JPS61126545A - Image processor - Google Patents

Abstract

PURPOSE:To form two processed images which differ in contrast on one recording material by providing an arithmetic function which calculates two unsharp mask signals, and performs a frequency emphasizing process and a gradation process for both respectively and sends two processed images out at the same time. CONSTITUTION:When an unsharp mask signal Sus is calculated, the arithmetic function which calculates two unsharp mask signals Sus1 and Sus2 by setting two kinds of mask sizes and performs the frequency emphasizing process and gradation process for those unsharp mask signals Sus1 and Sus2 to send two processed image data out to the recording material at the same time is provided. Namely, a computing element 10 processes processing pixel data for a parameter N1 to calculate the unsharp mask signal Sus1 and carries out a subtraction process, multiplication process, frequency emphasizing process, and gradation process in order. Further, the computing element calculates the unsharp mask signal Sus2 corresponding to coordinates for process pixel data for a parameter N2 and then performs the subtraction process, multiplication process, frequency emphasizing process, and gradation process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an image processing device in a radiographic system used for medical diagnosis.

[Technical pre-invention r! A] An example of an X-ray photography system among radiography systems will be described with reference to FIG.

This X-ray photography system consists of an X-ray imaging device 1 that has a phosphor plate that irradiates XwA onto a subject and stores XLL transmitted through the subject as energy for an X-ray image.
Then, the phosphor plate is scanned with excitation light having a wavelength of 500 to 800 nl, and the energy stored in the phosphor plate is excited from its traps to emit light having a wavelength of 300 to 500 nm. A photodetector (for example, a photomultiplier tube) configured to receive only light in that wavelength range.

After reading the X-ray image by the X-ray image reading device 2, the output signal of the photodetector is non-linearly amplified, and then an A/D converter is used. Perform frequency emphasis processing and gradation processing as necessary on the simulated signal converted to a digital signal.
The image processing device 3 stores the results in a storage means such as an image memory, and the image data stored in the iris image memory.

- an X-ray image reproducing device 4 that sequentially reads out the X-ray image data and converts it into an analog signal using a D/A converter, and further inputs the X-ray image data into an optical recording light source amplified by an amplifier to convert the X-ray image data into an optical signal; It is equipped with an X-ray image recording device 5 that inputs a signal through a lens system and irradiates it onto a recording material such as a photographic film to form an X-ray image on the recording material,
The X-ray image formed on the recording material is observed and used for diagnosing the subject.

A conventional example of the image processing device 3 in such an X-ray photography system is shown in FIG.

This image processing device 3 includes a buffer 7 memory 6 connected to the image data and control bus and storing Xa image data;
The image processor 7 is connected to the CPIJ bus and performs frequency emphasis processing and two-gradation processing on the X-ray image data stored in the buffer 7 memory 6 in accordance with commands sent from the CPLI via the CPU bus. There is.

Next, an algorithm for Xa image processing by this image processing device 3 will be explained.

This algorithm is executed by arithmetic processing according to the following equation (1).

S-7[SO+β(S o-8us) ] ---
-(1) Here, SO is the original image signal read out from the phosphor plate of the X-ray image reading device 2, and 3us is a non-sharp mask signal (so that the original image contains only frequency components lower than extremely low frequency components). It is a blurred unsharp image @ (hereinafter referred to as [unsharp mask J], which means the signal of each scanning point), and can be expressed as 3us=4゜1, J S i, j / N 2 .

In addition, β is an emphasis coefficient for extremely low frequency components, γ is a gradation coefficient, and N
is a parameter (mask size).

In the above formula (1), [SOFβ(So −3us)
The second calculation process is known as frequency emphasis processing,
Further, the arithmetic processing of γ[So-β(So-8O3)] is known as gradation processing that is performed by accessing the γ table on the xam fine data that has been subjected to frequency emphasis processing. (Refer to Japanese Patent Application Laid-Open No. 56-75139).

The image processing step of X-ray image data based on such an algorithm is performed in the X1 image shown in FIG. Further details will be given with reference to an explanatory diagram showing a microprogram stored in advance in the image processor 7 and an explanatory diagram showing a microprogram stored in advance in the image processor 7 shown in FIG.

In addition, in Figure 8, 1. j is a pixel number indicating the coordinates of each scanning point.

First, the initial setting start command is sent from the CPU to the CPU.
It is sent to the image processor 7 via the bus, and from this the image processor 7 lets internal disturbance parameters (emphasis coefficient β1 gradation coefficient γ, mask size N) according to the processing information from the control console (not shown). .

