JPH01120620A - Non-linear window processor - Google Patents

Abstract

PURPOSE:To ensure the display with no diagnosing error by selecting the window function of a band including the desired data out of the input gradation value data at the processing carried out by plural window functions. CONSTITUTION:A nonlinear window processor contains as image memory 2 which stores the gradation value pictures received from a host computer via an interface I/F1, a gradation value band recognizing part 3 which receives data from the memory 2, a 1st window converting part 4, and a 2nd window converting part 5. Furthermore a window selecting part 6, a D/A converter 7, a video controller 8 and a display monitor (CRT) 9 are added to the processor. The part 3 checks whether the gradation value (CT value) data received from the memory 2 is accordant with 1st or 2nd window function. Then both parts 4 and 5 produce the linear window function values related to each window width WW and level WL sent from a console panel.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a nonlinear window processing device for performing window processing on image data of a plurality of gray value bands.

(Conventional technology) Linear windows for traditional windowing.

There are two types of nonlinear windows, and a linear window has a function as shown in FIG. Such a linear window is used to observe changes in gray value maintenance only in a single range, whereas a non-linear window is used to perform window processing over a plurality of bands.

A typical example of this nonlinear window is processing by multiplexing linear windows. This method is the 13th
As shown in the figure, regarding the function between the input CT value (m value) and the corresponding output, for example, the lung part is performed using the first window function W1, and the other riIi organs and bone parts are is processed by the second window function W2 and two bands are displayed.
In order to perform 1°W2 with one processing device, the signals were combined into one window function as shown in FIG. 14.

Next, the conventional method will be specifically explained with reference to FIGS. 15 and 16.

As shown in FIG. 15, collected data from a CT device, etc. is stored in an image memory 12 via an interface 11, and the data in this image memory 12 (for example, 12
Video lookup table (VLT) 1 in which a window function is set in advance when reading bit data)
3, desired data (for example, 8 bits) is read out, the output is converted into analog data by a D/A converter 15, and is displayed on a monitor 17 via a video controller 16. Here, the data written to the video lookup table 13 is created by the video lookup table creation device 14 using function data (corresponding output data using window level WL and window width WW as input values) as shown in FIG. It is now possible to write what is written.

(Problems to be Solved by the Invention) According to the prior art as described above, as shown in FIG.
If 2 is increased, an overlapping area (A> will occur between the first window W1 and the second window W2. In other words, although the area (A> should be processed in the second window, It will be processed in one window.

As a result, tissues that should originally be displayed with low brightness in the second window are displayed with high brightness in the first window, leading to diagnostic errors.

SUMMARY OF THE INVENTION An object of the present invention is to provide a nonlinear window processing device that can perform processing using a plurality of window functions so that no overlap occurs, and can display images without diagnostic errors.

[Configuration of the Invention (Means for Solving the Problems)] In order to achieve the above object, the present invention selects the window function of the band to which the gray value data belongs from the input gray value data, and The data is processed using individual window functions, and the outputs of each window processing section are combined and displayed as an image.

(Operation, Use) The operation of the above means will be explained with reference to FIGS. 3 and 4.

For example, if the input values A, B, and C in Figure 3 are to be processed by the first window function W1, and the input values are to be processed by the second window function W2, the converted data of each point will be A. It will be output as 'e B'*C',D'. However, the output values A', B'
, C' are shown in FIG. 4(a) because the mutual brightness changes are so large that it is difficult to see the image in that band.

As shown in (b), the window width WW1 of the first window function W1 is set as a function W1' that is expanded, and the second window function W2 is left unchanged.

At this time, the selection unit instructs to select the processing by the first window function for the bands of input values A, B, and C, and the processing by the second window function for the input values, and based on this, processing is performed so that no input value is processed by the first window function. On the other hand, if the width of the second window function is widened, the problem that the inputs A, B, and C are processed by the second window function does not occur.

(Example) The present invention will be specifically explained below using Examples.

FIG. 1 is a block diagram showing an embodiment of the nonlinear window processing device of the present invention.

Reference numeral 2 in the figure is an image memory that stores a grayscale value image (for example, a CT image frame) sent from the host computer (008) via an interface (I/F) 1, and the data stored in the image memory is stored in the grayscale value band recognition unit 3. .first window converter 4.sent to second window converter 5.

The gradation value band recognition unit 3 receives the gradation value (CT value) data sent from the image memory 2 from the first. This is to check which of the second window functions is suitable. 1st. Second
The window converters 4 and 5 generate linear window function values for each window width WW and window level WL given from the console panel, and write the conversion pattern to a video lookup table (VLT) provided in each converter. It has a function. 6 in the figure is a window selection section; One of the outputs of the second window is selected and output based on the output from the gray value recognition section 3, and sent to the D/A converter (DAC>7).

The display data converted into an analog signal by the DAC 7 is sent to a display monitor (CR) via a video controller 8.
It is output to T>9 and used for display.

In addition, 1st. Switches for setting the width WW and level WL of the second window are provided on the console panel.
You can select and set any value.

Here, the band setting value serving as the reference value in the gray value band 1fA recognition section 3 will be explained with reference to the format shown in FIG. As shown in the figure, when there are N window processing units, the upper limit of the first window processing unit is set to 900.
The upper limit of the second window processing section is 2000. Third, the host computer sets the value as a band setting value and gives it to the grayscale value band recognition unit 3. As a standard for determining such a band setting value, for example, in order to separate the lungs, organs, and bones, first set the window width WW = 1 with a normal linear window, and set the window level WL.
It can be set by changing the window level and finding a window level that separates the two.

