KR20100040652A - Apparatus and method for image processing - Google Patents

Abstract

PURPOSE: An image processing device and a method thereof are provided to generate high contrast X-ray image which has improved contrast about not only hard tissue but also soft tissue. CONSTITUTION: A multiple narrow band image acquisition unit(110) comprises a X-ray generating unit, a filter unit, and a X-ray detecting unit. The multiple narrow band image acquisition unit acquires a plurality of X-ray images by using a X-ray corresponding to a plurality of energy bands. A first processing unit(120) generates a plurality of material images by using a plurality of X-ray images. A second processing unit(130) generates a high contrast X-ray image by using at least one among a plurality of material images.

Description

Image processing apparatus and method {APPARATUS AND METHOD FOR IMAGE PROCESSING}

Embodiments of the present invention relate to an image processing apparatus and method, and more particularly, to an apparatus and method for acquiring an image of each substance, a characteristic image, and an anatomical image using a plurality of X-ray images corresponding to multiple narrow band energy bands. It is about.

X-rays were discovered by Roentgen in 1895 and have been used in a variety of industrial and medical applications for medical imaging, security screening imaging, and non-destructive testing.

Since each material has a unique attenuation rate for X-rays, X-ray images can be made by measuring the detected intensity through the X-rays. Typically, hard tissues such as bones and metals of the human body have a high X-ray absorption rate, and soft tissues such as water and fat have a low X-ray absorption rate.

On the other hand, X-rays have different absorption rates according to energy bands (or wavelengths) for each material. In general, when the energy band of the X-ray is low, the difference in absorption rate is large.

Existing X-ray images use wide energy polychromatic X-rays with wide energy bands. Therefore, the contrast of hard tissue is relatively high in X-ray image, but the contrast of soft tissue is low. In addition, the thickness of the material transmitting the X-ray also affected the X-ray image.

Therefore, interest in X-ray imaging with high contrast for soft tissues as well as hard tissues is steadily increasing.

Some embodiments of the present invention are to provide an image processing apparatus and method for generating a high-contrast X-ray image with improved contrast to soft tissue as well as hard tissue.

Another embodiment of the present invention is to provide an image processing apparatus and method for generating a characteristic image or an anatomical image by acquiring an X-ray image divided for each material and performing image processing based on the same.

According to an embodiment of the present invention, an image acquisition unit for acquiring a plurality of X-ray images using X-rays corresponding to each of a plurality of different energy bands, by using the plurality of X-ray images, A first processing unit for generating a plurality of material images, and a second processing unit for generating a high intensity X-ray image using at least one or more of the plurality of material images is provided.

According to an embodiment of the present disclosure, the image acquisition unit may include an X-ray generator that generates wideband X-rays and X-rays corresponding to each of the plurality of different energy bands by filtering the wideband X-rays. A filter unit for providing a line, and an X-ray detector for detecting the X-ray corresponding to each of the plurality of different energy bands passing through the filter unit to obtain the plurality of X-ray images.

According to another embodiment of the present invention, the image acquisition unit, an X-ray generating unit for generating a wideband X-ray, the wideband X-rays by refracting X- corresponding to each of a plurality of different energy bands And a X-ray detector for detecting the X-rays corresponding to each of the plurality of different energy bands passing through the spectroscope, and obtaining the plurality of X-ray images.

According to another embodiment of the present invention, the image acquisition unit, the X-ray generating unit for generating a wideband X-ray, and X-rays passing through the subject by detecting a plurality of different energy bands to each other And an X-ray detector for acquiring a plurality of X-ray images corresponding to each of the other plurality of energy bands.

Meanwhile, the first processor may select at least m (but m is a natural number) X-ray images of the plurality of X-ray images and analyze the selected at least m X-ray images by pixel unit. m material images may be generated.

In this case, the second processor acquires at least two independent component images by performing independent component analysis using pixel values of at least two substance images of the m substance images, and performs the independent component analysis. The high contrast X-ray image may be generated by combining component images. According to some embodiments of the present disclosure, the second processing unit may remove noise, enhance contrast, and perform the independent component analysis. And at least one of edge enhancement.

On the other hand, according to another embodiment of the present invention, the second processing unit, by using at least two material images of the m material images, a characteristic image in which a specific portion of the ratio between the materials is outside the normal range is identified Create

The m substance images may include, for example, a water image, a fat image, a protein image, and an ash image.

In this case, the second processor uses the water image and the fat image to identify a portion in which the ratio of water and fat deviates from a normal value as a specific portion, and distinguishes the color or contrast of the specific portion from other portions. A characteristic image may be generated.

