JP2011131023A - Endoscope image processor, endoscope image displaying system, and endoscope image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an endoscope image processor, an endoscope image displaying system, and an endoscope image processing method by which distortion of a peripheral image is corrected to easily find out affected region while improving visibility of the center image of an endoscope image acquired by an endoscope with a wide viewing angle. <P>SOLUTION: The endoscope image processor 2 includes: an image separation part 4 to separate an endoscope image acquired by an endoscope capable of wide angle photographing into the center image and a hollow peripheral image around the center image; a peripheral image division part 5 to divide the peripheral image separated from the center image by the image separation part 4 in the circumferential direction to generate a plurality of sectorial peripheral image pieces; and an image correction part 6 to correct the distortion so that the length dimension in the circumferential direction of each peripheral image piece generated by the periphery image division part 5 becomes almost equal to the length dimension of the maximum width dimension of the center image. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an endoscope image processing apparatus, an endoscope image display system, and an endoscope image processing method.

  Conventionally, an endoscope having a wide-angle optical system whose viewing angle exceeds 180 ° is known as an endoscope (see, for example, Patent Document 1).

Special table 2007-536982 gazette

  However, in an endoscopic image acquired by an endoscope with such a wide viewing angle, although an endoscopic image over a wide range can be observed at a time as compared with an endoscope with a normal visual field, Since an image (peripheral image) in a region with a large angle of view (near the outer periphery) is compressed in the direction of the angle of view, the lesion site existing in this region is distorted, making it difficult to find the lesion site. There is a problem. Further, when the acquired endoscopic image is displayed on a single screen, the display ratio of the image (center image) in the region (center image) having a small angle of view (close to the center) by the peripheral image is reduced. Therefore, there is also an inconvenience that visual recognition becomes difficult.

  The present invention has been made in view of the above-described circumstances, and corrects distortion of a peripheral image while improving the visibility of a central image of an endoscopic image acquired by an endoscope having a wide viewing angle. It is an object of the present invention to provide an endoscopic image processing apparatus, an endoscopic image display system, and an endoscopic image processing method that can easily find a lesion site.

In order to achieve the above object, the present invention provides the following means.
The present invention provides an image separation unit that separates an endoscopic image acquired by an endoscope capable of wide-angle shooting into a central image and a hollow peripheral image around the endoscope image, and the image separation unit separates the central image from the central image. A peripheral image dividing unit that divides the peripheral image in the circumferential direction to generate a plurality of fan-shaped peripheral image pieces, and each peripheral image piece generated by the peripheral image dividing unit is substantially equal to the maximum width dimension of the central image. An endoscopic image processing apparatus is provided that includes an image correction unit that performs distortion correction to have a length dimension.
Note that the imaging described in the present invention indicates that an image formed by an optical system is acquired by an imaging element such as a CCD. The image acquired by the image sensor can be used for display on an image display system on the spot, or can be recorded on a recording medium.

  According to the present invention, after the peripheral image separated from the endoscopic image by the image separating unit is divided into a plurality of fan-shaped peripheral image pieces by the peripheral image dividing unit, the maximum width of the central image is obtained by the image correcting unit. The distortion is corrected so that the length is approximately the same as the size. This makes it possible to display the center image and the peripheral image piece side by side on a display screen that is slightly larger than the maximum width dimension of the center image. The center image is displayed on the entire display screen to improve visibility and distortion. The ease of finding a lesion site in the corrected peripheral image piece can be improved.

In the above invention, the endoscopic image may be circular, the central image may be an image of a circular area in the center of the endoscopic image, and the peripheral image may be annular.
In this way, since the degree of distortion of the annular peripheral image is uniform over the entire circumference, uniform distortion correction is applied to the fan-shaped peripheral image piece cut out from such a peripheral image. By applying this, distortion can be easily corrected.

In the above invention, the peripheral image dividing unit may generate the two fan-shaped peripheral image pieces by dividing the peripheral image.
In this way, without changing the compression rate in the angle of view, the peripheral image piece divided into two is simply compressed in the circumferential direction until it has a length substantially equal to the maximum width dimension of the central image. Distortion correction can be performed.

In the above invention, the image correction unit may correct the distortion so that the fan-shaped peripheral image piece has a substantially rectangular shape.
In this way, the subject included in the peripheral image piece can be acquired as an image with less distortion as if it were acquired as a central image.

