JP6793074B2 - Ultrasonic image processing equipment - Google Patents

Description

The present invention relates to an ultrasonic image processing apparatus.

An ultrasonic diagnostic apparatus is a typical example of an ultrasonic image processing apparatus that forms an ultrasonic image based on data obtained by transmitting and receiving ultrasonic waves. As the ultrasonic image, a two-dimensional image such as a B-mode image or a color Doppler image is well known. In addition, a device that forms an ultrasonic image (three-dimensional ultrasonic image) that three-dimensionally projects a tissue or a foetation in a living body based on volume data obtained three-dimensionally by transmitting and receiving ultrasonic waves is also known. (See, for example, Patent Document 1).

By the way, in the field of computer graphics, an image processing technique called ambient occlusion (environmental shielding) is known (see, for example, Patent Document 2). In ambient occlusion, the effect of ambient light on each pixel is evaluated according to how much each pixel in the image is shielded by the surrounding scene. Ambient occlusion can give the image a natural shading effect.

Japanese Unexamined Patent Publication No. 2012-5593 U.S. Pat. No. 8878849

For example, it is expected that a natural shading effect can be given to an ultrasonic image by using a shielding process (image processing) such as ambient occlusion. However, since the amount of calculation for shielding processing such as ambient occlusion is enormous, it is desirable to realize shielding processing suitable for ultrasonic images.

Therefore, an object of the present invention is to realize a shielding process suitable for an ultrasonic image. For example, it is desirable to realize a shielding process that can obtain a natural shading effect with a relatively small amount of calculation.

An ultrasonic image processing apparatus suitable as an aspect of the present invention sets the brightness information obtained for each line of sight from a plurality of lines of sight by calculation based on the volume data of ultrasonic waves as the pixel value of each pixel in the image plane. According to the calculation means for obtaining the pixel values of a plurality of pixels in the image plane, and each pixel in the image plane is a pixel of interest, and the shielding portion occupies the three-dimensional evaluation area at the depth corresponding to the pixel of interest. It is a means for calculating the degree of shielding of the pixel of interest, and by obtaining the difference value between the depth to the shielding portion and the depth to the boundary of the evaluation area for each line of sight passing through the evaluation area, a plurality of pixels passing through the evaluation area. Using a shielding degree calculation means for calculating the shielding degree of the pixel of interest based on a plurality of difference values obtained from the line of sight of, and a shielding degree calculated for each pixel with each of the plurality of pixels in the image plane as the pixel of interest. By correcting the pixel value of each pixel to obtain the pixel value after the shielding process, the shielding processing means for obtaining the pixel value after the shielding process of a plurality of pixels in the image surface and the shielding of the plurality of pixels in the image surface. It is characterized by having an image forming means for forming an ultrasonic image based on a pixel value after processing.

In the above device, by obtaining the difference value between the depth to the shielding portion and the depth to the boundary of the evaluation area for each line of sight passing through the evaluation area, a plurality of difference values obtained from a plurality of lines of sight passing through the evaluation area are obtained. The degree of shielding of the pixel of interest is calculated based on. According to the above device, the degree of shielding is calculated based on the difference value between the depth to the shielding portion and the depth to the boundary of the evaluation area. Therefore, for example, an operation such as spatial integration with a huge amount of calculation is used. Compared with the case of calculating the degree of shielding, the amount of calculation can be significantly reduced. Further, in the above device, the pixel value of each pixel is corrected by using the degree of shielding calculated for each pixel, and the pixel value after the shielding process is obtained. Thereby, for example, an ultrasonic image having a natural shadow can be formed.

For example, the shielding degree calculation means is in the X-axis direction in a three-dimensional coordinate system composed of an X-axis and a Y-axis corresponding to two directions in the image plane and a Z-axis corresponding to each line-of-sight direction. It is desirable that the evaluation region is a three-dimensional region that extends in the Y-axis direction and the Z-axis direction and surrounds the coordinates corresponding to the pixel of interest. The Z-axis direction corresponds to the direction of each line of sight, and a plurality of lines of sight are two-dimensionally arranged in a plane specified by, for example, the X-axis direction and the Y-axis direction. In this configuration, the evaluation area extends in the X-axis direction, the Y-axis direction, and the Z-axis direction, and an evaluation area suitable for the geometrical arrangement of a plurality of lines of sight is realized. A suitable specific example of the shape of the evaluation region is a rectangular parallelepiped or a cube, but the shape is not limited to these shapes. The evaluation region may have a shape such as a columnar prism (cylinder, elliptical prism, triangular prism, polygonal prism) having a height in the Z-axis direction.

