JP2006000199A - Display method of test pattern, and medical image displaying apparatus and its program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the precision of visibility of an operator to execute a calibration more precisely by the visual observation of the operator. <P>SOLUTION: When a control section 11 makes a display section 13 display N-pieces test patterns, it generates the screen data in which one test pattern is disposed on one screen and outputs the same with the driving level information set in the test pattern to the display section 13 to switch and display the one pattern on the one screen respectively. Also, the control section generates the screen data in which the test pattern to be displayed on each the changeover screen is moved and disposed at the different display position at every time when the screen is switched, and changes the display position of the same on each the changeover screen. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a test pattern display method used when correcting display gradation characteristics of a medical image display device by visual observation by an observer, a medical image display device that displays a test pattern, and a program.

  In the medical field, monitor diagnosis in which a patient's medical image obtained by various examination imaging such as X-ray imaging, MRI (Magnetic Resonance Imaging) imaging, ultrasonic imaging, etc. is displayed on a monitor for interpretation is widespread. . In addition, with the development of networks inside and outside hospitals, it is possible to interpret the same image on monitors at different locations. However, if the monitor used for interpretation is of different types such as LCD (Liquid Crystal Display), CRT (Cathode Ray Tube), etc., the display characteristics will be different, so the appearance of the image will be different, and the same type of monitor. However, the appearance of the image may still differ depending on the degree of deterioration due to its use and the installation environment.

  In this way, if there are variations in the appearance of images on individual monitors, the diagnostic accuracy will be affected. Therefore, correction of display tone characteristics (hereinafter referred to as calibration) is performed to change the appearance of images on each monitor. It is necessary to unify. Conventionally, calibration is performed using a luminance meter. However, since the luminance meter is generally expensive, calibration using the luminance meter is expensive. In addition, when there are a number of monitors for image interpretation, the work of calibrating each monitor with a luminance meter one by one is very troublesome and complicated.

On the other hand, a method is also proposed in which an operator visually confirms a calibration result after performing calibration using a luminance meter (see, for example, Patent Document 1). In the calibration method described in Patent Document 1, as shown in FIG. 19, a plurality of test patterns displayed at different brightness levels are displayed on a monitor, and the brightness of each test pattern is displayed to an operator (observer). The level is confirmed visually.
JP-A-11-327501

  However, as shown in FIG. 19, when calibration is performed by displaying a plurality of test patterns on one screen, the test pattern adjacent to the judgment target test pattern and the adjacent test pattern are in the operator's field of view. As a result, it becomes difficult to perform accurate calibration.

  In addition, since test patterns having the same shape and size are always displayed at the same position, an afterimage of the test pattern to be previously determined may remain in the eyes of the operator. In this case, there is a possibility that the visual accuracy of the operator is lowered by affecting the test pattern to be determined that the previous test pattern is displayed later.

  An object of the present invention is to improve the accuracy of visual recognition by an operator and make it possible to perform calibration by visual observation of the operator more accurately.

The invention according to claim 1 is a test pattern display method,
A test pattern display method for displaying a plurality of test patterns for correcting display gradation characteristics of a medical image display device on a display unit of the medical image display device,
The plurality of test patterns are switched and displayed one screen at a time, and the display form of the test pattern displayed on each switching screen is changed.

The invention described in claim 2 is the test pattern display method according to claim 1,
The display mode of the test pattern is changed every time the screen is switched.

The invention described in claim 3 is the test pattern display method according to claim 1 or 2,
The display form of the test pattern is changed in each switching screen.

The invention according to claim 4 is the test pattern display method according to any one of claims 1 to 3,
The display form is a display position of a test pattern.

The invention according to claim 5 is the test pattern display method according to any one of claims 1 to 3,
The display form is a display size of a test pattern.

The invention according to claim 6 is the test pattern display method according to any one of claims 1 to 3,
The display form is a display shape of a test pattern.

The invention according to claim 7 is the test pattern display method according to any one of claims 1 to 6,
The brightness level of the background area of the test pattern displayed on each switching screen is made to correspond to the brightness level of the test pattern.