Moreover, in the said invention, the said endoscopic image may have an angle of view exceeding 140 degrees.
In the above invention, the peripheral image may be an image of an area with an angle of view exceeding 140 °.
By doing so, it is possible to easily correct distortion in a region shot at a wide angle such that the angle of view exceeds 140 °, and it is possible to easily see a lesion site in this region and prevent oversight. .

Moreover, in the said invention, you may provide the image synthetic | combination part which produces | generates the synthesized image which arranged the said center image and the said peripheral image piece side by side.
In this way, it is possible to observe a composite image in a state where the center image and the peripheral image pieces whose distortion has been corrected are arranged.

In the above invention, the image composition unit may generate the composite image so that the aspect ratio is 9:16 to 10:16.
In this way, a composite image in a state where the center image arranged without waste and the peripheral image pieces corrected for distortion are arranged on a single screen is observed on a display device having an aspect ratio of 9:16 to 10:16. can do.

Further, the present invention provides an endoscopic image comprising any one of the endoscopic image processing devices described above and an image display device that displays the central image and the peripheral image pieces generated by the endoscopic image processing unit. Provide a display system.
According to the present invention, the central image and the peripheral image fragment generated by the endoscopic image processing device are displayed on the image display device, making it easy to see the lesion site existing in the wide-angle photographed region and preventing oversight. be able to.

In the above invention, the image display device may include a first display device that displays the central image and a second display device that displays the peripheral image piece.
In this way, the central image and the peripheral image piece can be displayed on separate display devices without being influenced by each other. Therefore, the central image can be displayed on the first display device with the maximum size, and the peripheral image piece whose distortion has been corrected can be displayed on the second display device with the maximum size.

In the above invention, the first or second display device may be a head-mounted display device.
The present invention also provides the endoscope image processing apparatus and an image display apparatus having a screen aspect ratio of 9:16 to 10:16 for displaying the composite image generated by the endoscope image processing unit. An endoscopic image display system is provided.
In the above invention, the image display device may be a head-mounted display device.

  The present invention also provides an image separation step for separating an endoscopic image acquired by an endoscope capable of wide-angle shooting into a central image and a hollow peripheral image around the endoscope image, and separation from the central image by the image separation step. A peripheral image dividing step for dividing the peripheral image in the circumferential direction to generate a plurality of fan-shaped peripheral image pieces, and a circumferential length dimension of each peripheral image piece generated by the peripheral image dividing step as the center There is provided an endoscopic image processing method including an image correction step of performing distortion correction so as to have a length dimension substantially equal to the maximum width dimension of an image.

In the above invention, the endoscopic image may be circular, the central image may be an image of a circular area in the center of the endoscopic image, and the peripheral image may be annular.
In the above invention, the peripheral image dividing step may generate two fan-shaped peripheral image pieces by dividing the peripheral image.

In the above invention, the image correcting step may correct the distortion so that the fan-shaped peripheral image piece has a substantially rectangular shape.
Furthermore, in the said invention, the said endoscopic image may have an angle of view exceeding 140 degrees.
In the above invention, the peripheral image may be an image of an area with an angle of view exceeding 140 °.

Further, the above invention may include an image composition step for generating a composite image in which the center image and the peripheral image pieces are arranged side by side.
In the above invention, the image composition unit may generate the composite image so that the aspect ratio is 9:16 to 10:16.

  According to the present invention, it is possible to improve the visibility of a central image of an endoscopic image acquired by an endoscope having a wide viewing angle, and to easily detect a lesion site by correcting distortion of a peripheral image. There is an effect that can be done.

1 is a block diagram showing an endoscopic image display system according to an embodiment of the present invention. It is a figure which each shows the center image and peripheral image which are isolate | separated from an endoscopic image by the endoscopic image display system of FIG. It is a figure which shows the case where a surrounding image is isolate | separated and two surrounding image pieces are produced | generated. It is a figure for demonstrating the image correction process which maps a semicircle fan-shaped periphery image piece to a rectangular area. It is a figure which shows the synthesized image produced | generated by the endoscopic image display system of FIG. It is a flowchart which shows the endoscopic image processing method which concerns on one Embodiment of this invention. It is a figure which shows the 1st modification of the synthesized image of FIG. It is a figure which shows the 2nd modification of the synthesized image of FIG. It is a figure which shows the 3rd modification of the synthesized image of FIG. It is a figure which shows the 4th modification of the synthesized image of FIG. It is a figure which shows the 5th modification of the synthesized image of FIG. It is a figure which shows an example which displays the center image produced | generated by the endoscope image display system of FIG. 1, and the periphery image piece after correction | amendment on a separate display screen. It is a figure which shows the other example of a display of FIG. It is a figure which shows the other example of a display of FIG.