Further, the shielding degree calculating means calculates the difference value as a calculation result in the Z-axis direction for each line of sight passing through the evaluation region, passes through the evaluation region, and is two-dimensional in the X-axis direction and the Y-axis direction. It is desirable to calculate the degree of shielding of the pixel of interest corresponding to the evaluation region based on the plurality of difference values obtained as the calculation result in the Z-axis direction from the plurality of lines of sight lined up in. According to this configuration, the degree of shielding of the pixel of interest can be calculated by obtaining a difference value for each line of sight from a plurality of lines of sight passing through the evaluation region. For example, the difference value may be obtained from all the lines of sight passing through the evaluation area, or the difference value may be obtained from a plurality of lines of sight discretely selected from all the lines of sight passing through the evaluation area. ..

Further, when the shielding processing means corrects the pixel value of each pixel by using the shielding degree, the shielding processing means adds a correction according to the enlargement ratio of the ultrasonic image to obtain the pixel value of each pixel after the shielding processing. It is desirable to obtain. According to this configuration, the degree of shielding processing can be adjusted according to the enlargement ratio of the ultrasonic image. For example, the larger the magnification, the stronger the degree of shielding, so that the visual impression of the ultrasonic image can be improved.

Further, the ultrasonic image processing device further has a storage means for storing depth data indicating the depth to the shielding portion for each line of sight of the plurality of lines of sight, and the shielding degree calculation means stores in the storage means. It is desirable to calculate the difference value between the depth to the shielded part and the depth to the boundary of the evaluation area for each line of sight passing through the evaluation area using the obtained depth data. According to this configuration, the difference value of the depth can be calculated by using the depth data stored in the storage means, so that the calculation load in the shielding degree calculation means is reduced.

Further, the functions corresponding to each part of the above-mentioned suitable ultrasonic image processing apparatus (including desirable specific examples) may be realized by a computer (including a tablet type terminal). For example, the computer is preferably described above by a program that causes the computer to realize the function as the calculation means, the function as the shielding degree calculation means, the function as the shielding processing means, and the function as the image forming means. It can function as an ultrasonic image processing device. The program may be stored in a computer-readable storage medium such as a disk or memory and provided to the computer via the storage medium, or may be provided to the computer via a telecommunication line such as the Internet. May be provided.

According to the present invention, a shielding process suitable for an ultrasonic image is realized. For example, according to a preferred embodiment of the present invention, by calculating the degree of shielding based on the difference value between the depth to the shielding portion and the depth to the boundary of the evaluation region, for example, spatial integration with a huge amount of calculation can be performed. Compared with the case of calculating the degree of shielding using calculation, the amount of calculation can be significantly reduced. Further, according to a preferred embodiment of the present invention, the pixel value of each pixel is corrected by using the degree of shielding calculated for each pixel to obtain the pixel value after the shielding process, so that, for example, a natural shadow can be obtained. An ultrasonic image can be formed.

It is an overall block diagram of the ultrasonic diagnostic apparatus which is a preferable specific example of this invention. It is a figure which shows the specific example of a rendering operation. It is a figure which shows the specific example of the three-dimensional evaluation area. It is a figure for demonstrating the magnification of an ultrasonic image.

FIG. 1 is an overall configuration diagram of an ultrasonic diagnostic apparatus which is a preferable specific example of the ultrasonic image processing apparatus according to the present invention. The probe 10 is an ultrasonic probe for a three-dimensional image, and transmits and receives ultrasonic waves in a three-dimensional space including a diagnostic object such as a foetation. For example, a two-dimensional array probe (matrix array probe) having a plurality of two-dimensionally arranged vibrating elements, a mechanical probe for mechanically moving a plurality of one-dimensionally arranged vibrating elements, and the like are suitable for the probe 10. This is a concrete example.

The transmission / reception unit 12 has functions as a transmission beam former and a reception beam former. That is, the transmission / reception unit 12 forms a transmission beam by outputting a transmission signal to each of the plurality of vibration elements included in the probe 10, and further, for a plurality of received signals obtained from the plurality of vibration elements. The received beam is formed by performing phasing addition processing or the like.

Further, the transmission / reception unit 12 three-dimensionally scans an ultrasonic beam (transmission beam and reception beam) in, for example, a three-dimensional space including a diagnosis target. As a result, the received ultrasonic wave data is collected from within the three-dimensional space including the diagnosis target.

