JPH06275394A - X-ray radioscopy device - Google Patents

Abstract

PURPOSE:To provide an optimum radioscopic image even knowledge and skill for an X-ray are lacked by shading-correcting a radioscopic image, then detecting the frequency characteristic of the correction data and the mean value of a light and shade difference, and thereby controlling the voltage and current of an X-ray tube. CONSTITUTION:An X-ray radioscopic image is detected by a CCD camera 1, and the shading of the image is corrected by a shading correction part 2. Corrected data are inputted into a frequency analysis part 3 and a light and shade difference peak detection part 4 to detect the shape of an image from the frequency characteristic of image data by using a FET at the analysis part 3 and the mean value of the light and shade difference of the image data at the detection part 4. A light and shade characteristic is judged from the frequency characteristic of the image data and the mean value of the light and shade difference by a judgment part 5, and the tube voltage and tube current of an X-ray tube 15 are controlled by an X-ray control part 6 by utilizing the light and shade characteristic to generate an optimum X-ray.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray apparatus, and more particularly, to improving the gradation characteristic of an X-ray fluoroscopic image by a computer system incorporating a frequency analyzer.

[0002]

2. Description of the Related Art In recent years, X-ray generation methods have been diversified and their applications have spread to various fields, and as a means of inspection or analysis indispensable in each industrial field where macro conversion is progressing, an X-ray source is used to detect minute parts. Non-contact sensing for obtaining magnified perspective images has become popular. However, a fine focus X-ray source is generally commercialized and has a short history, and there is a great demand for improvement of an inspection or analysis system using the X-ray source. On the other hand, as a method for capturing a fluoroscopic image of X-rays, a method using an image intensifier (X-ray fluorescence multiplier) and a CCD camera has been attracting attention as shown in FIG. In the figure, 1 is a CCD camera, 7 is a monitor, 10 is an image intensifier, 11 is an X-ray source, 12 is an object to be observed, 13 is a lens, and 14 is a mirror. This system is composed of an image intensifier 10 of 6 to 12 inches and an appropriate CCD camera 1 according to the required image quality (resolution, distinction between moving and still images, etc.), and is easy to handle and has a high resolution. You can get a perspective image,
Defects can be observed based on the difference in gray level of the fluoroscopic image. here,
The gray level difference is the difference in the amount of X-rays transmitted to the object to be observed, and is determined by the material and state of the object to be observed, the wavelength of X-rays that pass therethrough, and the quality of the X-rays. Therefore, in order to obtain the grayscale difference, by changing the material of the X-ray target so that X-rays are easily absorbed (or difficult to be absorbed) by the observed object, or by changing the tube voltage and tube current value of the X-ray tube, The wavelength, intensity, and quality of X-rays are set to optimum conditions to obtain a clear contrast.

[0003]

However, in order to obtain the optimum grayscale characteristics in the conventional X-ray apparatus, it is necessary to change the delicate characteristics different for each X-ray generator and the target material and the material of the object to be observed. It is necessary to experimentally find the optimum tube voltage and tube current value. In such a case, the operator needs some physical knowledge and skill. The present invention has been made in view of the above circumstances, and obtains a perspective image having a grayscale characteristic that is optimal even for a person who does not have the above-mentioned elements for an operator X
An object is to provide a line device.

[0004]

In order to achieve the above object, the present invention performs frequency analysis on a fluoroscopic image input from an image pickup means through shading correction means in frequency analysis means, and at the same time, performs frequency analysis. Optimum by detecting the difference in gray level by means of detecting the average value of gray level difference, and further determining and storing the characteristics of the X-ray fluoroscopic image by the determining means and changing the tube voltage and tube current of the X-ray tube by the X-ray control means. It is characterized in that various tube voltages and tube current values are searched for by computer control and optimum X-rays are emitted.

[0005]

According to the present invention, the perspective image obtained by the image pickup means is corrected by the shading correction means due to the shading due to the distortion of the image intensifier, and then the corrected data is obtained by the frequency analysis means and the mean difference detection unit. By detecting the frequency characteristic and the value of the grayscale difference, the grayscale characteristic of the X-ray fluoroscopic image can be examined. Utilizing this, the grayscale characteristics when the intensity and the quality of X-rays are sequentially changed are detected and stored, the optimum tube voltage and tube current values are searched for, and the optimum fluoroscopic image is obtained.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of the X-ray apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an X according to the present invention.
The same or similar means as those of the general X-ray fluoroscopic image capturing method shown in FIG. The operation of the image intensifier shown in FIG. 3 is omitted here, and the CCD
The functions of the camera, monitor, lens, and mirror are also omitted. In FIG. 1, the X-ray fluoroscopic image is a CCD camera 1.
The shading correction unit 2 corrects the shading of the image. The corrected data is input to the frequency analysis unit 3 and the grayscale difference average detection unit 4, and in the former, the frequency analysis unit 3, the frequency of the image data corrected using FFT (Fast Fourier Transform). The shape of the image is detected from the characteristics, and in the latter, the grayscale difference average detection unit 4 detects the average grayscale difference value of the corrected image data.
Here, FIG. 2 shows the relationship between the shape 8a of the image data, that is, the perspective image data expressed in time, and its frequency characteristic 8b, that is, the perspective image data expressed in frequency. The frequency characteristic of the image data thus detected and the average value of the gray level difference are taken into consideration in the determination section 5 to determine the gray level characteristic. Next, this is stored, and the tube voltage and tube current value of the X-ray tube 15 are sequentially changed in the X-ray controller 6 based on this data, and the same determination is repeated. After making a certain determination by this, the determination unit 5 finds the tube voltage and the tube current value when the optimum light and shade characteristics are obtained, and sets them to generate the optimum X-ray.

[0007]

As described above, according to the X-ray image fluoroscope according to the present invention, an operator does not have the physical knowledge and skill of X-rays, and the unknown physical properties are unknown. It is possible to obtain an agile and clear X-ray fluoroscopic image of the object to be observed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of an X-ray image processing system according to the present invention.

FIG. 2 is an explanatory diagram of time expression and frequency expression of a perspective image.

FIG. 3 is a system diagram of a general fluoroscope.

[Explanation of symbols]

 1 CCD camera 2 Shading correction unit 3 Frequency analysis unit 4 Average difference detection unit 5 Judgment unit 6 X-ray tube control unit 7 Monitor 10 Image intensifier 11 X-ray source 12 Observed object 13 Lens 14 Mirror 15 X-ray tube

Claims (1)

[Claims] 1. An X-ray transmission image is picked up by an image pickup means, shading correction is performed, and then this data is subjected to frequency analysis to detect the average value of the characteristics of the transmission image and the grayscale difference of the entire fluoroscopic image. The tube voltage of the X-ray tube from the relationship between the average value of the density difference and the characteristics of the transmission image and the quality and intensity of the X-ray,
An X-ray fluoroscopic device characterized by controlling a tube current value.