After completing this set, the image processor 7 continues to hold the next command of the microprogram, the processing start command, at the same program count position on the microprogram.

During this time, the microprogram is in a hold state.

Next, the CPU checks the preparation status of the peripheral equipment of this X-ray photography system, and sends a processing start command to the image processor 7 when the preparation is complete. As a result, the image processor 7 reads out the xm image data stored in the buffer 7 memory 6, and starts arithmetic processing based on the equation (1).

This arithmetic processing is continuously executed for each pixel 0 of the non-sharp mask based on the processing steps on the microprogram, and the processed pixel data is temporarily stored in the buffer 7 memory 6.

In order to continuously perform such arithmetic processing and output of processed pixel data for each pixel, a store (r tJ SH) command and a return command are provided on the microprogram. By setting the number of pixels per line in advance as this store command, the image processor 7 continuously performs arithmetic processing and outputs the processed data by the set number, and these processes are performed. Upon completion, the microprogram is loaded (POP) to return to the original flow.

When the pixel processing for one line is completed as described above, the next line's pixel processing is started by the line switching command, and the same goes for the pixel data p! Vixel processing is performed up to the pixel data of the sliding door, that is, S(1°j).

Note that the time required for line switching is negligible compared to the time required for pixel processing.

In this way, the vixel processing is performed in the image processing device 3, and two types of emphasis coefficients β1. Frequency emphasis processing and gradation processing are performed using β2 and two types of gradation coefficients γ1 and T2.
Furthermore xIIIiii! ilI! The storage device 5 performs 2vA processing li! on the recording material X1 with different emphasis coefficients β and gradation coefficients γ as shown in FIG. ii image AI, at.

[Problems with Background Art] In the conventional device described above, as shown in FIG.
When processing the pixel data of the point 2) using the parameters of the NXN unsharp mask, the image processor 7 uses the coordinate S(i.

The unsharp mask signal 3us in the equation (1) can be calculated only after the vixel processing of the pixel data p in j) is completed, and based on this calculation result, two types of emphasis coefficients β1. β2.
Two types of lI! i harmonic coefficient γ1. γ2 is used to perform frequency emphasis processing and one gradation processing, resulting in two processed images A1.81 on one sheet of recording material Xt as shown in FIG.
is formed.

However, in this case, since the parameters of the non-sharp masks for the processed images Ar and St formed on one sheet of recording material Xt are both N, the contrast of the immediate image A1.8t on both sides is the same, and , these two paintings (iAt,
If you want to make the Bt contrast different, use 21! Buffer memory of 211111 and image processor of 211111 are required, so what is the configuration of the image processing device? I
There was a problem that processing efficiency and throughput deteriorated as the system became more advanced.

[Object of the Invention] The present invention has been made in view of the above circumstances, and it is an object of the present invention to form two processed images with different contrasts on a single sheet of recording material while having substantially the same circuit configuration as a conventional device. It is an object of the present invention to provide an image processing apparatus that can improve diagnostic performance and improve processing efficiency and throughput.

[Summary of the invention j 11 of the present invention to achieve the above object! ! In short, when forming a visible image on a recording material based on radiographic image data obtained by passing through a subject in a radiographic system, a non-sharp mask signal of 3 us corresponding to each pixel data of the radiographic image data is used. When the original image signal of the radiation image data is So, the emphasis coefficient is β, and the gradation coefficient is γ, the following calculation is performed to apply frequency emphasis processing and Processing li with gradation processing! In an image processing device that can send i-image data,
To obtain S us, two different mask sizes are set and two unsharp mask signals 3usl and 5u are generated.
Find s2 and calculate these non-sharp mask values @SL+51,
It does not include a calculation function that can perform frequency emphasis processing and gradation processing on each of the 5usz and send two processed image data simultaneously to the recording material, and two different pieces of image data for the same image on one recording material. It is characterized by making it possible to visually recognize images with contrast.

[Embodiments of the invention] Examples of the present invention will be described in detail below.

FIG. 1 is a block diagram showing the configuration of an image processing device 3A of this embodiment, which processes xtsm image data stored in a buffer memory 6△ and this buffer 1 memory 6A similar to the conventional device according to an image processing algorithm. , and CP
The image block [1t! It is equipped with Tsusa 7A.