The volume configuration unit 20 forms volume data corresponding to the three-dimensional space by performing reconstruction processing on the received data obtained from the three-dimensional space. The volume configuration unit 20 performs reconstruction processing such as coordinate conversion processing and interpolation processing on the received data obtained in the scanning coordinate system (for example, rθφ coordinate system), and corresponds to the orthogonal coordinate system (for example, xyz coordinate system). Form the volume data. Volume data is composed of a plurality of voxel data arranged three-dimensionally in, for example, a data space of a Cartesian coordinate system.

The rendering calculation unit 30 executes a rendering calculation (voxel calculation) based on a plurality of voxel data constituting the volume data.

FIG. 2 is a diagram showing a specific example of the rendering operation. In the rendering operation (rendering process), a virtual viewpoint is set outside the volume data 32 corresponding to the three-dimensional space, and a plurality of lines of sight (rays) 34 are set from the viewpoint side to the volume data 32. Set. Further, an arithmetic screen 36 that functions as an image plane is set. In FIG. 2, the screen 36 is shown on the opposite side of the viewpoint with the volume data 32 in between, but is arranged on the viewpoint side of the volume data 32 and is a reference for the depth described in detail later. It may be a position.

In the rendering calculation, for each line of sight of the plurality of lines of sight (rays) set for the volume data 32, a plurality of voxel data corresponding to the line of sight is processed. For example, from a plurality of voxel data constituting the volume data 32, a plurality of voxel data corresponding to each line of sight (arranged on each line of sight) can be obtained by interpolation processing or the like.

Returning to FIG. 1, the rendering calculation unit 30 sets the luminance information obtained for each line of sight from the plurality of lines of sight as the pixel value of each pixel by the rendering calculation of the brightness, so that the plurality of pixels in the screen (image surface) can be displayed. Get the pixel value. As a result, projected image data of luminance information with the screen as the projection surface is formed.

In the brightness rendering process, for each line of sight, voxel operations based on the rendering method using opacity (opacity) are sequentially performed on a plurality of voxel data (voxel brightness information) corresponding to the line of sight from the viewpoint side. Is executed. Then, as a result of the final voxel calculation for each line of sight, the luminance information corresponding to that line of sight is determined, and the luminance information obtained for each line of sight from the plurality of lines of sight is mapped to each pixel in the screen to display the screen. Projected image data of luminance information used as a projection surface is formed. The projected image data of the luminance information is output to the shielding processing unit 60.

Further, the rendering calculation unit 30 forms projected image data of depth information in which depth information obtained for each line of sight from a plurality of lines of sight is associated with each pixel. A preferred specific example of the projected image data of the depth information is the distance projected image data described in Patent Document 1.

The rendering calculation unit 30 executes, for example, a distance rendering process detailed in paragraph 0023 of Patent Document 1, calculates a distance D _out for each line of sight of a plurality of lines of sight, and calculates each line of sight. By associating the distance D _out with each pixel in the screen (image plane), the distance projection image data with the screen as the projection plane is obtained. The distance D _out is calculated by, for example, the equation 1.

In the equation 1, the distance _Di is the distance of the i-th (i is a natural number) voxel existing on each line of sight, and is calculated from, for example, the voxel pitch in the volume data. A _i is the opacity corresponding to the brightness value of the i-th voxel existing on each line of sight, and A _out-1, which is the integrated value of the opacity, is calculated by the equation 2.

The distance D _out calculated by the distance rendering process is the sum of the distance D _i of a plurality of voxels lined up on each line of sight using the opacity A _i , and is the same as the brightness rendering process on that line of sight. The integration ends under the condition (A _out = 1 or the last voxel on the line of sight).

The distance D _out is the integrated distance from the reference position on each line of sight (for example, the position of the screen set on the viewpoint side of the volume data), and corresponds to the depth seen from the reference position side on each line of sight. Therefore, for example, the distance D _out calculated for each line of sight of the plurality of lines of sight is stored in the depth data storage unit 40 as the depth data of each line of sight.

The shading processing unit 60 executes a shading process to give a shading effect to the ultrasonic image obtained by the rendering calculation, for example, the projected image data of the luminance information that three-dimensionally represents the diagnosis target such as a foetation. In order to obtain a natural shading effect, it is evaluated how much the point of interest in the ultrasonic image is influenced by the ambient light, which is the light from the surrounding environment. In the evaluation, for example, it is desirable to use the concept of ambient occlusion (environmental shielding).