The invention according to claim 8 is a medical image display apparatus,
Display means for displaying medical images;
Control for switching a plurality of test patterns for correcting display gradation characteristics of a medical image display device one pattern at a time on the display means and changing the display form of the test pattern displayed on each switching screen Means,
It is characterized by providing.

The invention according to claim 9 is:
On the computer,
A function to display a medical image on a display means;
A function for switching a plurality of test patterns for correcting display gradation characteristics of a medical image display device one pattern at a time on the display means and changing the display form of the test pattern displayed on each switching screen When,
It is a program for realizing.

  According to the first, eighth, and ninth aspects of the present invention, when the test pattern is displayed, the display is switched and displayed one pattern at a time on the screen. By entering, it can prevent that a visual recognition precision falls. In addition, since the display form of the test pattern displayed on each switching screen is changed, it is possible to prevent an afterimage of the test pattern from remaining, or even when an afterimage of the test pattern remains, the afterimage becomes a test pattern to be visually recognized next. It is possible to prevent the influence. Therefore, more accurate calibration can be performed.

  According to the invention described in claim 2, since the display pattern of the test pattern is changed every time the screen is switched, the test pattern displayed on the previous screen affects the visual recognition of the test pattern displayed on the subsequent screen. Can be prevented.

  According to the third aspect of the present invention, since the display pattern of the test pattern is changed in each switching screen, an afterimage of the test pattern is generated by constantly changing the display pattern of the test pattern displayed in one screen. Can be prevented.

  According to the fourth aspect of the present invention, when the display position of the test pattern is changed each time the screen is switched, the test pattern to be visually recognized next is different even when an afterimage of the test pattern on the previous screen remains. Since it remains in the position, it is possible to prevent the afterimage of the test pattern on the previous screen from affecting the test pattern displayed on the subsequent screen. On the other hand, when the display position is changed in each switching screen, the display position of the test pattern is not fixed, and thus the occurrence of the afterimage can be prevented.

  According to the invention described in claim 5, by changing the display size of the test pattern every time the screen is switched or within each switching screen, the display form of the test pattern is not fixed and the occurrence of the afterimage is prevented. can do. Alternatively, even when an afterimage occurs, it is possible to reduce the influence on the test pattern displayed on the subsequent screen, and to prevent the operator's visual accuracy from being lowered.

  According to the sixth aspect of the invention, since the display shape of the test pattern is changed, the display form of the test pattern is not fixed by changing the display pattern every time the screen is switched or within each switching screen. Occurrence can be prevented. Alternatively, even when an afterimage is generated, the influence on the subsequent test pattern can be reduced, and a reduction in the visual accuracy of the operator can be prevented.

<First Embodiment>
In the first embodiment, an example will be described in which a plurality of test patterns are switched and displayed one screen at a time, and the display position of the test pattern on each switching screen is changed every time the screen is switched.

First, the configuration will be described.
FIG. 1 shows an internal configuration of the medical image display apparatus 10 in the first embodiment.
As illustrated in FIG. 1, the medical image display apparatus 10 includes a control unit 11, an operation unit 12, a display unit 13, a communication unit 14, a RAM (Random Access Memory) 15, and a storage unit 16.

  The control unit 11 develops various control programs such as a system program stored in the storage unit 16, the first pattern display processing program according to the present invention, and a calibration processing program in the RAM 15, and operates each unit according to the control program. Centralized control.

  In the first pattern display process, the level range of the drive level that can be displayed and driven by the medical image display apparatus 10 is divided into N equal parts, and each of the N test patterns in which the N equally divided drive levels are set is displayed. The information is output to the display unit 13 together with the drive level information, and each test pattern is displayed and driven at the set drive level. That is, each test pattern is displayed at a luminance level corresponding to each drive level divided into N equal parts. Each test pattern is formed from two display areas in which different drive levels are set so as to be displayed at different luminance levels.

  When displaying the N test patterns on the display unit 13, the control unit 11 generates screen data in which one test pattern is arranged on one screen, and the display unit 13 together with information on the drive level set in the test pattern. To display one pattern at a time on the screen. In addition, the test pattern displayed on each switching screen is moved every time the screen is switched to generate screen data arranged at different display positions, and the display position is changed over each switching screen. That is, the control means can be realized by the cooperation of the control unit 11 and the first pattern processing program.