According to another embodiment of the present invention, an image acquisition unit for acquiring a plurality of X-ray images using X-rays corresponding to each of a plurality of different energy bands, and among the plurality of X-ray images A third processing unit which performs at least two independent component images by performing independent component analysis using pixel values of at least two X-ray images, and combines the independent component images to generate a high intensity X-ray image; Provided is an image processing apparatus comprising a.

According to another embodiment of the present invention, obtaining a plurality of X-ray images using X-rays corresponding to each of a plurality of different energy bands, by using the plurality of X-ray images, Generating a plurality of material images, and generating a high illuminance X-ray image using at least one of the plurality of material images.

The acquiring of the plurality of X-ray images may include generating wideband X-rays and filtering the wideband X-rays to provide X-rays corresponding to each of the plurality of different energy bands. And sensing the X-rays corresponding to each of the filtered plurality of energy bands to obtain the plurality of X-ray images.

The generating of the plurality of material images may include selecting at least m (where m is a natural number) X-ray images of the plurality of X-ray images, and the selected at least m X-ray images. And analyzing m pixel by pixels to generate m material images.

According to an embodiment of the present invention, the generating of the high intensity X-ray image may include performing independent component analysis using pixel values of at least two material images of the m material images generated. ), And combining the at least one independent component image obtained through the independent component analysis to generate a high-contrast X-ray image.

On the other hand, according to another embodiment of the present invention, generating the high-contrast X-ray image, using at least two material images of the m material images generated, the ratio between the materials is outside the normal range Calculating a singular part, and generating an image identified as the singular part by adjusting a color or brightness value of the calculated singular part.

The m substance images may include a water image, a fat image, a protein image, and a skeletal image.

In this case, generating the high-contrast X-ray image may include calculating a degree to which the ratio of water and fat deviates from a normal value by using the water image and the fat image, and color the calculated specific portion. Alternatively, the method may include generating an image identified as the singular part by adjusting the brightness value.

Meanwhile, according to another embodiment of the present invention, obtaining a plurality of X-ray images using X-rays corresponding to each of a plurality of different energy bands, and at least one of the plurality of X-ray images Performing independent component analysis using pixel values of two or more X-ray images, thereby obtaining at least two independent component images, and combining the independent component images to generate a high-contrast X-ray image. An image processing method is provided.

According to some embodiments of the invention, the contrast of the X-ray image for soft tissue is improved.

According to another exemplary embodiment of the present invention, a divided X-ray image for each material may be obtained using a multi-narrow energy X-ray image, and a characteristic image or an anatomical image is generated by performing image processing based on the material. Can be.

Hereinafter, some embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited or limited by the embodiments. Like reference numerals in the drawings denote like elements.

1 illustrates an image processing apparatus according to an embodiment of the present invention.

The image acquisition unit 110 acquires a plurality of X-ray images using X-rays corresponding to each of a plurality of different energy bands.

According to an embodiment of the present invention, the image acquisition unit 110, an X-ray generating unit for generating a wideband (Polychromatic X-rays), and filtering the polychromatic X-rays of the plurality of different energy bands A filter unit for providing a corresponding X-ray, and an X-ray for detecting the X-rays corresponding to each of the plurality of different energy bands passing through the filter unit to obtain the plurality of X-ray images It includes a sensing unit.

However, according to another embodiment of the present invention, the image acquisition unit 110, the X-ray generating unit for generating a polychromatic X-ray, each of the plurality of different energy bands by refracting the wideband X-ray X-ray detection for obtaining the plurality of X-ray images by detecting the X-ray corresponding to each of the spectroscopic section for separating the X-ray corresponding to the plurality of different energy bands passing through the spectroscopic section Contains wealth.

In addition, according to another embodiment of the present invention, the image acquisition unit 110, the X-ray generating unit for generating a wideband X-ray, and the X-ray passing through the subject for each of a plurality of different energy bands By detecting by dividing, X-ray detection unit for obtaining a plurality of X-ray images corresponding to each of a plurality of different energy bands.

An example of the X-ray detector is, for example, a quantum counting X-ray detector. The quantum coefficient X-ray detector includes an X-ray detector and a read-out circuit connected through bump bonding.

In this case, the X-ray detector applied with the reverse voltage reacts with the incident X-ray to generate an electron-hole pair, and the generated charge is transferred to the preamplifier of the read-out circuit so as to correspond to the voltage. Will output a signal.

Then, the voltage signal output from the amplifier is transmitted to the comparator and compared with any threshold voltage controlled by external system to output a digital signal of '1' or '0', and finally the counter Count the number of '1's and output the data in digital form.

Since electron-hole pairs are proportional to the energy of the incident X-ray photon, images of different energies can be obtained simultaneously with a single polychromatic X-ray exposure using multiple threshold voltages and energy-specific counters.