Ambient occlusion (environmental shielding) examines how much attention is shielded by the surrounding environment. That is, the degree of shielding (degree of shielding) at the point of interest is evaluated. A specific example of a numerical value for evaluating the degree of shielding is the shielding rate, which is calculated by the shielding rate calculation unit 50.

The shielding rate calculation unit 50 uses each pixel in the screen (image surface) as a pixel of interest, and the shielding portion 50 occupies a three-dimensional evaluation area at a depth corresponding to the pixel of interest. Calculate the shielding rate.

FIG. 3 is a diagram showing a specific example of the three-dimensional evaluation region. FIG. 3 shows a rectangular (cube) evaluation area 52. In the XYZ coordinate system shown in FIG. 3, the X-axis corresponds to the horizontal direction of the screen 36, and the Y-axis corresponds to the vertical direction of the screen 36. Further, the Z axis corresponds to the direction of each line of sight 34 orthogonal to the screen 36.

The evaluation region 52 of the specific example shown in FIG. 3 is a sample having (2K + 1) widths (K is a natural number) in each axial direction of the X-axis, Y-axis, and Z-axis with the coordinate P corresponding to the depth of the pixel of interest as the center. It is a rectangular area (cube) corresponding to a point. For example, a total of (2K + 1) × (2K + 1) lines of sight 34 of (2K + 1) lines in the X-axis direction and (2K + 1) lines in the Y-axis direction pass through the evaluation area 52.

The shielding rate calculation unit 50 (FIG. 1) obtains a difference value between the depth to the shielding portion and the depth to the boundary of the evaluation area 52 for each line of sight 34 passing through the evaluation area 52, thereby performing the inside of the evaluation area 52. The shielding rate of the pixel of interest is calculated based on a plurality of difference values obtained from the plurality of lines of sight 34 passing through.

The shielding rate calculation unit 50 uses the depth data stored in the depth data storage unit 40 (FIG. 1) to reach the depth to the shielding portion and the boundary of the evaluation area 52 for each line of sight 34 passing through the evaluation area 52. Calculate the difference value of the depth.

The depth data storage unit 40 stores depth data indicating the depth to the shielded portion for each line of sight 34 of the plurality of line of sight 34. For example, the distance D _out calculated for each line of sight 34 by the distance rendering process in the rendering calculation unit 30 (FIG. 1) is a suitable specific example of the depth data, and the distance D _out calculated for each line of sight 34 is a suitable specific example. It is said to be the depth to the shielded part.

The shielding rate calculation unit 50 uses, for example, the equation 3 based on the depth data stored in the depth data storage unit 40, so that the shielding rate k _A (x, y) of the pixel of interest at the coordinates (x, y) ) Is calculated.

In Equation 3, z (x + i, y + j) is the depth data of the line of sight 34 passing through the coordinates (x + i, y + j). z (x, y) is the depth data of the line of sight 34 passing through the coordinates (x, y), and corresponds to the depth of the pixel of interest. Further, (z (x, y) -K) is a depth at a position shallower by a distance K than the depth z (x, y) of the pixel of interest, and is the z coordinate (on the Z axis) of the start surface of the evaluation region 52. Position).

Further, i of the sample number in the X-axis direction (the number for specifying the line of sight as a sample) is a value in the range of −K to + K, and j in the sample number in the Y-axis direction (the number for specifying the line of sight as a sample). Is also a value in the range of -K to + K.

In the calculation using the equation (3), it is desirable to target all the lines of sight 34 passing through the evaluation area 52. Since the calculation of the equation 3 is to evaluate the ratio (ratio) of the shielding portion in the evaluation area 52, it is sampled discretely without targeting all the lines of sight 34 passing through the evaluation area 52. The calculation may be simplified by targeting only a plurality of lines of sight 34.

In the calculation using the equation 3, since the difference value of the depth is used in the Z-axis direction, that is, the line-of-sight direction, the calculation result corresponding to the case where all the points (all voxels) lined up in the line-of-sight direction are sampled. Can be obtained.

The shading rate calculation unit 50 uses each of all the pixels in the screen 36 as a pixel of interest, and calculates the shading rate for each pixel by using, for example, Equation 3.

