Method and apparatus for estimating point spread function

• US 8,830,363 B2
• Filed: 08/16/2013
• Issued: 09/09/2014
• Est. Priority Date: 11/20/2009
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jang, Soon-geun
• Primary Examiner(s): Pasiewicz, Daniel M
• Application Number:
  US13/968,916
• Publication Number:
  US 20130335593A1
• Time in Patent Office: 389 Days
• Field of Search: 348/222.1, 348/241, 348/208.99, 348/208.4, 348/208.6, 348/208.12, 382/201, 382/255, 382/260, 382/263
• US Class Current: 348/241
• CPC Class Codes: H04N 17/002 for television cameras
• CPC Class Codes: H04N 23/68 for stable pick-up of the scene, e.g. compensating for camera body vibrations
• CPC Class Codes: H04N 23/6811 based on the image signal
• CPC Class Codes: H04N 23/683 performed by a processor, e.g. controlling the readout of an image memory
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 23/743 Bracketing, i.e. taking a series of images with varying exposure conditions

Abstract

A method of estimating a point spread function (PSF) includes: estimating a global motion between a short-exposure image and a long-exposure image that are continuously captured using different exposure times, and compensating for the global motion; calculating a first resultant image by applying a band pass filter to the short-exposure image; calculating a second resultant image by applying the band pass filter to the long-exposure image; converting the first resultant image and the second resultant image into n-level images, where n is an odd natural number greater than or equal to 3, by deducing a first n-level resultant image and a second n-level resultant image from the first resultant image and the second resultant image, respectively; correlating the first n-level resultant image and the second n-level resultant image, and calculating a correlation map; and deducing the PSF from the correlation map.

Claims

1. A method of controlling a digital photographing apparatus, the method comprising:

continuously capturing a short-exposure image and a long-exposure image having different exposure times in response to one shutter-release button input; and

estimating a point spread function (PSF) from the short-exposure image and the long-exposure image,

wherein the short-exposure image has a shorter exposure time than the long-exposure image,

wherein a gain value of an imaging unit with respect to the short-exposure image is greater than a gain value of the imaging unit with respect to the long-exposure image, and

wherein a sum of the exposure times of the short-exposure image and the long-exposure image is determined depending on an exposure time set when the shutter-release button is input.

2. A digital photographing apparatus comprising:

an imaging unit;

an imaging unit controller that continuously captures a short-exposure image and a long-exposure image having different exposure times in response to one shutter-release button input; and

an apparatus for estimating a point spread function (PSF) that uses the short-exposure image and the long-exposure image to estimate the PSF of a captured image with respect to the shutter-release button input,

wherein the short-exposure image has a shorter exposure time than the long-exposure image,

wherein a gain value of the imaging unit with respect to the short-exposure image is greater than a gain value of the imaging unit with respect to the long-exposure image, and

wherein a sum of the exposure times of the short-exposure image and the long-exposure image is determined depending on an exposure time set when the shutter-release button is input.