  In the calibration process, when a brightness level adjustment operation is performed on the displayed test pattern via the operation unit 12, the drive level in the test pattern is changed according to the operation instruction, and the display unit 13 performs display driving. Let When the adjustment operation is completed, a correction curve for correcting the display gradation characteristics of the medical image display device 10 is calculated based on the drive level values of the two display areas forming each test pattern. Then, an LUT (Look Up Table) that defines an output value for the input value of the correction curve is created and stored in the storage unit 16.

  The display characteristic refers to the correlation between the drive level and the luminance level, and the display gradation characteristic refers to the correlation between the input level of the pixel value in the image data to be displayed and the luminance level when the image data is displayed and output. Say.

  The operation unit 12 includes a keyboard and a mouse. When these keyboard and mouse are operated, an operation signal corresponding to the operation is generated and output to the control unit 11. The operation unit 12 may have a touch panel formed integrally with the display unit 13.

  The display unit 13 is a display unit having a monitor such as an LCD or a CRT, and drives the monitor according to control by the control unit 11 to display various screen data such as an operation screen and a test pattern display screen. When each test pattern [n] is displayed, the monitor is displayed and driven at a drive level designated according to the drive level information input together.

  The communication unit 14 has communication interfaces such as a NIC (Network Interface Card), a modem, and a router, and performs data communication with external devices on a LAN (Local Area Network) provided in the hospital via these communication interfaces. I do. For example, a medical image data is acquired by accessing an image server in which medical images of patients are managed in a database.

  The RAM 15 forms a work area for temporarily storing various programs executed by the control unit 11 and data processed by these programs.

  The storage unit 16 is configured by a magnetic or optical recording medium, a semiconductor memory, or the like, and stores various control programs such as a system program and a calibration processing program. Further, as parameters used during the calibration process, parameters for the amount of movement when the display position of the test pattern is moved over each switching screen, parameters for the movable area range, display screen size of the display unit 13, and the like As a processing result of the program, for example, an LUT for correcting display gradation characteristics of the medical image display device 10 created by calibration processing is stored.

The storage unit 16 stores a plurality of test pattern data used in the calibration process.
FIG. 2 shows an example test pattern.
As shown in FIG. 2, the test pattern [n] (n in parentheses indicates a pattern number assigned to identify each test pattern. N = 1,..., N) is driven on the display unit 13. The level range of possible drive levels, that is, 0 to the maximum drive level DDL _max is divided into N equal parts, and the drive level is created corresponding to each of the N drive levels. In the present embodiment, an example of dividing into eight parts is shown, but it is assumed that the number of N to be equally divided can be appropriately set depending on the accuracy of calibration. When it is desired to perform calibration with high accuracy, it is preferable to increase the N number.

In each test pattern [n], two display areas having different drive levels are formed as shown in FIG. One display area is set with a drive level in which the maximum drive level DDL _max is equally divided into N, and the other display area is set with a drive level that is a certain level higher than the drive level set in one of the display areas. Yes. The display area in which the drive level divided into N is set is referred to as a reference target, and the display area in which the drive level is set to be higher than the reference target is referred to as an adjustment target.

When the drive level of the reference target is DDLK [n] and the drive level of the adjustment target is DDLT [n], DDLK [n] is represented by the following equation 1, and DDLT [n] is represented by the following equation 2.

Note that the test pattern [n] is not limited to the test pattern [n] including the rectangular display area as illustrated in FIGS. 2 and 3, but is the test pattern [n] including the line display area as illustrated in FIGS. 4 and 5. ]. In this case as well, the maximum drive level DDL _max is equally divided into N, and N test patterns [n] in which the respective N drive levels are set are created.