Returning to FIG. 1, the shielding processing unit 60 shades the ultrasonic image obtained by the rendering calculation of the brightness by the rendering calculation unit 30, for example, the projected image data of the brightness information that three-dimensionally expresses the diagnosis target such as a foetation. Performs shielding to give an effect. The shielding processing unit 60 uses the shielding rate calculated for each pixel in the screen by the shielding rate calculation unit 50 to correct the pixel value of the pixel to obtain the pixel value after the shielding process, thereby forming the inside of the screen. Obtain the pixel values after the shielding process for all the pixels of.

The shielding processing unit 60 calculates the pixel value (luminance value) after the shielding processing for each pixel in the screen by using, for example, the equation (4).

In Equation 4, _Iorg (x, y) is the pixel value (luminance value) of the pixel at the coordinates (x, y) in the screen before the shielding process, and k _A (x, y) is the coordinate (x, y). It is the shielding rate of the pixel at x, y), and _Inew (x, y) is the pixel value (luminance value) of the pixel at the coordinate (x, y) after the shielding process.

The shielding processing unit 60 targets all the pixels in the screen, that is, all the pixels constituting the projected image data of the luminance information, and calculates the pixel value after the shielding processing for each pixel by, for example, the equation four.

The image forming unit 70 forms an ultrasonic image based on the pixel values of a plurality of pixels in the screen after the shielding process. The image forming unit 70 forms an ultrasonic image based on, for example, the pixel values (luminance values) after the shielding processing for all the pixels constituting the projected image data of the luminance information obtained from the shielding processing unit 60. As a result, an ultrasonic image having a natural shadow effect while three-dimensionally expressing a diagnosis target such as a foetation is formed and displayed on the display unit 72.

In addition, when the shielding processing unit 60 corrects the pixel value of each pixel using the shielding ratio, the shielding processing unit 60 adds the correction according to the enlargement ratio of the ultrasonic image to obtain the pixel value after the shielding processing of the pixel. You may.

FIG. 4 is a diagram for explaining the enlargement ratio of the ultrasonic image. FIG. 4 shows specific examples of ultrasonic images before and after enlargement. The ultrasonic images before and after enlargement are images showing the same diagnostic object. For example, an ultrasonic image showing the entire body of the foetation is formed as an image before enlargement, and an ultrasonic image is formed as a large image of the face of the same foetation as an image after enlargement.

Enlargement ratio S is defined for example as _{"S =} D L / _{D S".} Here, D _S is the diagnostic object display size before enlargement (e.g. size on the display screen of the display unit 72), D _L is the display size after the enlargement of the same diagnostic object.

When the correction according to the enlargement ratio S of the ultrasonic image is applied, the shielding processing unit 60 calculates the pixel value (luminance value) after the shielding processing for each pixel in the screen by using, for example, Equation 5.

In the equation 5, _Iorg (x, y) is the pixel value (luminance value) of the pixel at the coordinates (x, y) in the screen before the shielding process, and k _A (x, y) is the coordinate (x, y). It is the shielding rate of the pixel at x, y), S is the enlargement rate, and _Inew (x, y) is the pixel value (luminance value) of the pixel at the coordinate (x, y) after the shielding process. ..

By making corrections according to the magnification of the ultrasonic image and increasing the darkness of the shielded position in proportion to the display size, for example, the display size becomes visible to the eyes of users such as doctors and examination engineers. The larger the value, the more shaded shadows will be, and it is possible to give the effect of shadows with a sense of presence.

The densities of the plurality of lines of sight 34 (FIG. 3) may be changed according to the enlargement ratio of the ultrasonic image. For example, the higher the magnification, the higher the density of the plurality of lines of sight 34 may be. For example, when forming an ultrasonic image in which the face of a foetation is greatly projected as an enlarged image, a plurality of lines of sight 34 are concentratedly arranged in a region corresponding to the face of the foetation. Further, although it is desirable that the size of the evaluation area 52 (FIG. 3) in the real space is fixed before and after the enlargement of the ultrasonic image, the size of the evaluation area 52 in the real space may be changed as necessary. It may be adjusted.

Returning to FIG. 1, the control unit 100 controls the inside of the ultrasonic diagnostic apparatus of FIG. 1 as a whole. The overall control by the control unit 100 also reflects instructions received from users such as doctors and laboratory technicians via the operation device 80.

Among the configurations shown in FIG. 1, each unit of the transmission / reception unit 12, the volume configuration unit 20, the rendering calculation unit 30, the shielding rate calculation unit 50, the shielding processing unit 60, and the image forming unit 70 includes, for example, an electric / electronic circuit, a processor, or the like. It can be realized by using hardware, and a device such as a memory may be used as needed in the realization. Further, at least a part of the functions corresponding to each of the above parts may be realized by a computer. That is, at least a part of the functions corresponding to each of the above parts may be realized by the cooperation of hardware such as a CPU, a processor, and a memory, and software (program) that defines the operation of the CPU and the processor.

