US6201899B1
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Method and apparatus for extended depth of field imaging
Assignee: Sarnoff Corp
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Filing: 1999-01-15
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Granted: 2001-03-13
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Expires: 2019-01-15
Abstract
Abstract A method for constructing an extended depth of field image from a plurality of source images taken of an object at substantially identical fields of view but at differing focal distances, the method including receiving the plurality of source images, and filtering the plurality of source images to obtain relatively high frequency components in each of the filtered images. The energy levels of the high frequency components are estimated. The sub-regions in each filtered image having energy levels which are greater than energy levels of sub-regions in other filtered images are selected. The selected sub-regions of each filtered image are mapped to corresponding sub-regions in each source image. Finally, the corresponding sub-regions of the source images are merged to obtain the extended depth of field image.
Inventors
- 👤 James R. Bergen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:44
CPC Classifications
G; G06; G06V; G06V20/00; G06V20/60; G06V20/69; G06V20/693
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
148 words
A method for constructing an extended depth of field image from a plurality of source images taken of an object at substantially identical fields of view but at differing focal distances, the method comprising the steps of: a) receiving the plurality of source images, b) filtering the plurality of source images to obtain respective filtered images representing relatively high frequency components in each of the source images, c) estimating energy levels of the high frequency components in the filtered images, d) selecting sub-regions in each of the filtered images having energy levels which are greater than energy levels of sub-regions in other ones of the filtered images, e) mapping the selected sub-regions of each filtered image to corresponding sub-regions in each source image, and f) merging the corresponding sub-regions of the source images independently of any of the filtered images to obtain the extended depth of field image.
Claim 2
Independent Claim
148 words
A method for constructing an extended depth of field image from a plurality of source images taken of an object at substantially identical fields of view but at differing focal distances, the method comprising the steps of: a) receiving the plurality of source images, b) filtering the plurality of source images to obtain respective filtered images representing relatively high frequency components in each of the source images, c) estimating energy levels of the high frequency components in the filtered images, d) selecting sub-regions in each of the filtered images having energy levels which are greater than energy levels of sub-regions in other ones of the filtered images, e) mapping the selected sub-regions of each filtered image to corresponding sub-regions in each source image, and f) merging the corresponding sub-regions of the source images independently of any of the filtered images to obtain the extended depth of field image.
Claim 3
Dependent Claim
44 words
The method of claim 1 wherein the merging step includes forming a sub-region for the extended depth of field image by averaging one corresponding sub-region of one of the source images with at least one corresponding sub-region of another one of the source images.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein the filtering step includes constructing a Laplacian image for each source image.
Claim 5
Dependent Claim
32 words
The method of claim 3 wherein the Laplacian image includes an image from one of an L(0) level image, an L(1) level image, an L(2) level image and an L(3) level image.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein the filtering step includes constructing a plurality of images corresponding to a plurality of consecutive levels in a Laplacian pyramid.
Claim 7
Dependent Claim
35 words
The method of claim 1 wherein the filtering step includes filtering the source images according to a transfer characteristic of one of a finite impulse response high-pass filter and an infinite impulse response high-pass filter.
Claim 8
Dependent Claim
13 words
The method of claim 1 wherein each sub-region is an array of pixels.
Claim 9
Dependent Claim
12 words
The method of claim 1 wherein each sub-region is a single pixel.
Claim 10
Dependent Claim
138 words
A carrier conveying a plurality of instructions, the plurality of instructions including instructions which, when executed by a processor, cause the processor to perform the steps of: a) reading a plurality of source images, b) filtering, the plurality of source images to obtain respective filtered images representing relatively high frequency components in each of the source images, c) estimating energy levels of the high frequency components in the filtered images, d) selecting sub-regions in each of the filtered images having energy levels which are greater than energy levels of sub-regions in other ones of the filtered images, e) mapping the selected sub-regions of each filtered image to corresponding sub-regions in each source image, and f) merging the corresponding sub-regions of the source images independently of any of the filtered images to obtain the extended depth of field image.
Claim 11
Dependent Claim
138 words
A carrier conveying a plurality of instructions, the plurality of instructions including instructions which, when executed by a processor, cause the processor to perform the steps of: a) reading a plurality of source images, b) filtering, the plurality of source images to obtain respective filtered images representing relatively high frequency components in each of the source images, c) estimating energy levels of the high frequency components in the filtered images, d) selecting sub-regions in each of the filtered images having energy levels which are greater than energy levels of sub-regions in other ones of the filtered images, e) mapping the selected sub-regions of each filtered image to corresponding sub-regions in each source image, and f) merging the corresponding sub-regions of the source images independently of any of the filtered images to obtain the extended depth of field image.
Claim 12
Dependent Claim
51 words
The carrier of claim 9 wherein the instructions which implement the merging step cause the computer to form a sub-region for the extended depth of field image by averaging one corresponding sub-region of one of the source images with at least one corresponding sub-region of another one of the source images.
Claim 13
Dependent Claim
25 words
The carrier of claim 9 wherein the instructions which implement the filtering step cause the computer to construct a Laplacian image for each source image.