Each test pattern [n] shown in FIG. 4 is formed with a plurality of pairs of lines, with two line-shaped display areas having different driving levels set as a pair of lines as shown in FIG. Yes. A drive level in which the maximum drive level DDL _max is equally divided into N is set in one line of the line pair, and a drive level higher than the drive level set in the one line is set in the other line. Yes. The line in which the driving level divided into N is set is the reference target, and the line in which the driving level is set to be higher than the reference target is the adjustment target.
In the following description, in order to distinguish the types of test patterns [n], the test patterns shown in FIGS. 2 and 3 may be referred to as square patterns, and the test patterns shown in FIGS. 4 and 5 may be referred to as line patterns.

Next, the first pattern display processing and calibration processing executed by the medical image display apparatus 10 of the present embodiment using the test pattern [n] will be described.
FIG. 6 is a flowchart for explaining the first pattern display process, and FIG. 7 is a diagram showing the transition of the display screen displayed during the process. This process is started when calibration is selected from the environment setting menu.

  In the first pattern display process shown in FIG. 6, first, the pattern number n of the test pattern to be displayed is set to an initial value n = 1 (step S11). When the pattern number n is set, the control unit 11 reads the data of the test pattern [n] of the pattern number n from the storage unit 16. The test pattern [n] is arranged at a predetermined initial position on the display screen, and the drive level of the background area of the test pattern [n] is the same as the reference target of the test pattern [n]. display screen data set to [n] is generated. The generated display screen data is output to the display unit 13 together with the drive level information of each display area. The display unit 13 drives the monitor according to the drive level information, and displays a display screen including the test pattern [n]. (Step S12).

  FIG. 7 is a display screen example of test patterns [1], [3], and [5]. Taking test pattern [3] as an example, only one pattern is displayed on one screen, and the background area is displayed and driven at the same drive level as the reference target, so that it is displayed at the same luminance level as the display area of the reference target. The The test pattern [3] is arranged and displayed at a position set in advance as an initial position. Note that the dotted line in the figure indicates an area range r set in advance as an area where the test pattern [n] can be moved, and the dotted line is not actually displayed on the display screen.

  When the test pattern [n] is displayed in this way, the operator can make the minimum luminance level difference between the adjustment target and the reference target in the test pattern [n] visually visible via the operation unit 12. Until the brightness level of the adjustment target is increased or decreased. The minimum visually recognizable luminance level difference is a luminance level difference at the limit where the luminance level difference can be visually recognized as a result of the operator adjusting the luminance level of the adjustment target in accordance with the luminance level of the reference target. Specifically, when the luminance level of the adjustment target is lowered by one more level, the luminance level is adjusted until the operator cannot distinguish the luminance level difference between the adjustment target and the reference target.

  In the medical image display device 10, when an operation for adjusting the luminance of the adjustment target is performed via the operation unit 12, the operation signal is analyzed, and it is determined whether an operation instruction has been given to increase or decrease the luminance level. (Step S13). When an operation instruction is given to increase the luminance level (step S13; up), the adjustment target drive level DDLT [n] is increased by one level, and the adjustment target being displayed is increased to the drive level DDLT [n]. The display is driven (step S14). On the other hand, when an operation instruction is given to reduce the brightness (step S13; down), the drive level DDLT [n] of the adjustment target is lowered by one level, and the drive level DDLT [n] in which the adjustment target being displayed is lowered. The display is driven (step S15). That is, the luminance level is raised and lowered by one drive level according to one operation. Even if the operation to lower the luminance level of the adjustment target is repeated, the adjustment operation that is lower than the drive level of the reference target is disabled so that the luminance level of the adjustment target does not become lower than the luminance level of the reference target. The adjustment operation is limited.

When the drive level adjustment operation is performed, it is determined whether or not the adjustment operation has been completed (step S16). If the adjustment operation is still being performed via the operation unit 12 (step S16; N), step Returning to the process of S13, the luminance level is adjusted in accordance with the input operation instruction. On the other hand, when the adjustment operation is completed (step S16; Y), the drive level DDLT ′ [n] of the adjustment target of the test pattern [n] at the end of the adjustment is determined, and the drive level DDLT ′ [n] and the reference target are determined. A difference ΔDDL _jnd [n] from the drive level DDLK [n] is calculated (step S17). This ΔDDL _jnd [n] corresponds to the minimum luminance level difference visible to the operator in the test pattern [n].