The depth data storage unit 40 can be realized by a storage device such as a semiconductor memory or a hard disk drive. Preferable specific examples of the display unit 72 are a liquid crystal display, an organic EL (electroluminescence) display, and the like. The operation device 80 can be realized by, for example, at least one of a mouse, a keyboard, a trackball, a touch panel, and other switches. The control unit 100 can be realized, for example, by cooperating with hardware such as a CPU, a processor, and a memory, and software (program) that defines the operation of the CPU and the processor.

Further, among the configurations shown in FIG. 1, for example, the functions of the rendering calculation unit 30, the shielding rate calculation unit 50, the shielding processing unit 60, and the image forming unit 70 are realized by a computer, and the computer is made to function as an ultrasonic image processing device. You may.

Although preferred embodiments of the present invention have been described above, the above-described embodiments are merely examples in all respects, and do not limit the scope of the present invention. The present invention includes various modified forms without departing from its essence.

10 probe, 12 transmitter / receiver, 20 volume component, 30 rendering calculation unit, 40 depth data storage unit, 50 shielding rate calculation unit, 60 shielding processing unit, 70 image forming unit, 72 display unit, 80 operation device, 100 control unit ..

Claims (5)

A calculation means for obtaining the pixel values of a plurality of pixels in the image plane by converting the luminance information obtained for each line of sight from a plurality of lines of sight into the pixel values of each pixel in the image plane by the calculation based on the volume data of ultrasonic waves. ,
Each pixel in the image plane is regarded as a pixel of interest, and it is a means for calculating the degree of shielding of the pixel of interest according to the ratio of the shielding portion in the three-dimensional evaluation area at the depth corresponding to the pixel of interest. By obtaining the difference value between the depth to the shielding part and the depth to the boundary of the evaluation area for each line of sight passing through the inside, the pixel of interest is based on the plurality of difference values obtained from the plurality of lines of sight passing through the evaluation area. Shielding degree calculation means for calculating the shielding degree of
By using each of the plurality of pixels in the image plane as the pixel of interest and using the degree of shielding calculated for each pixel to correct the pixel value of each pixel to obtain the pixel value after the shielding process, a plurality of pixels in the image plane. A shielding processing means for obtaining the pixel value after the pixel shielding processing, and
An image forming means for forming an ultrasonic image based on the pixel values of a plurality of pixels in the image plane after the shielding process, and
Have a,
When the shielding processing means corrects the pixel value of each pixel by using the shielding degree, the shielding processing means adds a correction according to the enlargement ratio of the ultrasonic image to obtain the pixel value after the shielding processing of each pixel.
An ultrasonic image processing device characterized by this. In the ultrasonic image processing apparatus according to claim 1,
The shielding degree calculation means is a three-dimensional coordinate system composed of an X-axis and a Y-axis corresponding to two directions in the image plane and a Z-axis corresponding to each line-of-sight direction, and the X-axis direction and the Y-axis. The evaluation area is a three-dimensional area that extends in the direction and the Z-axis direction and surrounds the coordinates corresponding to the pixel of interest.
An ultrasonic image processing device characterized by this. In the ultrasonic image processing apparatus according to claim 2,
The shielding degree calculating means calculates the difference value as a calculation result in the Z-axis direction for each line of sight passing through the evaluation region, passes through the evaluation region, and is two-dimensionally arranged in the X-axis direction and the Y-axis direction. The degree of shielding of the pixel of interest corresponding to the evaluation region is calculated based on the plurality of difference values obtained as the calculation results in the Z-axis direction from the plurality of lines of sight.
An ultrasonic image processing device characterized by this. In the ultrasonic image processing apparatus according to claim 1 ,
Even if the enlargement ratio is changed, the size of the evaluation region in the real space is fixed.
An ultrasonic image processing device characterized by this. In the ultrasonic image processing apparatus according to any one of claims 1 to 4.
It further has a storage means for storing depth data indicating the depth to the shielded portion for each line of sight of a plurality of lines of sight.
The shielding degree calculating means calculates the difference value between the depth to the shielding portion and the depth to the boundary of the evaluation area for each line of sight passing through the evaluation area by using the depth data stored in the storage means.
An ultrasonic image processing device characterized by this.