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"Image Processing Method, Image Processing Apparatus, Non-Transitory Computer-Readable Medium, and Image-Pickup Apparatus" in Patent Application...

August 29, 2014



"Image Processing Method, Image Processing Apparatus, Non-Transitory Computer-Readable Medium, and Image-Pickup Apparatus" in Patent Application Approval Process

By a News Reporter-Staff News Editor at Health & Medicine Week -- A patent application by the inventor EBE, Hiroki (Utsunomiya-shi, JP), filed on February 4, 2014, was made available online on August 14, 2014, according to news reporting originating from Washington, D.C., by NewsRx correspondents (see also Canon Kabushiki Kaisha).

This patent application is assigned to Canon Kabushiki Kaisha.

The following quote was obtained by the news editors from the background information supplied by the inventors: "The present invention relates to an image processing method, an image processing apparatus, a non-transitory computer-readable medium, and an image-pickup apparatus.

"An image captured through a wide-angle lens, an image captured by an image-pickup apparatus having a small image sensor size, and an image captured by an image-pickup apparatus having a small aperture diameter or a large F value has a deep depth of field with few blurs from a short-distant view to a long-distant view. In order to emphasize the main object and to relax the atmosphere, there have been proposed a variety of methods of blurring a captured image.

"For example, Japanese Patent Laid-Open No. ('JP') 2000-259823 proposes a method for obtaining distance information at a plurality of focus detection points for auto focusing (AF) and for blurring an input image. JP 11-41512 proposes an averaging method of pixel values in a user specified area in order to blur an input image. A. Rosenfeld (author), Makoto Nagao (translator), 'Digital Picture Processing,' Kindai kagaku sha Co., Ltd. (1978), proposes a variety of image processing methods of correcting a deteriorated input image. Other prior art contain Ren Ng et al., 'Light Field Photography with a Hand-Held Plenoptic Camera,' Stanford Tech Report CTSR, February of 2005.

"JP 2000-259823 and 11-41512 discuss methods of blurring the input image based upon the pixel value of the input image, but the pixel value of the input image is influenced by the optical characteristic of the image-pickup optical system regardless of the size of the image sensor and the focal length. An image shape formed on the image sensor is different from the object even at the in-focus position. At the in-focus position, the object in the periphery of the image is asymmetrically deformed due to the coma and the astigmatism. The image also deforms due to the diffraction. At a defocus position, the image deforms due to the vignetting in addition to the aberration and the diffraction. When a blur is added to an image that has deformed due blurring of the aberration, blurring of the diffraction, and blurring of vignetting, a blurring shape is unexpectedly different from one supposed by the object shape.

"For example, if a circularly symmetrical blur is added to a captured image (input image) of an object illustrated in FIG. 19A, the blurring shape is as expected from the object shape, as illustrated in FIG. 19B. However, when the captured image is influenced by the coma, the captured image of the object illustrated in FIG. 19A deforms as illustrated in FIG. 19C. If circularly symmetrical blurring is applied to this image (the image of FIG. 19C), the blurring shape is subject to the coma as illustrated in FIG. 19D.

"If the captured image is influenced by the astigmatism, the captured image illustrated in FIG. 19A deforms as extending in a specific direction. The image at the defocus position deforms due to blurring of the aberration and blurring of vignetting, for example, into an image lacking of part in the image illustrated in FIG. 19A. In other words, in order to obtain a good blurring shape as expected from the object shape, it is necessary to restrain image deformations caused by blurring of aberration, blurring of the diffraction, and blurring of vignetting.

"FIG. 20A is a graph illustrating the partially saturated brightness in an input image. In each of FIGS. 20A to 20C, an abscissa axis denotes a space coordinate and an ordinate axis denotes a brightness value. Herein, the saturation value is defined as a maximum brightness value that can be expressed in a digital image. If a blur is added to the brightness distribution of the image illustrated in FIG. 20A in which the brightness is partially saturated in the input image, a curve of the brightness distribution will be milder as illustrated in FIG. 20B than that of FIG. 20A. FIG. 20C illustrates an image obtained with a smaller F value (or under a brighter condition) than that of the image of FIG. 20A in order to blur an image with a shallow depth of field. The image illustrated in FIG. 20B is darker than that of FIG. 20C because the brightness is reduced. In other words, blurring cannot be well reproduced in an area of the brightness saturated part in an image captured with a small F value simply by blurring the input image."

