations and for controlling exposure.

3 . The apparatus of claim 2 , wherein the main camera is configured to use the additional main image capture information to perform autofocus operations and to control exposure.

4 . The apparatus of claim 1 , wherein the main image processing information comprises information for performing a white balance adjustment of an image received from the main camera.

5 . The apparatus of claim 1 , wherein the auxiliary control information comprises information for controlling the auxiliary camera and processing the auxiliary image.

6 . The apparatus of claim 4 , wherein auxiliary control information further comprises exposure information.

7 . The apparatus of claim 2 ,
wherein the main image processing module is further configured to determine main control information, and wherein the camera controller is configured to receive main control information from the main image processing module, determine additional main image capture information for autofocus and exposure control based at least in part on the auxiliary control information and the main control information, and communicate the additional main image capture information to the main camera.

8 . The apparatus of claim 7 , wherein the main camera is configured to use the additional main image capture information to perform autofocus operations and control exposure based on the additional main image capture information.

9 . The apparatus of claim 2 ,
wherein the auxiliary control information includes autofocus data, wherein the auxiliary camera comprises an auxiliary lens, and wherein the auxiliary image processing module and the auxiliary camera are collectively configured to determine the autofocus data by moving the auxiliary lens to a plurality of positions, capturing an image at each of the positions, and determining at which position an image includes the most high frequency information.

10 . The apparatus of claim 6 , wherein auxiliary control information comprises white balance information, and wherein the auxiliary image processing module is configured to determine the white balance information of an image captured by the auxiliary camera.

11 . The apparatus of claim 1 , wherein the camera controller is configured to switch to an auxiliary capture mode in response to powering on the apparatus or when the apparatus operates switches from a recording mode to a non-recording mode, the camera controller determining the main image capture information and the main image processing information while in the auxiliary image capture mode based on the at least one image received from the auxiliary camera.

12 . A method, comprising:
capturing at least one auxiliary image by an auxiliary camera; determining, by an auxiliary image processing module, auxiliary control information based on the at least one auxiliary image; determining, by a camera controller, main image capture information and main image processing information from the auxiliary control information; capturing at least one main image by a main camera using the main image capture information; receiving the at least one main image and main image processing information at a main image processing module; and processing, by the main image processing module, the at least one main image using the main image processing information.

13 . The method of claim 12 , wherein the auxiliary control information comprises autofocus information, exposure information and white balance information for controlling the auxiliary camera and processing the at least one auxiliary image.

14 . The method of claim 13 , wherein the main image capture information comprises autofocus information and exposure information for use by the main camera.

15 . The method of claim 13 , wherein the main image processing information comprises white balancing information, and wherein processing the at least one main image using the main image processing information comprises changing a color of the at least one image color based on the white balancing information.

16 . The method of claim 12 , further comprising:
switching to an auxiliary capture mode when the apparatus is powered on; and switching to an auxiliary capture mode when the apparatus switches from a recording mode to a non-recording mode, wherein the at least one auxiliary image is captured when the apparatus is in the auxiliary capture mode.

17 . The method of claim 12 , further comprising:
determining additional main control information based on the at least one main image; and communicating the additional main control information to the camera controller; and determining additional main image capture information by the camera controller, the additional main image capture information based at least in part on the auxiliary control information and the additional main control information.

18 . The method of claim 17 , further comprising:
communicating the additional main image capture information to the main camera; and using the additional main image capture information by the main camera to perform autofocus and control exposure while capturing at least one additional main image.

19 . The method of claim 17 , wherein the additional main control information is determined by the main image processing module.

20 . An apparatus comprising:
means for capturing at least one auxiliary image; means for determining auxiliary control information based on the at least one auxiliary image; means for determining main image capture information and main image processing information from the auxiliary control information; means for capturing at least one main image using the main image capture information; means for receiving the at least one main image and main image processing information at a means for processing the at least one main image; and means for processing the at least one main image using the main image processing information.

21 . The apparatus of claim 20 , wherein the auxiliary control information comprises autofocus informa

Assignees

• Qualcomm Inc

Inventors

• Liu Shizhong
• Wu Hung-Hsin
• Dayana Venkata Ravi Kiran
• Ravirala Narayana Karthik Sadanandam
• Mao Yonggui
• Shanmugavadivelu Karthikeyan

Classifications

• H04N23/68

  for stable pick-up of the scene, e.g. compensating for camera body vibrations · CPC title

• H04N23/67 Primary

  Focus control based on electronic image sensor signals · CPC title

• H04N23/90

  Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums · CPC title

• H04N23/65

  Control of camera operation in relation to power supply · CPC title

• H04N23/73

  by influencing the exposure time · CPC title