Method and Apparatus for Adaptive Exposure Bracketing, Segmentation and Scene Organization

• US 20140267612A1
• Filed: 03/15/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Golden Edge Holding Corporation
• Original Assignee: Edge Technologies, Inc
• Inventors: El Dokor, Tarek, Cluster, Jordan, King, Joshua
• Granted Patent: US 10,721,448 B2
• Time in Patent Office: Days
• US Class Current: 348/46
• CPC Class Codes: G06V 10/60 relating to illumination properties, e.g. using a reflectance or lighting model
• CPC Class Codes: H04N 23/743 Bracketing, i.e. taking a series of images with varying exposure conditions
• CPC Class Codes: H04N 23/88 for colour balance, e.g. white-balance circuits or colour temperature control

Abstract

A method, system and computer program are provided that present a real-time approach to Chromaticity maximization to be used in image segmentation. The ambient illuminant in a scene may be first approximated. The input image may then be preprocessed to remove the impact of the illuminant, and approximate an ambient white light source instead. The resultant image is then choma-maximized. The result is an adaptive Chromaticity maximization algorithm capable of adapting to a wide dynamic range of illuminations. A segmentation algorithm is put in place as well that takes advantage of such an approach. This approach also has applications in HDR photography and real-time HDR video.

Claims

1. A method for imaging a scene comprising the steps of:

determining a camera response function based upon one or more images captured with a camera;

maximizing chroma in an image in accordance with at least the determined camera response function and one or more perceptual parameters resulting in color consistency; and

imaging the scene at an exposure resulting in the maximized chroma.

2. The method of claim 1, where in the step of maximizing chroma in an image further comprises the step of employing a set of rolling exposure images to track and compute a max chromaticity.

3. The method of claim 1, wherein the maximizing of chroma maintains color consistency between images.

4. The method of claim 1, further comprising the step of defining color consistency as a hue that is associated with max chromaticity.

5. A method for imaging a scene comprising the steps of:

determining a camera response function based upon one or more images captured with a camera;

segmenting one or more regions of interest within the one or more captured images;

maximizing chroma in each of the one or more regions of interest in accordance with the determined camera response function; and

imaging the scene an exposure resulting in the maximized chroma for one or more of the regions of interest.

6. The method of claim 5, further comprising the step of using an ambient illuminant approximator to minimize one or more effects of one or more light sources on the imaging of the scene.

7. The method of claim 6, further comprising the step of tracking color/hue consistency by modeling perceptual elements through the combination of illuminant approximation as well as Chromaticity maximization.

8. The method of claim 5, further comprising the step of segmenting the image based on combining simulated/estimated exposure settings and color/texture/motion features.

9. The method of claim 5, further comprising the step of creating a depth map based on segmentation, combining simulated exposure settings with features of color, texture and motion.

10. An exposure bracketing method, comprising the steps of:

determining a camera response function based upon one or more images captured with a camera;

maximizing chroma in an image in accordance with the determined camera response function;

defining a category for each imaged scene as one of under-exposed, over-exposed, stable-lux, well-exposed and night mode; and

imaging the scene in accordance with the defined category at an exposure resulting in the maximized chroma.

11. A method for imaging a scene, comprising the steps of:

determining a camera response function based upon one or more images captured with a camera;

estimating an illuminant;

modifying the colorspace of the camera response function in accordance with the estimated illuminant;

maximizing chroma in an image in accordance with the modified colorspace camera response function; and

imaging the scene at an exposure resulting in the maximized chroma.

12. A method for high dynamic range video recording, comprising the steps of:

determining a camera response function based upon one or more images captured with a camera;

estimating an illuminant;

modifying the colorspace of the camera response function in accordance with the estimated illuminant;

maximizing chroma in an image in accordance with the modified colorspace camera response function;

recording video images of a scene in accordance with an exposure, autofocus setting resulting in the maximized chroma.

13. A method for imaging a scene, comprising the steps of:

(a) incrementing an EV (Exposure Value) value;

(b) rendering a scene at the incremented EV value;

(c) computing a depth of any new components or pixels that are rendered;

(d) integrating these computed depths with an existing depth map;

(e) determining whether all desired EV values have been employed;

(f) returning to step (a) if it is determined that not all EV values have been employed; and

(g) rendering a final depth map if it is determined that all EV values have been employed.