In addition to the background information obtained for this patent application, NewsRx journalists also obtained the inventor's summary information for this patent application: "The present invention provides an image processing method, an image processing apparatus, a non-transitory computer-readable medium, and an image-pickup apparatus, which can generate a satisfactorily image.

"A non-transitory computer-readable medium for storing an image processing program configured to enable a computer to execute a shaping step of shaping an input image generated through capturing via an optical system by using a characteristic of the optical system and an image-pickup condition, a blurring step of blurring an image shaped by the shaping step, and a dividing step of dividing the input image into a plurality or layered images according to an object distance. The computer executes the shaping step based upon distance information of an object contained in each layered image.

"Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

"FIG. 1 is a block diagram of a principal part of an image-pickup apparatus according to a first embodiment of the present invention.

"FIGS. 2A and 2B are a schematic view and a sectional view of an image restoration filter stored in a memory illustrated in FIG. 1.

"FIGS. 3A to 3C are graphs for explaining the MTF of the image restoration according to a first embodiment.

"FIG. 4 is a flowchart for explaining an operation of an image processor illustrated in FIG. 1 according to the first embodiment.

"FIG. 5 is a view for explaining S12 illustrated in FIG. 4 according to the first embodiment.

"FIG. 6 is a schematic view for explaining an effect of the shaping step illustrated in FIG. 4 according to the first embodiment.

"FIGS. 7A to 7E are schematic views for explaining the effect of the shaping step illustrated in FIG. 4 according to the first embodiment.

"FIGS. 8A to 8C are graphs illustrating examples of a blurring function used in the blurring step illustrated in FIG. 4 according to the first embodiment.

"FIGS. 9A to 9D are schematic views of the images illustrated in FIGS. 7A-7E which has undergone S13 in FIG. 4 according to the first embodiment.

"FIG. 10 is a block diagram of a principal part of an image-pickup apparatus according to a second embodiment of the present invention.

"FIG. 11 is a flowchart for explaining an operation of an image processor illustrated in FIG. 10 according to the second embodiment.

"FIG. 12 is a drawing showing an example of a picked up scene including a brightness saturation part according to the second embodiment.

"FIGS. 13A and 13B are views for explaining a brightness estimation method used for S24 illustrated in FIG. 11 according to the second embodiment.

"FIG. 14 is a block diagram of a principal part of an image processing system according to a third embodiment of the present invention.

"FIG. 15 is a flowchart for explaining an operation of the image processing apparatus illustrated in FIG. 14 according to the third embodiment.

"FIG. 16 is a block diagram of a principal part of an image-pickup apparatus according to a fourth embodiment of the present invention.

"FIG. 17 is a flowchart for explaining an operation of the image processor illustrated in FIG. 10 according to the fourth embodiment.

"FIGS. 18A and 18B are views for explaining an effect of S44 illustrated in FIG. 17 according to the fourth embodiment.

"FIGS. 19A to 19D are views for explaining a relationship between an image deformation due to an optical characteristic of the imaging optical system and blurring.

"FIGS. 20A to 20C are graphs for explaining brightness saturation."

URL and more information on this patent application, see: EBE, Hiroki. Image Processing Method, Image Processing Apparatus, Non-Transitory Computer-Readable Medium, and Image-Pickup Apparatus. Filed February 4, 2014 and posted August 14, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=5069&p=102&f=G&l=50&d=PG01&S1=20140807.PD.&OS=PD/20140807&RS=PD/20140807

Keywords for this news article include: Canon Kabushiki Kaisha.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Health & Medicine Week


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