An endoscope image processing apparatus, an endoscope image display system, and an endoscope image processing method according to an embodiment of the present invention will be described with reference to the drawings.
An endoscope image display system 1 according to the present embodiment includes an endoscope image processing device 2 that processes an endoscope image acquired by an endoscope capable of wide-angle shooting, and the endoscope image processing device 2. And an image display device 3 for displaying the generated image.

  An endoscope capable of wide-angle imaging has an imaging optical system having a viewing angle of, for example, 200 ° at the distal end of an elongated insertion portion that is inserted into a body cavity. That is, the case where the insertion portion is inserted into the body cavity will be described. The front front of the insertion portion toward the back side along the body cavity, the radially outer side (measurement) of the insertion portion facing the inner wall of the body cavity, and the insertion portion A wide range of endoscopic images extending diagonally backward toward the base end side can be acquired. When the body cavity is, for example, an intestinal tract having many folds on the inner wall, the back side of the fold can also be imaged.

  However, an endoscopic image obtained by such an endoscope capable of wide-angle imaging has little distortion in the central region, but is compressed in the direction of the angle of view as the angle of view increases. Distortion has occurred.

  As shown in FIG. 1, the endoscope image processing apparatus 2 according to the present embodiment separates an endoscopic image acquired by an endoscope into a central image and surrounding peripheral images. 4, a peripheral image dividing unit 5 that divides the peripheral image into two in the circumferential direction to generate two fan-shaped peripheral image pieces, and an image correction unit 6 that performs image correction on the two generated peripheral image pieces And an image synthesizing unit 7 for generating a synthesized image obtained by synthesizing the center image and the peripheral image pieces.

Endoscopic image G ₁ acquired by the endoscope is a circular image as shown in FIG. 2, measuring how the insertion portion and the central image G ₂ obtained by photographing the front side on the front of the insertion portion and obliquely rearward and the surrounding image G ₃ taken are included sequentially. The image separation unit 4 separates the central image G ₂ having an angle of view smaller than 140 ° and the peripheral image G ₃ having an angle of view of 140 ° or more from such an endoscopic image G _1. ing. Central image G ₂ is, becomes a circular image, the peripheral image G ₃ are a hollow annular image.

As shown in FIG. 3, the image dividing unit 5 divides the annular peripheral image G ₃ into two semicircular fan-shaped peripheral image pieces G ₃₁ and G ₃₂ .
Then, as shown in FIG. 4, the image correction unit 6 converts the sector area into a rectangular area having a height dimension equivalent to the diameter dimension of the central image G ₂ with respect to each of the peripheral image pieces G ₃₁ and G ₃₂ . Distortion correction that maps is performed.

As a result, the images of the respective parts constituting the peripheral image pieces G ₃₁ and G ₃₂ are compressed in the circumferential direction and expanded in the radial direction, and the arc-shaped area ABCDEF is changed into the rectangular area A′B′C′E ′. By mapping to F ′, distortion occurring in the image is corrected. The corrected peripheral image pieces G ₃₁ ′ and G ₃₂ ′ are images with little distortion as if the radially outer side of the insertion portion is arranged in front.

As shown in FIG. 5, the image composition unit 7 forms a composite image G in a form in which peripheral image pieces G ₃₁ ′ and G ₃₂ ′ corrected to a rectangle are arranged on both sides of the separated circular center image G _{2. 4} is generated. The image correcting unit 6 corrects the peripheral image pieces G ₃₁ ′ and G ₃₂ ′ so that the aspect ratio of the composite image G ₄ is, for example, 9:16.
The image display device 3 has a display screen with an aspect ratio of 9:16.