  Next, it is determined whether or not the adjustment operation described above has been completed for all test patterns [n] (step S18). If the adjustment operation has not been completed for all test patterns (step S18; N), the pattern number n is incremented by 1 (step S19). Then, the data of the test pattern [n] with the incremented pattern number n is read from the storage unit 16, and the test pattern [n] is moved by a predetermined amount from the display position of the currently displayed test pattern [n]. Display screen data in which the driving level of the background area of the test pattern [n] is set to the same driving level DDLK [n] as the reference target of the test pattern [n] is generated. Note that the display position of the test pattern [n] moves within a predetermined area range r.

  The generated display screen data is output to the display unit 13 together with the drive level information of each display region. The display unit 13 performs display drive of the monitor according to the drive level information, and the display screen data including the test pattern [n] is displayed. It is displayed (step S20). When the test pattern [n] of the next pattern number n is thus displayed, the process returns to step S13, and the adjustment operation is repeated for the test pattern [n].

  That is, as shown in FIG. 7, only one test pattern [n] is displayed on one screen on the display unit 13, and each test pattern [n] is sequentially switched and displayed in the order of the pattern numbers. Further, each time the screen is switched, the display position of the test pattern [n] is moved by a predetermined amount, and the display position is changed over each switching screen.

When all the test patterns [n] are displayed and the adjustment operation is completed (step S18; Y), the process proceeds to the LUT creation process shown in FIG.
In the LUT creation processing shown in FIG. 8, ΔDDL _jnd [n] calculated with respect to the drive level DDLK [n] of the reference target of each test pattern [n] is plotted as shown in FIG. An approximate function g (DDL) is calculated (step S101). That is, each ΔDDL _jnd [n], which is a discrete value, is interpolated to obtain a continuous value corresponding to the drive level DDL in the entire level range. That is, the approximate function g (DDL) is a function indicating the correspondence between the drive level DDL and the minimum drive level difference ΔDDL _jnd [n].

Next, a function h (DDL) obtained by integrating the calculated function g (DDL) for each drive level DDL is calculated by the following expression 3 (step S102). The g (DDL) indicates the slope of h (DDL).

FIG. 10 is a diagram illustrating h (DDL). The X axis represents the drive level DDL, and the Y axis represents h (DDL) with respect to the drive level DDL. At this time, if the value of h (DDL) corresponding to the maximum drive level DDL _max that can be driven by the medical image display apparatus 10 is I _max , h (DDL) so that this I _max corresponds to the maximum drive level DDL _max. (That is, the value of the Y axis) is normalized, and f (DDL) indicating the normalized h (DDL) is calculated by the following expression 4 (step S103).

Then, the drive level DDL that is the unit of the X axis in FIG. 10 is replaced with the input level of the image value (P _max in the figure indicates the maximum gradation that can be expressed by the medical image display device 10), and the unit of the Y axis. A curve as shown in FIG. 11 is created by replacing a certain h (DDL) with the calculated f (DDL). With this curve, it is possible to obtain a drive level that realizes a corresponding luminance level from the input level of the pixel value so that the input level of the pixel value is finally displayed at a luminance level visually linear to the input level. it can. That is, it is a correction curve for correcting display gradation characteristics (that is, the relationship between the input level of the pixel value and the luminance level when actually displayed according to the input level) according to the display characteristics of the medical image display device 10. . In the control unit 31, an output value corresponding to the input value of the correction curve is calculated and tabulated, and an LUT is created (step S104). When the created LUT is stored in the storage unit 16 as an LUT for correcting the display gradation characteristics of the medical image display device 10, this processing is terminated.

  When displaying a medical image, the created LUT is referred to, a drive level (output value) corresponding to the input level (input value) of the pixel value of the medical image is obtained, and display drive is performed at the drive level. . Since the drive level obtained by the LUT is a drive level that is corrected so that the luminance level when the drive display is performed at the drive level has a linear relationship with the input level of the pixel value, the medical image display The display gradation characteristics of the medical image display apparatus 10 are corrected according to the display characteristics of the apparatus 10 and the visual characteristics of the operator.

