JP3476244B2 - Projection image processing method and projection image processing device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a projection image processing method and a projection image processing apparatus in an image diagnostic apparatus, and more particularly to a projection image processing method and a projection image processing apparatus capable of effectively utilizing a dynamic range of signal processing and display.

[0002]

2. Description of the Related Art Projection (IP: Intensit) is the simplest three-dimensional image display in an image diagnostic apparatus.
y Projection) Processing is known. For example, using a series of IP images obtained by changing the observation direction at a fine angle, it becomes possible to stereoscopically observe the running of blood vessels and the relationship between the lesion site and blood vessels, etc., in the cine mode. Such three-dimensional observation is considered to be useful for determining the tumor size and malignancy / benignity. Further, it is expected that the diagnosis will be facilitated by generating a 3D image from a projection processing result of a large number of image data obtained by the helical scan to obtain one stereoscopic image.

Here, the IP processing is a projection obtained by extracting and projecting the maximum value (or minimum value, specific value) for each corresponding pixel for all original images to be processed. This is a process of obtaining an image (IP image). That is, in the case as shown in FIG. 9, all the processes of extracting the maximum value (or the minimum value, the specific value) in the same pixel are performed for the first to Nth original images obtained in the depth direction. It is performed for each pixel to obtain one projection image.

[0004]

When such IP processing is performed, MIP (Maximum Intensity Projection)
Since the maximum value is extracted in the processing to generate the projection image, the projection image finally generated tends to be biased in the direction in which the whole becomes bright.

On the contrary, MinIP (Minimum Intensity Pr
Since the projection image is generated by extracting the minimum value in the ojection) process, the projection image finally generated tends to be biased toward the dark side. In particular, there is a problem that it is difficult to confirm the contents of the projected image when the image is darkly biased.

That is, as a result of the brightness of the entire screen of the projected image generated by the IP processing being biased to one of the fixed ranges, the dynamic range of the image to be displayed is narrowed, and the display capability of the display section is reduced. Will not be fully utilized.

Further, when two types of images which are bright or dark are arranged side by side as described above, there is a problem that it is difficult to compare and examine due to the difference in the brightness of each image. The present invention has been made in view of the above points, and an object of the present invention is to provide a projection image processing method capable of executing an IP process capable of sufficiently utilizing the display capability of a display unit without uneven brightness of the projection image. It is to realize a projection image processing device.

[0008]

A first means for solving the above-mentioned problems is to execute a projection process for extracting a predetermined value preset for each pixel for a plurality of image data to generate a projection image. Then, the average brightness of the projection image is obtained, and the brightness of the projection image is adjusted so that the average brightness becomes a predetermined value.

A second means for solving the above-mentioned problems is to execute a projection process for extracting a predetermined value preset for each pixel for a plurality of image data, generate a projection image, and generate the projection image. The projection image processing method is characterized by obtaining a histogram of data values and appearance frequencies for each pixel, and changing the value of the brightness so that the appearance frequency of each brightness in the histogram is constant.

A third means for solving the above-mentioned problems executes a projection process for extracting a predetermined value preset for each pixel with respect to a plurality of image data, generates a projection image, and generates a projection image. The projection image processing method is characterized by performing different weighting for each pixel depending on a region.

A fourth means for solving the above-mentioned problem is to perform different weighting on each of the plurality of image data according to a predetermined image area, and to each of the plurality of weighted image data. The projection image processing method is characterized in that a projection image is obtained by performing a projection process for extracting a predetermined value set in advance for a pixel.

A fifth means for solving the above-mentioned problems is a projection processing means for executing a projection processing for extracting a predetermined value preset for each pixel for a plurality of image data, and generating a projection image. And a normalization processing unit that adjusts the brightness of the projection image such that the average brightness of the projection image generated by the projection processing unit is determined to be a predetermined value. It is a projection image processing device.