That is, in this case, the X-ray detector generates a plurality of X-ray images corresponding to the plurality of energy bands by using the polychromatic X-rays passing through the subject.

More detailed configuration of the image acquisition unit 110 will be described later in more detail with reference to FIGS. 3 to 4.

The first processor 120 generates a plurality of material images by using the generated plurality of X-ray images. According to an embodiment of the present invention, the substance image may be an image relating to water, fat, protein, bone, and the like.

More detailed configuration of the first processing unit 120 will be described later in more detail with reference to FIG. 8.

The second processor 130 generates a high illuminance X-ray image using at least one of the plurality of material images provided from the first processor.

The high illuminance X-ray image may be a characteristic image that calculates and displays a specificity (deviation from the normal range) using a ratio of each material.

According to an embodiment of the present invention, the characteristic image is an image in which the specificity is represented by a difference in color or brightness values. However, the present invention is not limited thereto, and the characteristic image may be an image expressed by differentiating a color or brightness value of a portion where the specificity exceeds a predetermined threshold from another portion.

Meanwhile, in another embodiment of the present invention, the high illuminance X-ray image may be an anatomical image having a high contrast level for each organ of the body.

According to an embodiment of the present invention, in order to generate the anatomical image, the second processor 130 may perform independent component analysis using pixel values of at least two or more material images of the plurality of material images. Component Analysis) to obtain at least two independent component images, and combine the independent component images to generate a high intensity X-ray image.

According to another embodiment of the present invention, when the second processing unit 130 generates the feature image, the second processing unit 130 uses at least two material images of the plurality of material images. Thus, the characteristic image is generated to help identify a specific part by quantitatively expressing the degree to which the ratio between the substances deviates from the normal range.

A more detailed process of generating a high illuminance X-ray image using a plurality of material images by the second processor 130 will be described later in more detail with reference to FIG. 9.

Meanwhile, according to another embodiment of the present invention, the image processing apparatus 100 includes a third processing unit (not shown) in place of the first processing unit 120 and the second processing unit 130. . The third processor may perform independent component analysis by using pixel values of at least two or more images of the plurality of X-ray material images generated by the image acquisition unit, without using an image for each material. By doing so, at least two independent component images may be obtained, and the independent component images may be combined to generate a high intensity X-ray image. This content will be described later in more detail with reference to FIGS. 7 and 9.

Meanwhile, the display unit visually displays the high illuminance X-ray image provided by the second processor 130. The display unit may be, for example, an imaging device including an LCD panel. However, this is only an example, and the configuration of the display unit 140 may be various applications such as electronic devices and printing equipment.

FIG. 2 shows an exemplary graph of X-ray attenuation coefficients by material according to energy bands of X-rays.

The X axis of the graph represents the energy of the X-rays. The larger the X-ray energy value, the shorter the wavelength. And the Y axis of the graph shows the attenuation rate of X-rays.

The decay rate curves 210 to 240 decay rate curves 240 each represent the X-ray decay rates of materials K ₁ to K _{m as} the energy of the X-rays increases. As can be seen from the curves 210 to 240, as the energy value of the X-ray increases, the transmittance tends to be large and the attenuation tends to decrease.

However, depending on the material, the X-ray attenuation rate may decrease as the energy of the X-ray increases, and may have an edge in which the attenuation rate rapidly increases in a specific energy band. For example, for the curve 210 of FIG. 2, there is an edge where the attenuation rate of the X-rays has a sharp change. This part is also commonly referred to as K-Edge, which is a part of the photon energy that is just above the binding energy of the K shell. This is because the attenuation coefficient of the photon rapidly increases.

Since the curves 210 to 240 corresponding to the material K ₁ to K _m exhibit a specific attenuation rate, using this information, a plurality of X-ray images corresponding to a plurality of narrow band energy bands (multiple monochromatic) By using, material images may be obtained.

3 shows a comparison of the energy distribution of Polychromatic X-rays and Monochromatic X-rays.

Curve 310 of graph (a) shows the energy distribution of the Polychromatic X-rays. X-rays generated in an X-ray generator have various energies. X-ray images obtained by emitting such polychromatic X-rays to an object and sensing through an X-ray detector (such as an X-ray film or an electronic X-ray detector) (especially soft tissue) Low contrast. Therefore, they are often of low value for medical use or for security screening.

In one embodiment of the present invention, by irradiating each of the multiple monochromatic X-rays shown in the graph (b) with a subject, a plurality of X-ray images corresponding to different energy bands are obtained.

Curves 321 to 323 of graph (b) represent energy bands of E ₁ to E _L (where L is a natural number).