Next, the operation of the device will be explained with reference to FIGS. 3 to 8. Note that the flow of data in each figure is indicated by a thick line.

As shown in FIG. 3, a first window function W1 with a window level WL1° and a window width WW1 and a first window function W1 with a window width WW1 and a level WL2. Values A and B that exist in each band based on two linear window functions, a second window function W2 with a width WW2.

If C belongs to a band for which processing by the first window is preferable (for example, lung field), and the value belongs to a band for which processing by the second window is preferable (for example, organs, bones), such a band Iti, Data regarding set values are determined as shown in FIG. 2 and are provided to the gray value band recognition section 3 from the host computer.

However, when window conversion processing is performed using the function shown in FIG. 3, the converted values A', B' of the values A, B, and C are
, C' is high and the displayed image is difficult to display, the operator will set a function W1' that widens the window width WW1 of the first window function, as shown in FIG. 4(a). As a result, the window width WW1 of the first window function and the window width WW of the second window function
An overlap occurs between 2 and 2.

However, due to the data flow shown in FIG. 5, the value is recognized by the grayscale value band recognition unit 3 as being for the first window processing, and the window selection unit 6 operates thereby to select the first window function (FIG. 4). (a)> processing is performed. Also, the value B.

Based on the data flow shown in FIGS. 6 and 7, C is also processed by the first window function (FIG. 4(a)) in the same manner as above, and A' in FIG. 4(a), B', C'
Output values such as are jq'd and provided for display.

Then, the value DG is determined by the gray value band recognition unit 3,
It is recognized that the data is suitable for the second window processing, and the window selection unit 6 operates accordingly, so that the data is processed according to the data flow shown in FIG.
After being converted to the output value D' in Figure (b), it is provided for display.

Even if the window width of any one of the plurality of window functions is changed, a window function suitable for each gray value is selected and processed.

The present invention is not limited to the embodiments described above, and various modifications are possible.

In the embodiment described above, most of the components can be configured as hardware or as a software configuration based on the blocks shown in FIG. 9. The structure and operation of such an embodiment device will be explained with reference to FIGS. 10 and 11.

Grayscale value image data sent from the host computer is sent to the image memory 22 via the interface section 21. For example, the image data in the image memory 22 is 12
This is 8-bit data, which is read out sequentially and converted to 8-bit data by a VLT (video lookup table) 23, and then sent to a D/A converter 25 and a video controller 26.
It is displayed on the CRT 27 via. The configuration up to this point is almost the same as the conventional device, but the VLT generation section 24 is different.

The VLT generating section 24 has a software configuration as shown in FIG. That is, the band setting value described in the above embodiment is input to the window function reading section 24B, and the write address is controlled by the data corresponding to O to 4095 from the VLT memory address generation section. 8-bit data for display is obtained by the window function of the band setting value that includes the VLT address, and
Written to LT23. At this time, the first window band and the second window band are determined based on the same concept as in the embodiment, and a signal based on the determination result is output, and the first window function section 24G or the second window function section 24D Select one of them and output it, and output that output to VL.
It is set to predict T23.

As a result, the window functions W1 and W2 shown in Fig. 11 (a>, (b)) are clipped and synthesized using the band setting values shown in Fig. 11 (C) and synthesized as shown in Fig. 11 (d). A composite function W as shown is obtained. Since this is written as a VLT pattern, the same effects as in the above embodiment can be achieved.

[Effects of the Invention] According to the present invention detailed above, when performing processing using a plurality of window functions, it is possible to perform processing so that no overlap occurs even if any one of the functions is changed. It is possible to provide a nonlinear window processing device that does not cause errors.

Therefore, for example, no matter how you change the density value of an organ, it will not have an adverse effect on the window displaying the lungs, and conversely, changing the window for the lungs will have an adverse effect on the organ display window. Never.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a format diagram of band setting values used therein, and Figs. 5 to 8 are data flow diagrams for explaining the operation of the present invention. FIG. 9 is a block diagram showing another embodiment of the present invention. Detailed block diagram of the VLT generation section included in Figure 9, Figure 11 (a)
). (b), (c), and (d) are diagrams showing a window function for explaining the operation of Figure 10, Figure 12 is a diagram showing a linear window function, and Figures 13 and 14 are problems caused by the conventional device. Diagram showing a window function for explaining points, No. 15
The figure is a block diagram of a conventional device, and FIG. 16 is a data format diagram of a video lookup table of the conventional device. 1...Interface, 2...Image memory,
3... Grayscale value band recognition section, 4... First window conversion section, 5... Second window conversion section, 6... Window selection section, 7... D/A converter, 8
...Video controller, 9...Monitor. Figure 3 Figure 4: (a) Figure 11 Figure 5P112

Claims (1)

[Claims] In a device that performs window processing of input data using a plurality of window functions, the relationship between each window function and the band of input data that matches it is set in advance,
The window function of the band to which the input data belongs is selected from the input data, and the data of each band is processed by the individual window function, and the output of each window processing section is combined and presented for display. A nonlinear window processing device.