A sixth means for solving the above problems is a projection processing means for executing a projection processing for extracting a predetermined value for each pixel for a plurality of image data to generate a projection image, A normalization processing unit that obtains a histogram of the data value and the appearance frequency for each pixel of the projection image generated by the projection processing unit and changes the value of the luminance so that the appearance frequency of each luminance in the histogram becomes constant. The projection image processing device is characterized by being provided.

A seventh means for solving the above problem is a projection processing means for executing a projection processing for extracting a predetermined value for each pixel from a plurality of image data to generate a projection image, A projection image processing apparatus, comprising: a normalization processing unit that performs different weighting for each pixel depending on a region of the generated projection image.

An eighth means for solving the above problem is a projection processing means for executing a projection processing for extracting a predetermined value for each pixel for a plurality of image data, and generating a projection image, Normalization processing means for differently weighting each of the plurality of image data according to a predetermined image area, and a predetermined value preset for each pixel for the plurality of weighted image data And a projection processing unit that executes a projection process for extracting a projection image to generate a projection image.

[0016]

In the projection image processing method which is the first means for solving the problem, a predetermined value of the data for each pixel is extracted from a plurality of image data to create a projection image. Then, the average brightness of this projection image is obtained, and the brightness of the projection image is adjusted so that this average brightness becomes a predetermined value.

In the projection image processing method which is the second means for solving the problem, a predetermined value of the data for each pixel is extracted from a plurality of image data to create a projection image. Then, a histogram of the data value and the appearance frequency is obtained for each pixel of this projection image, and the value of the brightness is changed so that the appearance frequency of each brightness in this histogram is constant.

In the projection image processing method which is the third means for solving the problem, a predetermined value of data for each pixel is extracted from a plurality of image data to create a projection image. Then, different weighting is performed for each pixel depending on the area of the projected image.

In the projection image processing method which is the fourth means for solving the problem, different weighting is applied to each of a plurality of image data according to a predetermined image area, and the plurality of weighted plurality of image data are weighted. A predetermined value of data for each pixel is extracted from the image data to create a projection image.

In the projection image processing apparatus which is the fifth means for solving the problem, a predetermined value of data for each pixel is extracted from a plurality of image data to create a projection image. Then, the average brightness of this projection image is obtained, and the brightness of the projection image is adjusted so that this average brightness becomes a predetermined value.

In the projection image processing apparatus which is the sixth means for solving the problem, a predetermined value of data for each pixel is extracted from a plurality of image data to create a projection image. Then, a histogram of the data value and the appearance frequency is obtained for each pixel of this projection image, and the value of the brightness is changed so that the appearance frequency of each brightness in this histogram is constant.

In the projection image processing apparatus which is the seventh means for solving the problems, a predetermined value of the data for each pixel is extracted from a plurality of image data to create a projection image. Then, different weighting is performed for each pixel depending on the area of the projected image.

In the projection image processing apparatus which is the eighth means for solving the problem, different weighting is applied to each of the plurality of image data according to a predetermined image area, and the plurality of weighted plurality of image data are weighted. A predetermined value of data for each pixel is extracted from the image data to create a projection image.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings. First, an outline of the projection image processing apparatus will be described with reference to FIG. 1, and then a projection image processing method will be described with reference to FIG.

FIG. 1 is a block diagram showing a schematic configuration of the entire projection image processing apparatus of one embodiment of the present invention. In FIG. 1, a data storage unit 1 includes an MR (magnetic resonance imaging apparatus),
It is for temporarily storing image data obtained from a CT scanner, an ultrasonic diagnostic apparatus, etc., and is composed of a magnetic disk device, a magneto-optical disk device, or the like.

The IP processing unit 2 performs a projection (IP) process, which will be described later, on the image data read out from the data storage unit 1. The IP processing unit 2 is a computer device having a projection processing program installed therein or software such as an image processing processor. It is composed of hardware and firmware.

The normalization processing section 3 carries out various normalization processes for normalizing and correcting the brightness deviation and the like as described later on the projection image subjected to the projection process, and is a computer device equipped with a normalization processing program. Alternatively, it is composed of software such as an image processor, hardware, and firmware.