According to one embodiment of the invention, for the X-rays having the energy distribution of the curve 310 of the graph (a), using a band pass filter that selectively passes only the X-rays corresponding to a specific energy band By filtering, multiple monochromatic X-rays having an energy distribution of curves 321 to 323 can be generated.

According to an embodiment of the present invention, the filtering may be performed using a tunable filter. However, the present invention is not limited thereto, and the filtering may be performed using a plurality of filter units passing different energy bands.

Meanwhile, according to another embodiment of the present invention, an X-ray having an energy distribution of the curve 310 of the graph (a) is incident on a crystal slit having a uniform lattice at a constant angle, thereby providing a graph ( It may be separated into X-rays of different energy bands, such as curves 321 to 323 of b). A more detailed description of this embodiment will be described later with reference to FIG. 4.

4 shows a monochromatic X-ray generating apparatus according to an embodiment of the present invention.

The X-ray source 410 generates and irradiates a Polychromatic X-ray 411 having a broadband energy distribution as shown by the curve 310 of FIG. 3 (a).

The spectroscope 420 has a plurality of slits 421 to 423, and each of the slits has a uniform lattice and is disposed with a difference in angle.

When the polychromatic X-rays 411 are reflected at each slit 421 to 423, they are divided into monochromatic X-rays 431 to 433 having different energy bands according to the angle of each slit. This principle is called Bragg's theory.

By introducing the spectroscope 420, the existing X-ray source 410 that generates the polychromatic X-ray 411 can be used as it is, so that the apparatus can be miniaturized and the multiple monochromatic X- can be reduced at a relatively low cost. You can create a line.

When X-ray images of an object are obtained using each of the X-rays 431 to 433 of different energy bands, a plurality of X-ray images corresponding to different energy bands may be obtained. have. Some embodiments of this series of processes are described in more detail below with reference to the drawings.

Meanwhile, according to another embodiment of the present invention, an X-ray having an energy distribution of the curve 310 of the graph (a) using an X-ray detector having an energy discrimination function may be used. Images corresponding to X-rays of different energy bands, such as curves 321 to 323 of b), may be obtained.

FIG. 5 is a conceptual diagram of an exemplary simple human body configuration that can be analyzed as an high illuminance X-ray image through an image processing process according to an embodiment of the present invention.

Portion 500 of the human body may be comprised of, for example, Ash 510, Protein 520, Water 530, and Fat 540. However, the configuration of FIG. 5 may be different from the actual human tissue, and is merely an exemplary assumption.

If an X-ray image of a portion 500 of the human body is obtained using a Polychromatic X-ray having an energy distribution of the curve 310 of Fig. 3A, the skeleton ASH and its The distinction between the other constructs is relatively clear, but the distinction between proteins 520, water 530, and fat 540 (hereinafter also referred to as "soft tissue") is not clear.

However, according to one embodiment of the present invention, for a portion 500 of the human body using multiple monochromatic X-rays having an energy distribution of curves (321 to 323, etc.) of graph (b) of FIG. If a plurality of X-ray images corresponding to different energy bands are acquired, processed to generate material-specific images, and high-contrast X-ray images are obtained using the material-specific images, the distinction between the soft tissues may be clear. Can be.

FIG. 6 shows an exemplary graph of X-ray attenuation coefficients for each material constituting the human body.

The graph shows the curves of the attenuation coefficients for each of the hard bones, muscles, and fats, the difference between the bone and muscle attenuation coefficients (Bone-muscle), and the fat and muscle attenuation coefficients ( Fat-muscle is also shown.

Also shown are the attenuation coefficient curves of certain materials with K-edges, such as iodine. The iodine contrast media is a material that can be utilized for angiography due to the property of having the K-edge.

FIG. 7 illustrates a plurality of X-ray images of the exemplary human configuration of FIG. 5 taken using Multiple Monochromatic X-rays, in accordance with an embodiment of the invention.

The image 710 is an image obtained by photographing the human body 500 using X-rays corresponding to an energy band near 20 Killo eV (keV). The image 720 is an image acquired using X-rays corresponding to an energy band near 25 keV. Also, the image 730 and the image 740 are images obtained by using X-rays corresponding to energy bands near 30 keV and 40 keV, respectively.

As described above with reference to FIG. 2, an image obtained by using an X-ray corresponding to a relatively high energy band has a lower distinction between materials. This is because the higher the X-ray energy, the smaller the difference in X-ray attenuation coefficients between materials.

A process of acquiring an X-ray image for each material using the plurality of images 710 to 740 will be described later with reference to FIG. 8.

FIG. 8 illustrates a plurality of material-specific images generated using the plurality of X-ray images of FIG. 7 according to an embodiment of the present invention.

