JPH04273782A - X-ray fluoroscopic image processor - Google Patents

Abstract

PURPOSE:To fastly obtain a fine X-ray fluoroscopic image by subtracting after an integration image obtained by adding while the corresponding picture element position is matching and an out-of-focus image obtained by adding while the corresponding picture element position is shifted are weighted. CONSTITUTION:Among plural frames, the video signal of an X-ray fluoroscopic image is added while the corresponding picture element position is matched, an integration image is obtained, and it is added while the corresponding picture element position is shifted, the out-of-focus image is obtained, and after these are respectively weighted, subtraction is performed. That is, after the simple integration and shift integration in frame memories 5 and 6 are completed, the image data of the integration image and the image data of the out-of-focus image formed by them are weighted by calculators 9 and 10 respectively. These image data after weighting are sent to a subtracter 11 and the corresponding picture element data are subtracted.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to an X-ray fluoroscopic image processing device that performs image processing of X-ray fluoroscopic images obtained by an X-ray TV fluoroscopy system, and in particular, relates to an X-ray fluoroscopic image processing device that processes a plurality of continuous frames obtained under The present invention relates to an X-ray fluoroscopic image processing device that processes images.

0002

[Prior Art] An X-ray TV fluoroscopy system converts an X-ray fluoroscopic image obtained by irradiating X-rays from an X-ray tube into a video signal by combining an image intensifier and a TV camera, and displays the video signal on a TV monitor. send it to the device and display it,
It is something to observe. In this X-ray TV fluoroscopy system, in order to reduce the patient's X-ray exposure, when the X-ray fluoroscopy is finished, the last fluoroscopy image is stored in a frame memory etc. and the end is played back. A so-called last frame memory processing technique is often used, in which the perspective image is displayed even after the image has been captured. At this time, since fluoroscopic images are obtained with a small amount of X-rays and therefore contain a lot of quantum noise, noise reduction processing such as integral processing is often performed when recording and reproducing fluoroscopic images.

0003

However, in the conventional method, only an integral process is performed, so that only a noise reduction effect can be obtained, and the contrast of the image is insufficient. In particular, in areas such as the chest where bright areas such as the lung field and dark areas such as the heart area coexist, it is difficult to read the fine structure that overlaps with both. In such cases, it is desirable to automatically perform contrast processing to clearly display the fine structures that coexist on both sides at the same time, and unsharp masking processing may be considered as such processing, but it has the disadvantage of taking a long processing time. There is.

SUMMARY OF THE INVENTION An object of the present invention is to provide an X-ray fluoroscopic image processing apparatus capable of obtaining a high-contrast unsharp masked image in a short time in which microstructures can be easily observed.

[0005]

[Means for Solving the Problems] In order to achieve the above object, an X-ray fluoroscopic image processing apparatus according to the present invention has the following features:
An integral image is obtained by adding the video signals of an X-ray fluoroscopic image while matching the corresponding pixel positions between multiple frames, and a blurred image is obtained by adding the video signals while shifting the corresponding pixel positions. , is characterized in that these are weighted and then subtracted. Since the creation of an integral image and the creation of a blurred image can be performed simultaneously in parallel, these images can be obtained at high speed, and an unsharp masking image can be created in the same amount of time as conventional integral processing alone. can be obtained.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. In FIG. 1, a video signal of an X-ray fluoroscopic image is sequentially sent frame by frame from a TV camera of an X-ray fluoroscopy TV system (not shown).
This video signal is converted into a digital signal by an A/D converter 2. During normal fluoroscopy, this digital signal is sent to the window processor 3 via the switch 1, which is tilted toward the b side, and undergoes window processing (a type of gradation conversion) in which only a predetermined window of the gradations is emphasized. ). Thereafter, the signal is returned to an analog video signal via the D/A converter 4, and sent to a TV monitor (not shown) for display.

When a perspective switch (not shown) is turned off, the digitized image data is added to the output data of the frame memories 5 and 6 in adders 7 and 8, and then written into the frame memories 5 and 6 again. In other words, even after the fluoroscopy switch is turned off, X-ray irradiation continues for a while and a video signal of the X-ray fluoroscopic image is sent, and the image data is stored in the frame memory 5 as described above. 6 is written.

The addresses of the frame memories 5 and 6 are controlled by a memory address controller 12. Regarding the frame memory 5, when the image data of a new frame is sent to the adder 7, the data at the pixel position corresponding to each pixel is read out. As a result, data is added pixel by pixel while matching the positions of corresponding pixels, and the data after the addition is written into the frame memory 5. Therefore, the image is integrated in the time direction, and an integrated image is formed in the frame memory 5.

On the other hand, the read addresses of the frame memory 6 are shifted in the vertical and horizontal directions. That is, the adder 8 does not add pixel data at a certain position in the input image data and pixel data at the same position in the read image data from the frame memory 6, but adds pixel data at a shifted position. . This makes it possible to perform processing (so-called shift integration) in which the entire image is superimposed in a shifted state, and a blurred image can be created in the frame memory 6.

After the simple integration and shift integration in the frame memories 5 and 6 are completed, the image data of the integral image and the image data of the blurred image formed by these are weighted by multipliers 9 and 10, respectively. These weighted image data are then sent to a subtracter 11, where corresponding pixel data are subtracted from each other. At this time, the output data of the subtracter 11 is sent to the window processor 3 via the switch 1 which is tilted to the a side. The window processing by the window processor 3 is the same as that for fluoroscopy described above, and is then converted back to an analog video signal via the D/A converter 4 and sent to a TV monitor (not shown) for display. The same is true.

Since the blurred image is subtracted from the integral image in this way, unsharp masking processing is performed, and an image with high contrast can be obtained. Moreover, since the creation of the integral image and the creation of the blurred image are performed simultaneously and in parallel, no additional processing time is required compared to the conventional case of only integral processing.

In the above embodiment, unsharp masking processing is performed in so-called last frame memory processing at the end of fluoroscopy, but it is not limited to such last frame memory processing. Such processing can also be performed by, for example.

[0013]

[Effects of the Invention] As described above with respect to the embodiments,
According to the X-ray fluoroscopic image processing apparatus of the present invention, an unsharp masked image can be obtained at high speed, so that an X-ray fluoroscopic image that clearly represents the microstructure that the operator most wants to see can be obtained compared to the conventional integral processing alone. can be obtained in approximately the same processing time.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention.

[Explanation of symbols]

1 Switch 2 A/D converter 3 Window processor 4
D/A converter 5 Integral image frame memory 6
Frame memory for blurred images 7, 8
Adders 9, 10 Multiplier 11 Subtractor

Claims (1)

[Claims] 1. A first integrating means that adds video signals of an X-ray fluoroscopic image while matching corresponding pixel positions between a plurality of frames, and a second integrating means that adds video signals while shifting corresponding pixel positions between a plurality of frames. An X-ray fluoroscopic image processing apparatus comprising an integrating means, a means for weighting the integral results, and a subtracting means for subtracting the weighted integral results.