The display section 4 is composed of various display means and displays the normalized projection image. The operation of the projection image processing apparatus thus configured and the projection image processing method will be described with reference to the flowchart of FIG.

First, desired image data is read from the image data stored in the data storage unit 1 into the memory area in the IP processing unit 2 (step 1). The IP processing unit 2 executes a predetermined IP process on the read image data (step 2 in FIG. 2). Then, the reading of the image data and the IP processing are repeated until the predetermined number is reached (step 3 in FIG. 2) to generate a projected image. The normalization processing unit 3 executes the normalization processing on the projection image generated in this way (step 4 in FIG. 2), whereby the deviation in the brightness of the projection image immediately after the IP processing is corrected and the dynamic range is expanded. It Then, the projection image in which the bias of the brightness is corrected and the dynamic range is expanded in this way is displayed on the display unit 4. That is, by generating the normalized projection image, the unevenness of the brightness of the projection image is eliminated, and the dynamic range of the display unit 4 can be effectively used.

Here, the normalization processing (step 4 in FIG. 2) executed by the normalization processing means 3 means various normalizations for eliminating the unevenness of the brightness of the IP image whose brightness is biased by the result of the IP processing. However, for example, it is conceivable to adjust the brightness so that the average brightness value becomes the center value so that the dynamic range in the signal processing or the image display can be effectively utilized, and to change the allocation of brightness by referring to the brightness histogram. . Further, when a specific deviation in brightness occurs depending on the coordinates (position) of the IP image, conversion of brightness by coordinates or the like can be considered. Such various normalization processes will be described in detail below.

[Normalization Processing by Brightness Adjustment] First, the normalization processing by brightness adjustment will be described. Here, a case will be described where signal processing is performed with 64 levels of brightness from 0 to 63.

When the IP process (step 2 in FIG. 2) is the MIP process in which the projection process is performed with the maximum value, as shown in FIG. 3A, the side where the brightness average value of the projected image is close to the maximum value (63). Tends to be biased toward. Therefore, the brightness average value Yc is first obtained, and the image data is shifted so that the brightness average value Yc of the projected image becomes the central value (32) (FIG. 3B). Next, regarding the image data thus shifted,
The maximum value Yt of the image data is the maximum brightness of the signal processing (6
3), the luminance expansion is performed (see FIG. 3).
(C)). Such normalization processing can be performed by directly rewriting the data of each pixel of the projection image stored in the memory area in the normalization processing means 3 or by using a lookup table. .
Further, as shown in FIGS. 3 (a), 3 (b) and 3 (c), it is possible to perform this one time, instead of performing it stepwise like shift and expansion.

FIG. 4 shows a case where the IP processing (step 2 in FIG. 2) is the MinIP processing for performing the projection processing with the minimum value. In this case, as shown in FIG. 4A, the average brightness value of the projected image tends to be closer to the minimum value (0). Therefore, as shown in FIG. 4B, the image data is shifted so that the brightness average value Yc of the projected image becomes the central value (32). Next, with respect to the image data thus shifted, the brightness is expanded so that the minimum value Yb of the image data becomes the minimum brightness value (0) of the signal processing (FIG. 4C). This normalization processing is also performed by the normalization processing means 3
It is possible to directly rewrite the data of each pixel of the projected image stored in the internal memory area, or to rewrite it using a lookup table. Further, as shown in FIGS. 4 (a), 4 (b) and 4 (c), it is possible to perform this one time, instead of performing it stepwise like shift and expansion.

As described above, by shifting the average luminance Yc to the center value, it is possible to realize the projection image processing method and the projection image processing apparatus which can eliminate the bias of the luminance and effectively utilize the dynamic range of the signal processing system. In addition, a projection image processing method that can effectively use the dynamic range of a signal processing system by expanding the brightness so as to fill the blank part of the brightness (either the maximum brightness side, the minimum brightness side, or both) A projection image processing device can be realized.