According to an embodiment of the present invention, images 810 to 840 for each material may be generated using a plurality of images 710 to 740 corresponding to different energy bands of FIG. 7.

If (it will be, assuming a narrow band energy band to approximate a single energy E hereinafter) if N _0-photon (photon) is the line attenuation coefficient m X- (E) consisting of having a single energy E, the thickness T The number N of photons after passing through an object is equal to the following expression (1).

[Equation 1]

N = N ₀ e ^{- μ ( E ) T}

If the type of the material through which the X-rays pass is M, the thickness of the m- th material is T _m , and Equation 1 may be expressed as Equation 2 below.

[Equation 2]

N = N ₀ e- ^{( μ 1 ( E ) T 1+ μ 2 ( E ) T 2+ ... + μM ( E ) TM )}

Based on this equation, the image pixel value is determined by dividing both sides by measurable N ₀ and taking -log. In the same way the L different energies _{E 1, E 2, ...,} E l, ..., pixel (pixel) values I (E _l) obtains the L number of X- ray imaging with respect to the following equation: _L E It can be expressed by Equation 3.

[Equation 3]

I ( E _l ) = -log ( N ( E _l ,) / N ₀ )

= μ ₁ ( E _l ) T ₁ + μ ₂ ( E _l ) T ₂ + ... + μ _M ( E _l ) T _M.

Thus, for each pixel from the intestinal L Monochromatic X- ray images and to obtain L of the equation, such as Equation (3), If this is expressed as a matrix equation as follows.

[Equation 4]

I = μ · T

Therefore, in the case of L = M , the separated image of each material can be obtained by calculating the matrix operation T = μ ^-1 · I. Equation 4 is derived assuming an ideal Monochromatic X-ray image, but can be changed to Equation 4 when using a Quasi-Monochromatic X-ray image having a constant bandwidth.

The number L of monochromatic X-ray images obtained in FIG. 7 is 4, and the number M of substances to be expressed separately is M = 4. Accordingly, four material images 810 to 840 may be generated using the equations (1) to (4).

The substance image 810 is an image in which fats are separated, and the substance image 820 to 840 are images in which water, proteins, and bones are separated from each other.

FIG. 9 illustrates a high illuminance X-ray image of the exemplary human configuration of FIG. 5 generated using the plurality of material-specific images of FIG. 8, in accordance with an embodiment of the present invention.

When the material image 810 to the material image 840 of FIG. 8 are obtained, a high-contrast X-ray image may be generated by reconstructing the material image 810 to suit a purpose.

Various embodiments of the present invention can be applied. For example, the field of security screening, medical imaging diagnostics. In the field of security search, since the purpose is to find a specific substance, the substance image may be used as it is, or a characteristic image using a ratio between substances may be generated and used.

In addition, there may be a number of applications for the field of medical imaging diagnostic medicine, in the present specification, the characteristic image and hard tissue as well as the hard tissue, which distinguishes and displays the portion where the ratio difference of substance is outside the normal range as abnormal tissue. Because of the high contrast, application examples such as anatomical images that anatomically represent organs in the body can be assumed.

According to an embodiment of the present invention, a characteristic image is generated using the substance images 810 to 840 by using a fact that the ratio of substance components between normal tissue and abnormal tissue (for example, lesion tissue such as cancer or fatty liver) is different. do.

For example, in the liver, since the normal fat component reference ratio is 3%, an image expressing a risk level of fatty liver can be made as a ratio of fat component images among all liver components. This may be implemented by comparing each pixel value of an image for each material obtained by the above-described method with reference to FIG. 8 and comparing them with each other.

Meanwhile, according to another exemplary embodiment, the anatomical image 900 may be expressed using the material images 810 to 840. An anatomical image is an image that visually recognizes the shape of an organ in a human body. The ideal form of the anatomical image, the distinction between the organs (organs) is clear, can give an effect as if seeing through the body.

In the human body, four components, water, fat, protein, and lime (bone), account for more than 90% of the total. In the present embodiment, it is assumed that the material ratios are unique to each organ, and the material images are reconstructed into the anatomical images by using the material component ratios of the organs (heart, stomach, liver, lung, intestine, etc.) obtained statistically. do. The specific value of the material component ratio may vary slightly from person to person, but if the statistical representative value is used, the result of the image processing process can be trusted.

In this case, the following equation is established between the material images 810 to 840 and the anatomical image 900.

[Equation 5]

N is the number of substance types for which substance composition ratio information is to be displayed in an anatomical image. And T (p) is a vector of the image material on the pixel _{p [T 1, T 2,} ... , T _m ,… , T _M ] ^T. Here, T _m corresponds to the pixel value of the m-th material image. And O _n ( p ) is the thickness of the nth organ in pixel p , and R ( O _n ) is the material composition ratio of the nth organ [ R ₁ ( O _n ), R ₂ ( O _n ), ..., R _m ( O _n ), ..., R _M ( O _n )] ^T.