  As described above, according to the first embodiment, when a calibration test pattern is displayed, the pattern is switched and displayed one pattern at a time. Therefore, it is possible to prevent the visual recognition accuracy from being lowered by entering a test pattern other than the test pattern to be visually recognized in the visual field of the operator. Therefore, more accurate calibration can be performed.

  In addition, since the display position of the test pattern [n] is moved each time the screen is switched, even if an afterimage of the test pattern [n] displayed on the previous screen is generated, the test pattern [n] n] is displayed at a position different from the display position of the test pattern [n] on the previous screen, so that an afterimage of the test pattern [n] on the previous screen is prevented from affecting the test pattern [n] being visually recognized by the operator. can do.

  Further, on each switching screen, the background area of the test pattern [n] is displayed at the same luminance level because it has the same drive level DDLK [n] as the reference target of the test pattern [n]. In this way, by associating the luminance level of the test pattern [n] with the luminance level of the background area, the eyes of the operator adapt to the luminance level and the visual accuracy is improved. In this embodiment, the driving level of the background area is set to the same driving level DDLK [n] as that of the reference target. However, the luminance level of the background area also changes in accordance with the luminance level of the test pattern [n]. If there is, for example, the driving level of the background area is set to an average value of DDLK [n] and DDLT [n], or other values are set such as setting within the range of DDLK [n] to DDLT [n]. Also good.

  In this embodiment, an example using a square pattern has been described, but the same processing is performed when a line pattern is used. FIG. 12 shows a screen transition diagram when a line pattern is used. As in the case of the rectangular pattern, one pattern is switched and displayed on one screen, and the display position of the line pattern is moved each time the screen is switched.

Second Embodiment
In the second embodiment, an example will be described in which a plurality of test patterns are switched and displayed one pattern at a time, and the display position of the test pattern is changed in each switching screen.

First, the configuration will be described.
Since the medical image display apparatus in the second embodiment has substantially the same configuration as the medical image display apparatus 10 in the first embodiment, the illustration thereof is omitted, and the same components are denoted by the same reference numerals and different functional parts are illustrated. Only explained. That is, the medical image display apparatus 10 in the second embodiment includes a control unit 11, an operation unit 12, a display unit 13, a communication unit 14, a RAM 15, and a storage unit 16.

The control unit 11 reads out the second pattern display processing program according to the present invention from the storage unit 16, and centrally controls the processing operation of each unit according to this program.
In the second pattern display processing, when N test patterns [n] are displayed on the display unit 13, the control unit 11 displays screen data in which one test pattern [n] is arranged on one screen as its test pattern [n]. ] Are output to the display unit 13 together with the information of the drive level set to [1], so that one pattern is switched and displayed on one screen. In addition, the display position is changed by moving the display position of the test pattern [n] displayed on each switching screen at a predetermined speed. That is, the control means can be realized by the cooperation of the control unit 31 and the second pattern processing program.

  The storage unit 16 stores a second pattern display processing program. Further, as parameters at the time of processing, information on the speed (in this embodiment, 0.5 cm / s) when moving the display position of the test pattern [n] on each switching screen, information on the movable area range Etc. are remembered.

Next, the operation of the medical image display device 10 in the second embodiment will be described.
FIG. 13 is a flowchart for explaining a second pattern display process executed by the medical image display apparatus 10, and FIG. 14 is a diagram showing screen transition of the display screen at the time of the process.

  In the second pattern display process shown in FIG. 13, first, the pattern number n of the test pattern to be displayed is set to an initial value n = 1 (step S31). When the pattern number n is set, the data of the test pattern [n] of the pattern number n is read from the storage unit 16. The test pattern [n] is arranged at a predetermined initial position on the display screen, and the drive level of the background area of the test pattern [n] is the same as the reference target of the test pattern [n]. display screen data set to [n] is generated. The generated display screen data is output to the display unit 13 together with the drive level information of each display area. The display unit 13 performs display drive of the monitor according to the drive level information, and displays the display screen of the test pattern [n]. (Step S32).