Then, the average luminance is shifted to the center value, and the luminance is expanded so as to fill in the blank portion (the maximum luminance side in the MIP processing, the minimum luminance side in the MinIP processing) caused by the shift, whereby the luminance is biased. It is possible to realize a projection image processing method and a projection image processing device that effectively utilize the dynamic range of the signal processing system.

Note that the above description is based on MIP processing and MinIP.
In the case of the processing, the similar processing can be performed by the brightness shift and the brightness expansion in the same manner even when the brightness is biased due to the IP processing of the specific value.

[Normalization Processing by Histogram Flattening]
FIG. 5 is an explanatory diagram illustrating a case where normalization processing by histogram flattening (or histogram smoothing) is performed. As described above, the brightness (the brightness before the normalization processing) is biased by the IP processing (FIG. 5A). For this reason, the dynamic range of the signal processing system and the display unit is not effectively utilized. In this embodiment, the brightness obtained by the IP process is called the pre-normalization brightness, and the brightness to be converted and displayed by the normalization process described below (display brightness) is called the post-normalization brightness.

In order to eliminate the bias in the frequency of the pre-normalization luminance as shown in FIG. 5A and flatten the histogram, a rearrangement function as shown in FIG. 5B is prepared.
This rearrangement function has a large slope for a portion where the frequency of pre-normalization luminance is high and a small slope for a portion where the frequency is low. For example, it can be obtained by integrating the histogram. When such a rearrangement function is prepared and the pre-normalization luminance is assigned to the post-normalization luminance, the frequently-used pre-normalization luminance is assigned to a wide range of post-normalization luminance. The pre-normalization luminance having a small number is assigned to the post-normalization luminance in a narrow range. This normalization process is shown in FIG.
It suffices to prepare a conversion table (look-up table or the like) having the characteristics of (b) and convert the pre-normalization luminance.

By executing such normalization processing, the pre-normalization luminance having the frequency characteristic shown in FIG. 5A is rewritten by the rearrangement function shown in FIG. 5B, An image having a brightness with a constant frequency as shown in FIG. 5C is obtained.

In this way, by rearranging the data values and the luminances so that the frequencies of the respective luminances at the time of display are equal, there is no unevenness of the luminances and the dynamic range of the signal processing system can be effectively utilized. An image processing method and a projection image processing device can be realized. Although the above description is for the MIP process, the same process can be performed when the luminance is biased due to the MinIP process or the IP process of the specific value.

[Normalization Processing by Linear Transformation] FIG. 6 is an explanatory diagram for explaining the case where the normalization processing by linear transformation is performed. As described above, the IP processing causes uneven brightness (FIG. 6A). In addition, the brightness is often concentrated near the center without using the IP processing, and the dynamic range of the signal processing system and the display unit is not effectively utilized. In FIG. 6 (a), although the luminance has a dynamic range of Ya to Yb, a part of it Xa
Data are concentrated in ~ Xb.

Therefore, the luminance range is wider (Ya to Y).
Performs a linearly stretched transformation to b). Here, the linear conversion for converting the i-th data Xi into Yi so that the luminance range [Xa, Xb] of the original image becomes [Ya, Yb] is Yi = ((Yb-Ya) / (Xb-Xa) )) × (Xi −
Xa) + Ya. As a result of such linear conversion, FIG.
An image having a wide frequency as shown in (b) can be obtained.

In this way, by performing the linear conversion so that the luminance value range at the time of display is widened, the deviation of the luminance is reduced and the dynamic range of the signal processing system can be effectively utilized, and the projection image processing apparatus and the projection image processing apparatus. Can be realized.
Although the above description was for the case of MIP processing, Min
Similar processing can be performed even when there is a brightness deviation due to the IP processing or the IP processing of a specific value. Further, it is also possible to execute the linear conversion by ignoring the infrequent data, by setting the luminance having a predetermined frequency as the above Xa and Xb.

