Method and apparatus for scoring an image

Patent metadata

Field	Value
Publication number	US-2016357784-A1
Application number	US-201615171095-A
Country	US
Kind code	A1
Filing date	Jun 2, 2016
Priority date	Jun 2, 2015
Publication date	Dec 8, 2016
Grant date	—

Abstract

Methods and apparatus for scoring an image based on visual criteria are described. A method includes computing a local blur map for the image, determining a bounding box in the image comprising a largest sharp region in the image based on the local blur map, scoring the image according to at least one of a ratio of bounding box size to image size, a ratio of the bounding box length to the bounding box height, a relative position of the bounding box in the image. Another method includes selecting an image among a plurality of images by scoring each image of the plurality of images according to the scoring method and selecting an image based on the score. The apparatus includes a memory and processor for performing the any of the selecting or the scoring method.

First claim

What is claimed is:

1 . A method for scoring an image comprising:
computing a local blur map for the image; determining a bounding box in the image comprising a largest sharp region in the image based on the local blur map; and scoring the image according to at least one of a ratio of bounding box size to image size, a ratio of the bounding box length to the bounding box height, a relative position of the bounding box in the image.

2 . The method of claim 1 , wherein the local blur map includes a blur metric for each pixel of the image.

3 . The method of claim 2 , wherein the blur metric is an average sum of singular values determined for a patch centered on said pixel of said image using a Singular Value Decomposition.

4 . The method of claim 2 , wherein the blur metric is an average sum of singular values determined for a patch centered on said pixel of a processed image using a Singular Value Decomposition, wherein the processed image is a difference image between said image and a blurred version of said image.

5 . The method of claim 1 , wherein the local blur map is a binary map and wherein the largest sharp region in the image is obtained by analyzing the connected components of the binary local blur map.

6 . The method of claim 1 , wherein scoring further comprises a global blur metric of the image.

7 . A method for selecting an image among a plurality of images comprising scoring each image of said plurality of images according to the method of claim 1 ; and
selecting an image based on the scores.

8 . An apparatus comprising a processor, coupled to a memory, configured to compute a local blur map for the image;
determine a bounding box in the image comprising a largest sharp region in the image based on the local blur map; and compute a score of the image according to at least one of a ratio of bounding box size to image size, a ratio of the bounding box length to the bounding box height, a relative position of the bounding box in the image.

9 . The apparatus according to claim 8 , wherein said apparatus belongs to a set comprising:
a mobile device; a communication device; a game device; a set top box; a TV set; a Blu-Ray disc player; a player; a tablet; a laptop; a display; and a camera.

10 . An apparatus for scoring an image comprising:
a module for computing a local blur map for the image; a module for determining a bounding box in the image comprising a largest sharp region in the image based on the local blur map; and a module for computing a score of the image according to at least one of a ratio of bounding box size to image size, a ratio of the bounding box length to the bounding box height, a relative position of the bounding box in the image.

11 . A non-transitory program storage device, readable by a computer, tangibly embodying a program of instructions executable by the computer to perform a method comprising:
computing a local blur map for the image; determining a bounding box in the image comprising a largest sharp region in the image based on the local blur map; and scoring the image according to at least one of a ratio of bounding box size to image size, a ratio of the bounding box length to the bounding box height, a relative position of the bounding box in the image.

Assignees

• Thomson Licensing

Inventors

• Ash Arden
• Hellier Pierre
• Lebrun Marc

Classifications

• G06F18/22

  Matching criteria, e.g. proximity measures · CPC title

• G06V10/255

  Detecting or recognising potential candidate objects based on visual cues, e.g. shapes · CPC title

• G06V10/993

  Evaluation of the quality of the acquired pattern · CPC title

• G06F17/30247 Primary

  Physics · mapped topic

• G06K2209/27

  Physics · mapped topic