Where R _m ( O _n ) means the relative amount of the m th substance of the n th organ. Therefore, the substance image vector is expressed in the form of a linear combination of substance composition ratios for each organ whose thickness value is the coefficient of the organ image. As described above, in relation to the material composition of the organ, if R ( O _n ) is specified using an average value having statistical universality, the determinant of Equation 5 may have a unique solution.

If not, considering the composition ratio of the material in which there is a slight variation in each person, R ( O _n ) cannot be specified, and the determinant of Equation 5 has no unique solution. That is, O _n ( p ) is not uniquely determined.

In this case, assuming that O _n ( p ) is a mixed signal by an independent signal for n, Equation 5 may be regarded as an independent component analysis problem represented by the following equation.

[Equation 6]

x = A s

In Equation 6, x = [ T ₁ , T ₂ , ..., T _M ] ^T , s = [ O ₁ , O ₂ , ..., O _N ] ^T , A = [ R ( O ₁ ) , R ( O ₂ ), ..., R ( O _N )]. Therefore it may determine the O _n (p) with R (O _n) a statistical analysis of the T without precise knowledge of the R (O _n).

However, in all material images, pixels in which only air outside the object having no value may appear may be excluded from the calculation. In the above embodiment, since O _n means an image separated for each organ, an (anatomical) X-ray image of high illumination may be generated.

Meanwhile, in Equation 5, when the m th element T _m of T ( p ) is substituted into Equation 3, the following relationship is obtained.

[Equation 7]

은 장기별 분리영상

과 고유의 상수값인

의 선형 결합으로 표현된다. 이는 수학식 5와 유사한 의미를 가진다.Pixel value of each pixel of the plurality of energy images from Equation (7)

Silver organ separation

And the constants unique to

Is expressed as a linear combination of. This has a similar meaning to the equation (5).

Therefore, the image separated by each organ by omitting the process of obtaining the material-specific image and performing independent component analysis using the pixel values of the plurality of (energy-specific) X-ray images acquired by the image capturing apparatus 110 You can also get

10 shows an example of obtaining an organ separation image to obtain an anatomical X-ray image of high illuminance. (A) to (d) of FIG. 10 are monochromatic X-ray images obtained at different energies, and (e) to (h) are image of each material calculated using (a) to (d).

Also, (i) to (l) are independent component analysis result images. In particular, as shown in (i) to (l), the independent component analysis makes it possible to express the organ structures superimposed on each other separately, so that the shape of the organs is more clearly compared to the above (a) to (d). High contrast X-ray images can be generated that can be observed easily.

The high-contrast X-ray image generated in this way means not only to obtain a high-quality X-ray image with improved visual recognition, but also a contrast agent (for example, the lodine contrast media described above with reference to FIG. 6) when performing vascular imaging. ) Can be said to have great utility value in that the risk of the patient can be greatly reduced.

In addition, when the anatomical high illuminance X-ray image is generated, for example, only the characteristic image regarding the abnormality of the fat ratio may be considered by limiting the inside of the liver part. You can expect great effects from

11 shows a high illuminance X-ray image 1100 of a human body, generated in accordance with one embodiment of the present invention.

Anatomical high illumination X-ray image 1100 is obtained according to the series of processes described above, and as shown, it can be seen that the contrast of soft tissues is improved compared to the existing X-ray images.

However, the image 1100 is merely an exemplary image and is not intended to limit the effects of the image processing method or the image processing apparatus of the present invention. That is, according to the image processing method of the present invention, various kinds of different images may be generated.

In addition, it is also possible to obtain any anatomical image with improved visual recognition by expressing in different colors for each organ.

12 illustrates a characteristic image 1200 of a human body, generated according to an embodiment of the present invention.

In this embodiment, the singular portion 1210 is expressed by using a substance image to display the color of the portion where the percentage of fat exceeds a predetermined threshold (eg, 3%) unlike other portions.

In this embodiment, the color of the singular part 1110 is displayed differently from other parts, but in other embodiments, the contrast may be visually discriminated by changing the contrast.

Also, in another embodiment, an image may be provided as a result of displaying the degree of fat (specificity) as a color difference or a contrast difference without extracting the specific part separately. In this case, the specificity value may be a contrast value of the resultant image.

13 illustrates an image processing method according to an embodiment of the present invention.

In operation S1310, a plurality of X-ray images are obtained by using multiple monochromatic X-rays corresponding to different energy bands.