[Normalization Processing by Weighting (1)] Depending on the type of image, it may be possible to predict in advance that a low brightness portion (shading) will occur depending on the coordinate position. For example, in an ultrasonic diagnostic apparatus or the like, a pixel (a corner portion of an image) located at a position distant from a detection unit (probe) may have a phenomenon in which brightness is reduced due to large attenuation of ultrasonic waves. When the characteristics of the image such as a low-luminance area and a high-luminance area can be assumed in advance, the compensation gain (Gain
(x, y)), and the data of each pixel (Data (x, y))
It is possible to perform the normalization processing by multiplying by the compensation gain (Gain (x, y)). By executing the normalization processing by the amplification weighted with the compensation gain, it becomes possible to correct the shading determined depending on the coordinate position of the image.

Regarding the normalization processing by such weighting, in addition to the processing procedure shown in FIG. 2, it is possible to execute the normalization processing before the IP processing as shown in FIG.

[Normalization processing by weighting (2)] As the normalization processing by weighting, weighting is performed by obtaining a gain for each pixel such that the average luminance value including the surrounding pixels becomes a predetermined value. It is also possible to carry out a normalization process by amplification. For example, as shown in FIG. 8, a luminance average value before normalization processing of 5 × 5 pixels around this pixel (x, y) (this range is called a window) is calculated to obtain the pixel of interest (x, y). The weighting gain G (x, y) for setting the brightness D (x, y) of G is obtained.

Here, the brightness before normalization processing at pixel (i, j) is D (i, j), the window width in the x direction is ω x, the window width in the y direction is ω y, and the target brightness is A. , The gain of pixel (x, y) is G (x, y), and the luminance after the normalization process at pixel (i, j) is Dne
If w (i, j),

[0048]

[Equation 1]

It becomes In this way, the gain G (x, y) for each pixel x, y is obtained, and the multiplication of this gain by the luminance of each pixel is performed for all pixels. As a result, the brightness of each pixel is distributed evenly around the target brightness A, and the brightness is prevented from being biased to a specific value. Therefore, it is possible to realize a projection image processing method and a projection image processing apparatus which can eliminate the bias of the luminance and effectively utilize the dynamic range of the signal processing system.

As described above in detail, the projection process for extracting a predetermined value set for each pixel from a plurality of image data is executed to generate a projection image, and the average brightness of the projection image is obtained. According to the projection image processing method that adjusts the brightness of the projection image so that the average brightness becomes a predetermined value, the bias of the brightness is eliminated and the dynamic range of the signal processing system can be effectively utilized.

Further, a projection process for extracting a predetermined value preset for each pixel from a plurality of image data is executed to generate a projection image, and the brightness value of the average brightness of the projection image is set to the lowest brightness side and the highest brightness side. According to the projection image processing method extending to the luminance side, the dynamic range of the signal processing system can be effectively used.

Further, projection processing for extracting a predetermined value for each pixel from a plurality of image data is executed to generate a projection image, the average brightness of this projection image is obtained, and this average brightness is calculated in advance. According to the projection image processing method of adjusting the brightness of the projected image so that the value becomes a predetermined value, and further expanding the brightness value of the average brightness of the projected image to the minimum brightness side and the maximum brightness side, there is no deviation in brightness. The dynamic range of the processing system can be effectively utilized.

A projection image is generated by performing a projection process for extracting a predetermined value for each pixel from a plurality of image data, and a histogram of data values and appearance frequencies is generated for each pixel of this projection image. According to the projection image processing method in which the luminance value is changed so that the appearance frequency of each luminance in this histogram is constant, the deviation of the appearance frequency of the luminance is eliminated and the dynamic range of the signal processing system can be effectively used. Like

Further, a projection process for extracting a predetermined value set for each pixel from a plurality of image data is executed to generate a projection image, and the projection image is weighted differently depending on the area of the projection image. According to the image processing method, it is possible to effectively utilize the dynamic range of the signal processing system because there is no unevenness in brightness depending on the area.