An endoscope image processing method using the endoscope image processing apparatus 2 and the endoscope image processing system 1 according to the present embodiment configured as described above will be described below.
Endoscopic image processing method according to the present embodiment, as shown in FIG. 6, an endoscopic image G ₁ obtained by the endoscopic central image G ₂ and the hollow of the peripheral image G ₃ surrounding separating the image separation step S1, a surrounding image dividing step S2 for generating a central image G ₂ has been surrounding image G ₃ 2 divided and in the circumferential direction of the two fan-shaped separate from the peripheral image pieces G _31, G ₃₂ an image correction step S3 to perform the distortion correction so that the generated two peripheral image fragment G _31, the diameter of the G ₃₂ each central image G ₂ and substantially equal length, each side of the central image G ₂ in, and an image synthesis step S4 of generating a composite image G ₄ which are arranged side by side around the image pieces G _31, G _32, respectively.

By separating the endoscopic image G ₁ in the central image G ₂ and the surrounding image G _3, as it is displayed on central image G ₂ less distortion, the large peripheral image G ₃ distortion, proper distortion correction To make it easier to see.
The center image G ₂ separating the peripheral image G ₃ are, therefore excluded a constraint that had displayed small in order to display the peripheral image G ₃ disposed on the periphery thereof of the image display device 3 The maximum display size can be displayed as long as the display screen is limited. Further, for the peripheral image G _3, since it is mapped to a rectangular area having substantially the same height and diameter dimensions of the central image G _2, central image G ₂ other than free space of the display screen of the aspect ratio 6:19 Can be displayed on a single screen.

In the peripheral image G ₃ in the endoscopic image G ₁ acquired in the annular region, the image is strongly compressed as the angle of view increases, and the lesion site existing in the peripheral image G ₃ is also greatly distorted. Although it was difficult to see, distortion was corrected by mapping to a rectangular area, making it easier to see. Therefore, there is an advantage that it is easy to find a lesion site on the display screen and it is possible to prevent the occurrence of oversight during observation.

In the present embodiment, the semicircular fan-shaped peripheral image pieces G ₃₁ and G _{32 obtained} by dividing the peripheral image G ₃ into two parts are mapped to rectangular regions, but the present invention is not limited to this. As shown in FIGS. 7 and 8, correction may be performed so as to map to an area other than the rectangle and reduce distortion of the image in the field angle direction.
Further, as shown in FIG. 9, the peripheral image pieces G ₃₁ and G ₃₂ may be displayed without waste as mapping to the entire empty area other than the central image G ₂ in the composite image G ₄ .

Further, as shown in FIG. 10, the correction may be be subjected so as to correct the distortion also central image G _2.
Further, as shown in FIG. 11, the composite image by reducing the proportion of the central image G ₂ in G _4, correspondingly, the peripheral image pieces G ₃₁ ', G _32' and to secure a large display region of Also good.

The center image G ₂ and the surrounding image piece G _{31 ',} G _32' and instead of being synthesized in the same composite image G4, as shown in FIG. 12, and to display a separate display screen Also good.
In this case, the arrangement direction of the peripheral image pieces G ₃₁ ′ and G ₃₂ ′ may be arranged vertically as shown in FIG. 12, or may be arranged left and right as shown in FIG.
Further, as shown in FIG. 14, the peripheral image pieces G ₃₁ ′ and G ₃₂ ′ may also be displayed on separate display screens.

Further, as the image display device 3, a head-mounted monitor may be adopted instead of a fixed normal monitor. In the example of displaying with two or more display screens, any one of the display screens may be a head-mounted type.
Further, in this embodiment, it was decided to divide the peripheral image G ₃ in two peripheral image fragment G _31, G _32, instead of this, it may be be divided into three or more.

Further, a circular image as the center image G _2, has been illustrated an annular image as peripheral images, the center image of the regular polygon, may be applicable to trapezoidal peripheral image of its surroundings.
Further, the aspect ratio of the composite image G ₄ was a 9:16, alternatively, it may be employed a composite image G ₄ of any other aspect ratio

Further, when the image is divided, the peripheral image pieces G ₃₁ and G ₃₂ may include a common portion in the boundary area. For example, instead of dividing into two 180 ° arcs as shown in FIG. 3, by making the arcs 180 ° or more, for example, 180-240 ° arcs, the overlap region of 0-30 ° Will have at both ends. In that case, the peripheral image pieces G ₃₁ ′ and G ₃₂ ′ may partially include a common part.

