Optimizing Capture Of Focus Stacks

Patent metadata

Field	Value
Publication number	US-2016360091-A1
Application number	US-201514864565-A
Country	US
Kind code	A1
Filing date	Sep 24, 2015
Priority date	Jun 7, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

Generating a focus stack, including receiving initial focus data that identifies a plurality of target depths, positioning a lens at a first position to capture a first image at a first target depth of the plurality of target depths, determining, in response to capturing the first image and prior to capturing additional images, a sharpness metric for the first image, capturing, in response to determining that the sharpness metric for the first image is an unacceptable value, a second image at a second position based on the sharpness metric, wherein the second position is not included in the plurality of target depths, determining that a sharpness metric for the second image is an acceptable value, and generating a focus stack using the second image.

First claim

1 . A method of generating a focus stack, comprising:
receiving initial focus data that identifies a plurality of target depths; positioning a lens at a first position to capture a first image at a first target depth of the plurality of target depths;
determining, in response to capturing the first image and prior to capturing additional images, a sharpness metric for the first image;
capturing, in response to determining that the sharpness metric for the first image is an unacceptable value, a second image at a second position based on the sharpness metric, wherein the second position is not included in the plurality of target depths;
determining that a sharpness metric for the second image is an acceptable value; and
generating a focus stack using the second image.

2 . The method of claim 1 , further comprising:
positioning, in response to determining that the sharpness metric for the second image is an acceptable value, the lens at a second target depth of the plurality of target depths; and capturing a third image at the second target depth.

3 . The method of claim 1 , wherein the sharpness metric is calculated concurrently to moving the lens to a second target depth of the plurality of target depths.

4 . The method of claim 1 , further comprising, redirecting, in response to calculating the sharpness metric, the lens to the second position to capture the second image based on the sharpness metric, wherein the second position is associated with a new target depth that is not included in the initial focus data.

5 . The method of claim 1 , further comprising:
generating an all-focused image using the focus stack.

6 . The method of claim 1 , further comprising:
generating a depth map using the focus stack.

7 . The method of claim 1 , further comprising:
determining, in response to capturing the second image and prior to capturing additional images, a new sharpness metric based on the second image; capturing a third image at a third position based on the new sharpness metric; and modifying the focus stack using the third image.

8 . A system for generating a focus stack, comprising:
a lens assembly; a digital image sensor configured to receive light from the lens assembly; and a memory operatively coupled to the digital image sensor and comprising computer code configured to cause one or more processors to:
receive initial focus data that identifies a plurality of target depths;
position a lens at a first position to capture a first image at a first target depth of the plurality of target depths;
determine, in response to capturing the first image and prior to capturing additional images, a sharpness metric for the first image;
capture, in response to determining that the sharpness metric for the first image is an unacceptable value, a second image at a second position based on the sharpness metric, wherein the second position is not included in the plurality of target depths;
determining that a sharpness metric for the second image is an acceptable value; and
generating a focus stack using the second image.

9 . The system of claim 8 , the computer code further configured to cause the one or more processors to:
position, in response to determining that the sharpness metric for the second image is an acceptable value, the lens at a second target depth of the plurality of target depths; and capture a third image at the second target depth.

10 . The system of claim 8 , wherein the sharpness metric is calculated concurrently to moving the lens to a second target depth to capture a second intended image.

11 . The system of claim 8 , the computer code further configured to cause one or more processors to redirect, in response to calculating the sharpness metric, the lens to the second position to capture the second image based on the sharpness metric, wherein the second position is associated with a new target depth that is not included in the initial focus data.

12 . The system of claim 8 , wherein the computer code is further configured to cause the one or more processors to generate an all-focused image using the focus stack.

13 . The system of claim 8 , wherein the computer code is further configured to cause the one or more processors to generate a depth map using the focus stack.

14 . The system of claim 8 , the computer code further configured to cause one or more processors to:
determine, in response to capturing the second image and prior to capturing additional images, a new sharpness metric based on the second image; capture a third image at a third position based on the new sharpness metric; and modify the focus stack using the third image.

15 . A computer readable medium comprising computer code for generating a focus stack, the computer code executable by one or more processors to:
receive initial focus data that identifies a plurality of target depths; position a lens at a first position to capture a first image at a first target depth of the plurality of target depths; determine, in response to capturing the first image and prior to capturing additional images, a sharpness metric for the first image; capture, in response to determining that the sharpness metric for the first image is an unacceptable value, a second image at a second position based on the sharpness metric, wherein the second position is not included in the plurality of target depths; determining that a sharpness metric for the second image is an acceptable value; and generating a focus stack using the second image.

16 . The computer readable medium of claim 15 , the computer code further executable by one or more processors to:
position, in response to determining that the sharpness metric for the second image is an acceptable value, the lens at a second target depth of the plurality of target depths; and capture a third image at the second target depth.

17 . The computer readable medium of claim 15 , wherein the sharpness metric is calculated concurrently to moving the lens to a second target depth to capture a second intended image.

18 . The computer readable medium of claim 15 , the computer code further executable by one or more processors to redirect, in response to calculating the sharpness metric, the lens to the second position to capture the second image based on the sharpness metric, wherein the second position is associated with a new target depth that is not included in the plurality of target depths.

19 . The computer readable medium of claim 15 , the computer code further executable by one or more processors to generate an all-focused image using the focus stack.

20 . The computer readable medium of claim 15 , the computer code further executable by one or more processors to generate a depth map using the focus stack.

21 . The computer readable medium of claim 15 , the computer code further executable by the one or more processors to:
determine, in response to capturing the second image and prior to capturing additional images, a new sharpness metric based on the second image; capture a third image at a third position based on the new sharpness metric; and modify the focus stack using the third image.

Assignees

• Apple Inc

Inventors

• Lindskog Alexander
• Doepke Frank
• Brunner Ralf
• Bishop Thomas E

Classifications

• H04N23/959

  by adjusting depth of field during image capture, e.g. maximising or setting range based on scene characteristics · CPC title

• H04N23/743

  Bracketing, i.e. taking a series of images with varying exposure conditions · CPC title

• H04N25/60

  Noise processing, e.g. detecting, correcting, reducing or removing noise · CPC title

• H04N23/676 Primary

  Bracketing for image capture at varying focusing conditions · CPC title

• G02B27/0075 Primary

  with means for altering, e.g. increasing, the depth of field or depth of focus · CPC title