Further, different weighting is applied to each of the plurality of image data according to a predetermined image area, and a predetermined value set in advance for each pixel is applied to the plurality of weighted image data. According to the projection image processing method for executing the projection process for taking out and obtaining the projection image, since the projection image is generated in a state where there is no bias in the brightness depending on the area, the dynamic range of the signal processing system can be effectively utilized. Become.

Further, projection processing for extracting a predetermined value set for each pixel from a plurality of image data is executed to generate a projection image, and the brightness of each pixel of the projection image including the peripheral pixels is calculated. According to the projection image processing method in which weighting is performed so that the average value becomes a predetermined value, the luminance is not biased to a specific value, and the dynamic range of the signal processing system can be effectively used.

Further, a projection process for extracting a predetermined value set for each pixel from a plurality of image data is executed to generate a projected image, and a histogram of data value and appearance frequency is generated for each pixel of this projected image. According to the projection image processing method in which the luminance value is changed so that the appearance frequency of each luminance in this histogram is constant, the deviation of the appearance frequency of the luminance is eliminated and the dynamic range of the signal processing system can be effectively used. Like

Further, projection processing means for executing a projection process for extracting a predetermined value set for each pixel from a plurality of image data to generate a projection image, and an average brightness of the generated projection image are According to the projection image processing apparatus including the normalization processing unit that adjusts the brightness of the projection image so that the average brightness becomes a predetermined value, the deviation of the brightness is eliminated and the dynamic range of the signal processing system is also increased. You can use it effectively.

Projection processing means for obtaining a projected image by executing a projection process for extracting a predetermined value for each pixel from a plurality of image data, and a brightness value of the average brightness of the projected image is a minimum brightness. According to the projection image processing apparatus provided with the normalization processing means extending to the side and the highest brightness side, the dynamic range of the signal processing system can be effectively utilized.

Projection processing means for obtaining a projection image by executing projection processing for extracting a predetermined value for each pixel from a plurality of image data, and obtaining the average brightness of the generated projection image, A projection image having a normalization unit that adjusts the brightness of the projection image so that the average brightness has a predetermined value, and further expands the brightness value of the average brightness of the projection image to the minimum brightness side and the maximum brightness side. According to the processing device, there is no unevenness in brightness, and the dynamic range of the signal processing system can be effectively utilized.

Projection processing means for executing projection processing for extracting a predetermined value for each pixel from a plurality of image data to generate a projection image, and projection image generated by the projection processing means. According to the projection image processing apparatus including a data value and a histogram of the appearance frequency for each pixel, and a normalization processing unit that changes the value of the brightness so that the appearance frequency of each brightness in the histogram is constant, There is no bias in the appearance frequency of luminance, and the dynamic range of the signal processing system can be effectively used.

Projection processing means for executing a projection process for extracting a predetermined value for each pixel from a plurality of image data to generate a projection image, and a pixel by a region of the generated projection image. According to the projection image processing apparatus provided with the normalization processing unit that performs different weighting for each, there is no bias in the brightness depending on the area, and the dynamic range of the signal processing system can be effectively used.

Projection processing means for executing a projection process for extracting a predetermined value for each pixel from a plurality of image data to generate a projection image,
Normalization processing means for differently weighting each of the plurality of image data according to a predetermined image area, and a predetermined value preset for each pixel for the plurality of weighted image data According to the projection image processing apparatus including the projection processing unit that executes the projection processing for extracting the projection image and generates the projection image, the projection image is generated in a state where there is no bias in the brightness depending on the area. The dynamic range can also be used effectively.

Projection processing means for executing a projection process for extracting a predetermined value for each pixel from a plurality of image data to obtain a projection image, and peripheral pixels for each pixel of the projection image. According to the projection image processing apparatus including the normalization processing means that performs weighting so that the average brightness value becomes a predetermined value, the brightness is not biased to a specific value, and the dynamic range of the signal processing system is also effective. You can use it.