According to an embodiment of the present invention, in step S1310, multiple monochromatic X-rays may be generated by generating polychromatic X-rays, filtering them, or reflecting and separating them at different angles. This filtering or spectroscopic process is as described above with reference to FIG. 3 or 4.

In addition, a plurality of X-ray images (for example, images 710 to 740 of FIG. 7) are generated by irradiating the object with multiple monochromatic X-rays corresponding to different energy bands thus generated and sensing the irradiated X-rays. ) May be generated.

According to one embodiment of the present invention, in step S1320, various post processing may be performed. For example, a preprocessing process such as noise reduction, edge enhancement, and contrast adjustment may be performed on the plurality of X-ray images generated in step S1310. This preprocessing (also commonly referred to as image processing in the sense) can improve the quality of image processing at a later stage.

In operation S1330, a plurality of material-specific images are acquired. This process may be performed using Equations 1 to 4, and a more detailed process is as described above with reference to FIG. However, according to another embodiment of the present invention, when the high-contrast X-ray image is obtained using the plurality of X-ray images (that is, the process of obtaining a material-specific image is omitted) Is omitted.

In operation S1340, a high luminance X-ray image may be obtained by recombining the image in pixel units.

According to an embodiment of the present invention, the high illuminance X-ray image is a characteristic image. However, in another embodiment of the present invention, the high illuminance X-ray image may be an anatomical image.

In each case, a detailed process of recombining an image in pixel units is as described above with reference to FIG. 9 through Equations 5 to 6.

In addition, an image recombination process in the case of obtaining a high-contrast X-ray image from the plurality of X-ray images without omitting a material image is omitted, as described above with reference to Equation (7).

In step S1350, the high illuminance X-ray image is displayed. In this process, as described above, the contrast and / or the color may be expressed differently for each organ, or in the case of the characteristic image, the visual differentiation may be made by changing the contrast and / or the color of the specific part.

FIG. 14 illustrates an image processing method performed after step S1330 of FIG. 13 to generate an anatomical high illumination X-ray image using a plurality of material-specific images in an image processing method according to an embodiment of the present invention. do.

In step S1410, the material image acquired in step S1330 is analyzed to form a sample vector for each material ( T ( p ) of Equation 5) for the plurality of pixels. As described above, when the step S1330 is omitted because a plurality of X-ray images are used without acquiring images of materials, a plurality of (energy-specific) X-ray images are used as the input.

In operation S1420, independent component analysis of Equation 6 is performed, and in operation S1430, an individual component image for each organ may be generated by constructing an independent component image corresponding to O _n ( p ). That is, O _n ( p ) and R ( O _n ) in Equation 6 may be determined. In operation S1440, only component images that match the purpose of the final image are selected from the component images for each organ.

Method according to an embodiment of the present invention is implemented in the form of program instructions that can be executed by various computer means may be recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the claims below but also by the equivalents of the claims.

1 illustrates an image processing apparatus according to an embodiment of the present invention.

Figure 2 shows an exemplary graph of the X-ray attenuation rate by material according to the energy band of the X-rays.

3 shows a comparison of the energy distribution of Polychromatic X-rays and Monochromatic X-rays.

4 shows a monochromatic X-ray generating apparatus according to an embodiment of the present invention.

FIG. 5 is a conceptual diagram of an exemplary human body configuration that may be analyzed as an high illuminance X-ray image through an image processing process according to an embodiment of the present invention.

6 shows an exemplary graph of the X-ray attenuation rate for each material constituting the human body.

FIG. 7 illustrates a plurality of X-ray images of the exemplary human configuration of FIG. 5 taken using Multiple Monochromatic X-rays, in accordance with an embodiment of the invention.

FIG. 8 illustrates a plurality of material-specific images generated using the plurality of X-ray images of FIG. 7 according to an embodiment of the present invention.

FIG. 9 illustrates a high illuminance X-ray image of the exemplary human configuration of FIG. 5 generated using the plurality of material-specific images of FIG. 8, in accordance with an embodiment of the present invention.

FIG. 10 illustrates a result of generating a plurality of material-specific images using a plurality of energy-specific images and generating a plurality of independent component analysis result images using the plurality of material-specific images according to an embodiment of the present invention. do.

11 shows a high contrast X-ray image of a human body, produced in accordance with one embodiment of the present invention.

12 illustrates a characteristic image of a human body, generated according to an embodiment of the present invention.

13 illustrates an image processing method according to an embodiment of the present invention.

FIG. 14 illustrates a process of generating a high illuminance X-ray image using a plurality of material-specific images in an image processing method according to an embodiment of the present invention.