As shown in FIG. 2, the image processor 7A includes a microprogram memory in which a processing microprogram is stored in advance, and a vibe line register (hereinafter referred to as "microprogram") for sending out a microcode (one instruction of the processing microprogram). (referred to as program memory J) 8, a sequencer that accesses the microprogram memory 8 and controls the processing microprogram by commands sent from the CPU via the CPU bus, and a microprogram that receives the instruction address sent from the sequencer 9. It is composed of a processor 10 that executes calculations on the image data stored in the buffer 7 memory 6A according to microcode instructions sent from the memory 8. It is equipped with the four 111j operation functions of addition, subtraction, multiplication, and division so that calculations can be executed.

A large number of microcode instructions from the microprogram memory 8 are also sent to the buffer memory 6A, and signals for controlling the sequence flow of this device are fed back from the microprogram memory 8 to the sequencer 9. It has become.

The microcode instruction group has a width of, for example, 32 to 64 bits, and each bit directly controls the arithmetic unit 10 and the buffer memory 6A. In order to allow the buffer memory 6A and the buffer memory 6A to operate in unison, a clock of several hundred nanoseconds is provided, and this clock is controlled by the CPU to allow the processing microprogram to flow.

Although not shown, the image processor 7A also includes a large number of emphasis coefficients β1. A β table including β2... and a large number of gradation coefficients γl, γ2. It has a built-in γ table including...

Next, the image processing step of the X-ray image data by the image processing device f3A having the above configuration is performed for each pixel data p (parameter Nl of the non-sharp mask) of the X-ray image data in FIG.
=9. The explanation will be given with reference to an explanatory diagram showing the processing microprogram stored in the microprogram memory 8 in FIG. 4.

In addition, the position 1!3s (i − (Nl −1
)/2. j −(Nl−1)/2) and the coordinates 5(i−<N−1)/2. in FIG. It is assumed that j-(N-1>/2) is the same.

The processing microprogram shown in FIG. 4 is different from the one shown in FIG. This is because a processed pixel data output command is provided.

This image processing device 3A basically processes Xa image data using the same image processing algorithm as the conventional device shown in FIG. That is, first, an initialization start command is sent from the CPU to the sequencer 9, and the sequencer 9 stores the instruction address in the microprogram memory 8.
send to

According to this instruction address, the microprogram memory 8 simultaneously sends the microcode instruction to the computing unit 10 and the buffer memory 6A. Coefficient βl.

β2, gradation coefficient γ=72, parameter Nl of non-sharp mask =9. N2-3) is set.

When this set is completed, the sequencer 9 & continues to hold the next command of the processing microprogram, a processing start command, at the same program count position on the processing microprogram.

During this time, the processing microprogram (is in a hold state).

Next, the CPU recognizes the quasi-fi1 state of the other n peripheral devices M(), and sends processing RQii:1 to the sequencer 9 when preparation is complete.

As a result, the processing microprogram shifts to a processing step for parameter N+ and starts arithmetic processing based on the above equation (1). This calculation process is first performed continuously in the pixel direction of the first row of the non-sharp mask. In this case, store the number of repeats in the sequencer 9 in advance (PUSH
), the processing microprogram continuously executes pixel processing for the set number of repeats, and stores the processed pixel data in the -H buffer memory 6A.

Next, the processing microprogram moves to the processing step for parameter N2 and is ready to execute the same pixel processing as in the case described above. By setting the coordinates of the unsharp mask, the processing step for parameter N2 is skipped in the first row of pixel processing, and the processing microprogram is line switched to the second row of pixel processing.

Here, the coordinates for performing the processing step for parameter N2 are S (i − (Nt 1)/2゜j −
S(i (NI
-G 1)/2. j −(Nr
+ 1 ＞/2) ~ 5(i-(Nr-
N2)/2. The following explanation will be given assuming that the value is set to j - (Nt - N2)/2).

In the same way, only the processing step for the parameter Nl is executed for the second and third lines of the unsharp mask of NI XN2, and these results are temporarily stored in the buffer. It is stored in the memory 6A.

At the pixel processing stage on the fourth line, the processing microprogram first executes the processing step for the parameter Nl (in this example, N1=9, so 9 pixel processing) is executed, and then the processing step for the parameter N2. Processing steps (3 pixel processing since N2=3 in this example) are executed.

At this time, the processing step for parameter N2 is executed because S(i~(N1+1 ＞/2.j−(N1+1
)/2)~S (i −(N+−N2 )/2.j−
(N1+1)/2) for the pixel data of each point.