G ₁ endoscopic image G ₂ central image G ₃ near the image G _{31, G 32} surrounding the image piece G ₄ composite image S1 image separation step S2 surrounding image dividing step S3 image correction step S4 the image synthesizing step 1 endoscopic image display system 2 Endoscopic image processing device 3 Image display device 4 Image separation unit 5 Image division unit (peripheral image division unit)
6 Image correction unit 7 Image composition unit

Claims (21)

An image separation unit for separating an endoscopic image acquired by an endoscope capable of wide-angle imaging into a central image and a hollow peripheral image around the central image;
A peripheral image dividing unit that divides the peripheral image separated from the central image by the image separating unit in the circumferential direction to generate a plurality of fan-shaped peripheral image pieces;
An image correction unit that performs distortion correction so that the circumferential dimension of each peripheral image piece generated by the peripheral image dividing unit is approximately equal to the maximum width dimension of the central image. Endoscopic image processing device.   The endoscopic image processing apparatus according to claim 1, wherein the endoscopic image is circular, the central image is an image of a circular area in the center of the endoscopic image, and the peripheral image is annular. .   The endoscope image processing apparatus according to claim 1, wherein the peripheral image dividing unit generates two fan-shaped peripheral image pieces by dividing the peripheral image.   The endoscopic image processing device according to claim 1, wherein the image correction unit corrects the distortion of the fan-shaped peripheral image piece so as to have a substantially rectangular shape.   The endoscopic image processing apparatus according to claim 1, wherein the endoscopic image has an angle of view exceeding 140 °.   The endoscopic image processing device according to claim 5, wherein the peripheral image is an image of a region having an angle of view exceeding 140 °.   The endoscopic image processing apparatus according to any one of claims 1 to 6, further comprising an image composition unit that generates a composite image in which the center image and the peripheral image pieces are arranged side by side.   The endoscopic image processing apparatus according to claim 7, wherein the image composition unit generates the composite image so that an aspect ratio is 9:16 to 10:16. The endoscopic image processing device according to any one of claims 1 to 8,
An endoscopic image display system comprising: an image display device that displays the central image and the peripheral image pieces generated by the endoscopic image processing unit.   The endoscope image display system according to claim 9, wherein the image display device includes a first display device that displays the central image and a second display device that displays the peripheral image piece.   The endoscopic image display system according to claim 10, wherein the first or second display device is a head-mounted display device. An endoscopic image processing device according to claim 8,
An endoscope image display system comprising: an image display device having a screen aspect ratio of 9:16 to 10:16 for displaying the composite image generated by the endoscope image processing unit.   The endoscopic image display system according to claim 12, wherein the image display device is a head-mounted display device. An image separation step of separating an endoscopic image acquired by an endoscope capable of wide-angle imaging into a central image and a hollow peripheral image around it;
A peripheral image dividing step for generating a plurality of fan-shaped peripheral image pieces by dividing the peripheral image separated from the central image in the circumferential direction by the image separating step;
An endoscopic image processing method comprising: an image correction step of performing distortion correction so that each peripheral image piece generated by the peripheral image division step has a length dimension substantially equal to the maximum width dimension of the central image.   The endoscopic image processing method according to claim 14, wherein the endoscopic image is circular, the central image is an image of a circular area in the center of the endoscopic image, and the peripheral image is annular. .   The endoscopic image processing method according to claim 14, wherein the peripheral image dividing step generates two fan-shaped peripheral image pieces by dividing the peripheral image.   The endoscopic image processing method according to claim 14, wherein the image correction step corrects the distortion so that the fan-shaped peripheral image piece has a substantially rectangular shape.   The endoscopic image processing method according to claim 14, wherein the endoscopic image has an angle of view exceeding 140 °.   The endoscopic image processing method according to claim 18, wherein the peripheral image is an image of a region having an angle of view exceeding 140 °.   The endoscopic image processing method according to any one of claims 14 to 19, further comprising an image composition step of generating a composite image in which the center image and the peripheral image pieces are arranged side by side.   21. The endoscopic image processing method according to claim 20, wherein the image composition unit generates the composite image so that an aspect ratio is 9:16 to 10:16.

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