Claims (20)

An image acquisition unit acquiring a plurality of X-ray images using X-rays corresponding to each of a plurality of different energy bands; A first processor configured to generate a plurality of material images using the plurality of X-ray images; And A second processor configured to generate a high illuminance X-ray image using at least one of the plurality of material images; Image processing apparatus comprising a. The method of claim 1, The image acquisition unit, An X-ray generator for generating wideband X-rays; A filter unit for filtering the wideband X-rays to provide X-rays corresponding to each of the plurality of different energy bands; And X-ray detection unit for detecting the X-ray corresponding to each of the plurality of different energy bands passing through the filter unit to obtain the plurality of X-ray images Image processing apparatus comprising a. The method of claim 1, The image acquisition unit, An X-ray generator for generating wideband X-rays; A spectroscopic unit refracting the broadband X-rays and separating the X-rays into X-rays corresponding to each of a plurality of different energy bands; And X-ray detection unit for detecting the X-rays corresponding to each of the plurality of different energy bands passing through the spectroscope to obtain the plurality of X-ray images Image processing apparatus comprising a. The method of claim 1, The image acquisition unit, An X-ray generator for generating wideband X-rays; And X-ray detector for acquiring a plurality of X-ray images corresponding to each of a plurality of different energy bands by using the broadband X-ray Image processing apparatus comprising a. The method of claim 1, The first processor may select at least m (but m is a natural number) X-ray images of the plurality of X-ray images, analyze the selected at least m X-ray images by pixel, and perform m An image processing apparatus, comprising generating a substance image. The method of claim 5, The second processor may be further configured to perform at least one independent component analysis by performing independent component analysis using pixel values of at least two material images of the m material images, and obtain the at least one independent component image. And a high intensity X-ray image in combination. The method of claim 6, And the second processor is configured to perform at least one of preprocessing of noise removal, contrast enhancement, and edge enhancement before performing the independent component analysis. The method of claim 5, And the second processor generates a characteristic image in which a specific portion in which a ratio between substances is out of a normal range is identified using at least two substance images of the m substance images. The method of claim 5, The m substance images include a water image, a fat image, a protein image, and an ash image. 10. The method of claim 9, The second processor may identify a portion having a ratio of water and fat out of a normal value as a specific portion using the water image and a fat image, and distinguish a color or contrast of the specific portion from other portions to generate a characteristic image. An image processing apparatus, characterized in that the generation. An image acquisition unit acquiring a plurality of X-ray images using X-rays corresponding to each of a plurality of different energy bands; And Among the plurality of X-ray images, at least one independent component image may be obtained by performing independent component analysis using pixel values of at least two X-ray images, and the high-intensity X-rays may be combined by combining the independent component images. Third processing unit for generating an image Image processing apparatus comprising a. Obtaining a plurality of X-ray images using X-rays corresponding to each of a plurality of different energy bands; Generating a plurality of material images using the plurality of X-ray images; And Generating a high illuminance X-ray image using at least one of the plurality of material images Image processing method comprising a. The method of claim 12, Acquiring the plurality of X-ray images, Generating a broadband X-ray; Filtering the wideband X-rays to provide X-rays corresponding to each of the different plurality of energy bands; And Acquiring the plurality of X-ray images by detecting X-rays corresponding to each of the filtered plurality of energy bands Image processing method comprising a. The method of claim 12, The generating of the plurality of material images may include: Selecting at least m (where m is a natural number) X-ray images of the plurality of X-ray images; And Generating m material images by analyzing the selected at least m X-ray images in pixel units Image processing method comprising a. The method of claim 14, Generating the high illuminance X-ray image, Performing independent component analysis by using pixel values of at least one material image among the generated m material images; And Generating a high intensity X-ray image by combining at least one independent component image obtained through the independent component analysis Image processing method comprising a. The method of claim 14, Generating the high illuminance X-ray image, Calculating a degree of singularity in which a ratio between materials deviates from a normal range by using at least two material images of the m material images generated; And Generating an image identified as the singular part by adjusting the calculated color or brightness value of the singular part; Image processing method comprising a. The method of claim 14, The m substance images include a water image, a fat image, a protein image, and an ash image. The method of claim 17, Generating the high illuminance X-ray image, Using the water image and the fat image, detecting a portion where the ratio of water and fat deviates from a normal value; And Generating an image identified as the singular part by adjusting a color or brightness value with the detected singular part Image processing method comprising a. Obtaining a plurality of X-ray images using X-rays corresponding to each of a plurality of different energy bands; Performing independent component analysis using pixel values of at least two X-ray images among the obtained plurality of X-ray images; And Generating a high intensity X-ray image by combining at least two independent component images obtained through the independent component analysis Image processing method comprising a. The method according to any one of claims 12 to 19, And a computer program for recording the computer program for performing the image processing method.

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