Claim 14
Dependent Claim
32 words
The carrier of claim 11 wherein the Laplacian image includes an image from one of an L(0) level image, an L(1) level image, an L(2) level image and an L(3) level image.
Claim 15
Dependent Claim
33 words
The carrier of claim 9 wherein the instructions which implement the filtering step cause the computer to construct a plurality of images corresponding to a plurality of consecutive levels in a Laplacian pyramid.
Claim 16
Dependent Claim
42 words
The carrier of claim 9 wherein the instructions which implement the filtering step cause the computer to filter the source images according to a transfer characteristic of one of a finite impulse response high-pass filter and an infinite impulse response high-pass filter.
Claim 17
Dependent Claim
146 words
Apparatus for constructing an extended depth of field image comprising means for obtaining a plurality of source images, each of the images representing an object at substantially identical fields of view but at differing focal distances, means for filtering the plurality of source images to obtain respective filtered images representing relatively high frequency components in each of the source images, means for estimating energy levels of the high frequency components in the filtered images, means for selecting sub-regions in each of the filtered images that have energy levels which are greater than energy levels of sub-regions in other ones of the filtered images, means for mapping the selected sub-regions of each filtered image to corresponding sub-regions in each source image, and means for merging the corresponding sub-regions of the source images independently of any of the filtered images to obtain the extended depth of field image.
Claim 18
Dependent Claim
146 words
Apparatus for constructing an extended depth of field image comprising means for obtaining a plurality of source images, each of the images representing an object at substantially identical fields of view but at differing focal distances, means for filtering the plurality of source images to obtain respective filtered images representing relatively high frequency components in each of the source images, means for estimating energy levels of the high frequency components in the filtered images, means for selecting sub-regions in each of the filtered images that have energy levels which are greater than energy levels of sub-regions in other ones of the filtered images, means for mapping the selected sub-regions of each filtered image to corresponding sub-regions in each source image, and means for merging the corresponding sub-regions of the source images independently of any of the filtered images to obtain the extended depth of field image.
Claim 19
Independent Claim
157 words
A method for constructing an extended depth of field image from a plurality of source images taken of an object from different fields of view, the method comprising the steps of: a) receiving the plurality of source images, b) aligning the plurality of source images by warping to obtain a plurality of warped images, c) filtering the plurality of warped images to obtain filtered images representing relatively high frequency components in each of the warped images, d) estimating energy levels of the high frequency components in the filtered images, e) selecting sub-regions in each of the filtered images having energy levels which are greater than energy levels of sub-regions in other ones of the filtered images, f) mapping the selected sub-regions of each filtered image to corresponding sub-regions in each warped image, and g) merging the corresponding sub-regions of the warped images independently of any of the filtered images to obtain the extended depth of field image.
Claim 20
Independent Claim
157 words
A method for constructing an extended depth of field image from a plurality of source images taken of an object from different fields of view, the method comprising the steps of: a) receiving the plurality of source images, b) aligning the plurality of source images by warping to obtain a plurality of warped images, c) filtering the plurality of warped images to obtain filtered images representing relatively high frequency components in each of the warped images, d) estimating energy levels of the high frequency components in the filtered images, e) selecting sub-regions in each of the filtered images having energy levels which are greater than energy levels of sub-regions in other ones of the filtered images, f) mapping the selected sub-regions of each filtered image to corresponding sub-regions in each warped image, and g) merging the corresponding sub-regions of the warped images independently of any of the filtered images to obtain the extended depth of field image.
Claim 21
Independent Claim
140 words
A method for constructing an extended depth of field image from a plurality of source images taken of an object at substantially identical fields of view but at differing focal distances, the method comprising the steps of: a) receiving the plurality of source images, b) filtering the plurality of source images to obtain respective filtered images representing relatively high frequency components in each of the source images, c) estimating energy levels of the high frequency components in the filtered images, d) selecting sub-regions in each of the filtered images having energy levels which are greater than a threshold value, e) mapping the selected sub-regions of each filtered image to corresponding sub-regions in each source image, and f) merging the corresponding sub-regions of the source images independently of any of the filtered images to obtain the extended depth of field image.
Claim 22
Independent Claim
140 words
A method for constructing an extended depth of field image from a plurality of source images taken of an object at substantially identical fields of view but at differing focal distances, the method comprising the steps of: a) receiving the plurality of source images, b) filtering the plurality of source images to obtain respective filtered images representing relatively high frequency components in each of the source images, c) estimating energy levels of the high frequency components in the filtered images, d) selecting sub-regions in each of the filtered images having energy levels which are greater than a threshold value, e) mapping the selected sub-regions of each filtered image to corresponding sub-regions in each source image, and f) merging the corresponding sub-regions of the source images independently of any of the filtered images to obtain the extended depth of field image.
Claim 23
Dependent Claim
59 words
The method of claim 17 wherein the merging step includes forming a sub-region for the extended depth of field image from one of the corresponding sub-regions of one of the source, the corresponding sub region having sample values greater in magnitude than corresponding sample values of another one of the corresponding sub-regions of another one of the source images.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-03-12 | 2004-09-11 | 2005-03-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-12 | 2008-09-11 | 2009-03-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-12 | 2012-09-11 | 2013-03-13 | $7700.00 | Window Closed / Lapsed |