Projection processing means for executing a projection process for extracting a predetermined value set for each pixel from a plurality of image data to obtain a projected image, and data value and appearance for each pixel of this projected image. According to the projection image processing apparatus including the frequency histogram and the normalization processing unit that changes the brightness value so that the appearance frequency of each brightness in the histogram becomes constant, the uneven appearance frequency of the brightness is eliminated. The dynamic range of the signal processing system can be effectively utilized.

[0066]

As described in detail above, according to the present invention,
Projection image processing method and projection image processing capable of executing IP processing capable of fully utilizing the display capability of the display unit by executing the normalization processing according to the brightness of the image together with the projection processing so that the brightness of the projection image is not biased The device can be realized.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a configuration of an apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart of the operation of IP processing according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing an example of IP processing.

FIG. 4 is an explanatory diagram illustrating an example of a processing example of IP processing.

FIG. 5 is an explanatory diagram illustrating an example of a processing example of IP processing.

FIG. 6 is an explanatory diagram illustrating an example of a processing example of IP processing.

FIG. 7 is a flowchart of the operation of IP processing according to an embodiment of the present invention.

FIG. 8 is an explanatory diagram illustrating an example of a processing example of IP processing.

FIG. 9 is an explanatory diagram showing a processing state of IP processing.

[Explanation of symbols]

1 data storage 2 IP processing unit 3 Normalization processing unit 4 Display

Continuation of the front page (56) Reference JP-A-6-14923 (JP, A) JP-A-5-324808 (JP, A) JP-A-5-94540 (JP, A) JP-A-5-12432 (JP , A) JP 5-261095 (JP, A) JP 63-11146 (JP, A) JP 6-54833 (JP, A) Actually open 6-31704 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) A61B 8/00-8/15 A61B 5/055 A61B 6/00-6/14 G06T 1/00

Claims (6)

(57) [Claims] 1. A projection process for extracting a maximum value for each pixel is performed on a plurality of image data to generate a projection image, an average brightness of the projection image is obtained, and the average brightness is set to a brightness center value. The method for projecting an image according to claim 1, wherein the image data of the projected image is shifted, and the brightness of the image data is expanded so that the maximum value of the image data becomes the maximum brightness value. 2. A projection process for extracting a minimum value for each pixel is performed on a plurality of image data to generate a projection image, an average brightness of the projection image is obtained, and the average brightness is set to a brightness center value. The method for projecting a projected image according to claim 1, wherein the image data of the projected image is shifted, and the brightness of the image data is expanded so that the minimum value of the image data becomes the minimum brightness value. 3. For each of the plurality of image data, the pixel data is weighted differently depending on the area on the image data to which the pixel belongs, and the maximum value or the minimum value for each pixel is applied to the weighted plurality of image data. A projection image processing method, characterized in that a projection image is generated by performing projection processing for extracting a value. 4. Projection processing means for executing a projection process for extracting a maximum value for each pixel from a plurality of image data to generate a projected image, an average brightness of the projected image is obtained, and the average brightness is a brightness center. And a normalization processing unit that shifts the image data of the projection image so that the image data becomes a value and expands the luminance of the image data so that the maximum value of the image data becomes the maximum luminance value. A characteristic projection image processing device. 5. A projection processing unit for executing a projection process for extracting a minimum value for each pixel from a plurality of image data to generate a projection image, an average brightness of the projection image, and the average brightness being the brightness center. And a normalization processing unit that shifts the image data of the projected image so that the image data becomes a value, and expands the luminance of the image data so that the minimum value of the image data becomes the minimum luminance value. A characteristic projection image processing device. 6. A normalization processing unit for weighting pixel data of each of a plurality of image data depending on a region on the image data to which the pixel belongs, and each pixel for the plurality of weighted image data. And a projection processing unit configured to execute a projection processing for extracting a maximum value or a minimum value for generating a projection image.