Similarly, in the 5th and 6th lines, 91 is set for the parameter Nl.
The pixel processing of 1ii1 and the three rounds of pixel processing are executed for the parameter N2, and these processed pixel data are temporarily stored in a buffer. It is stored in the memory 6.

Further, the vixel processing on the 7th to 9th rows is the same as the vixel processing on the 1st to 3rd rows.

In this way, 81 processed pixel data for the parameter Nl and 9 processed pixel data for the parameter N2 are obtained from each pixel data of the unsharp mask, and these are temporarily stored in the buffer 7 memory 6A.

Next, the microprogram memory 9 sends a microcode to the arithmetic unit 10 according to the instruction address from the sequencer 9, and the arithmetic unit 10 then processes the processing pixel data for the parameter N+ by 3usA/l' 1=ΣS i,j / N 1'' to obtain the non-sharp mask signal '+J month 3us1, and then (S o -811st)
subtraction processing, multiplication processing β1(So −8ust),
Frequency emphasis processing of [30 β1 (So -8ust) ], S + -7t [SO + βt (So -8ust
) ] is performed sequentially, and the parameter N
An unsharp mask signal 3us2 corresponding to the coordinates is obtained for the processed pixel data for 2, and then (So-3us
2) subtraction processing, β2 (So -3032> multiplication processing, [5oi-β2 (So -3032)] frequency emphasis processing, 32-72 [80+β2 (So
-8LI32) ] gradation processing is performed.

In this way, in the image processing device 3A, the emphasis coefficient β
Two types of X-ray image data with different gradation coefficient γ and non-sharp mask parameter N are formed, and as a result, as shown in FIG. Two processed images 1'CIA and B having different tone processing and contrast can be formed.

The present invention is not limited to the embodiments described above, and various modifications can be made within the scope of the invention.

For example, the parameter N1 of the unsharp mask. N2 = N1
By setting N2, it is possible to avoid forming a processed image similar to that of the conventional apparatus.

[Effect of the Invention 1] According to the present invention described in detail below, a processed image obtained by performing processing using different sizes of non-sharp masks for the same two images on a single sheet of recording material is recorded in 21I! Therefore, it is possible to simultaneously view two images with different contrasts for the same image using one sheet of recording material, and it is possible to provide an image processing apparatus that can contribute to improving diagnostic performance.

Furthermore, since processing can be performed with different sizes of non-sharp masks at the same time, it is possible to improve the processing efficiency of radiation data and increase the throughput of the entire system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an enlarged block diagram showing details of the device shown in FIG. FIG. 4 is an explanatory diagram showing a microprogram stored in the apparatus shown in FIG. 1, FIG. 5 is an explanatory diagram showing a processed image on a recording material obtained by the apparatus shown in FIG. 1, and FIG.
A block diagram of the Shasei system, Figure 7 shows the conventional image 5t8i
A block diagram of the device, FIG. 8 is an explanatory diagram showing the coordinates of each pixel of X-ray image data, FIG. 9 is an explanatory diagram showing a microprogram not shown in FIG. 7 but stored in the device, and FIG. FIG. 8 is an explanatory diagram showing a processed image on a recording material obtained by the apparatus shown in FIG. 7; 3A... Image processing device, 6A... Buffer 7 memory, 7A... Image processor, 8...
Microprogram memory, 9...Sequencer. -11-~ Agent: Patent attorney Masayoshi Misawa. Ku゛A Funeral Figure 4 Figure 6 Figure 7

Claims (1)

[Claims] When forming a visible image on a recording material based on radiographic image data obtained by transmitting through a subject in a radiographic system, a non-sharp mask corresponding to each pixel data of the radiographic image data is provided. The signal Sus is obtained, and when the original image signal of the radiation image data is So, the emphasis coefficient is β, and the gradation coefficient is γ, perform the calculation expressed by the calculation formula S = γ [So + β (So - Sus)]. In an image processing apparatus capable of transmitting processed image data obtained by subjecting a recording material to frequency emphasis processing and gradation processing, the unsharp mask signal Sus
To obtain , two different mask sizes are set to obtain two unsharp mask signals Sus_1 and Sus_2, and these unsharp mask signals Sus_1 and Sus_2 are subjected to frequency emphasis processing and gradation processing, respectively. What is claimed is: 1. An image processing device comprising a calculation function capable of simultaneously sending out multiple pieces of processed image data to a recording material.