  FIG. 14 is a diagram illustrating display screen examples of test patterns [1], [3], and [5]. The test pattern [3] will be described as an example. The test pattern [3] is arranged and displayed at a predetermined position as an initial position on the display screen. Since the background area of the test pattern [n] is displayed and driven at the same drive level DDLK [n] as the reference target, it is displayed at the same luminance level as the reference target. The dotted line in the figure indicates a region range r that is predetermined as a region where the test pattern [n] can move, and is not actually displayed on the display screen.

  When the test pattern [n] is displayed, the movement of the display position of the test pattern [n] is started from the displayed initial position at a speed of 0.5 cm / s (step S33). Note that the test pattern [n] is moved within the region r.

  When the test pattern [n] is displayed in this way, the operator can make the minimum luminance level difference between the adjustment target and the reference target in the test pattern [n] visually visible via the operation unit 12. Until the brightness level of the adjustment target is increased or decreased. During this adjustment operation, the test pattern [n] on the display screen moves at a constant speed.

  In the medical image display device 10, when an operation for adjusting the luminance of the adjustment target is performed via the operation unit 12, the operation signal is analyzed, and it is determined whether an operation instruction has been given to increase or decrease the luminance level. (Step S34). When the operation instruction is given to increase the brightness level (step S34; up), the adjustment target drive level DDLT [n] is increased by one level, and the adjustment target being displayed is increased to the drive level DDLT [n]. The display is driven (step S35). On the other hand, when an operation instruction is issued to decrease the brightness (step S34; down), the drive level DDLT [n] of the adjustment target is lowered by one level, and the drive level DDLT [n] in which the adjustment target being displayed is lowered. The display is driven (step S36). Since the adjustment operation is the same as that in the first pattern processing in the first embodiment, the details are omitted here.

When the drive level adjustment operation is performed, it is determined whether or not the adjustment operation is completed (step S37). If the adjustment operation is still being performed via the operation unit 12 (step S37; N), step Returning to the process of S34, the luminance level is adjusted in accordance with the input operation instruction. On the other hand, when the adjustment operation is completed (step S37; Y), the drive level DDLT ′ [n] of the adjustment target of the test pattern [n] at the end of the adjustment is determined, and the drive level DDLT ′ [n] and the reference target are determined. A difference ΔDDL _jnd [n] from the drive level DDLK [n] is calculated (step S38).

  Next, it is determined whether or not the adjustment operation described above has been completed for all test patterns [n] (step S39). If the adjustment operation has not been completed for all the test patterns (step S39; N), the pattern number n is incremented by 1 (step S40). Then, the process returns to step S32, and the adjustment operation is repeated for the next test pattern [n]. That is, as shown in FIG. 14, only one test pattern [n] is displayed on one screen, and each test pattern [n] is sequentially switched and displayed in the order of the pattern numbers.

  When all the test patterns [n] are displayed and the adjustment operation is completed (step S39; Y), the process proceeds to the LUT creation process illustrated in FIG. The LUT creation process is the same as that in the first embodiment, and a description thereof will be omitted.

  As described above, according to the second embodiment, when the test pattern for calibration is displayed, the pattern is switched and displayed one pattern at a time. Therefore, it is possible to prevent the visual recognition accuracy from being lowered by entering a test pattern other than the test pattern to be visually recognized in the visual field of the operator. Therefore, more accurate calibration can be performed.

  Further, since the display position of the test pattern [n] displayed on each switching screen is moved on the screen and the display position always changes, the test pattern [n] displayed on each switching screen becomes an afterimage. It is possible to prevent the operator from remaining in the eyes. Therefore, it is possible to reduce the influence of the test pattern [n] on the previous screen on the test pattern [n] displayed on the subsequent screen, and to prevent the visual accuracy of the operator from being lowered.

  Further, on each switching screen, the background area of the test pattern [n] is displayed at the same luminance level because it has the same drive level DDLK [n] as the reference target of the test pattern [n]. In this way, by associating the luminance level of the test pattern [n] with the luminance level of the background area, the eyes of the operator adapt to the luminance level and the visual accuracy is improved. In this embodiment, the driving level of the background area is set to the same driving level DDLK [n] as that of the reference target. However, the luminance level of the background area also changes in accordance with the luminance level of the test pattern [n]. If there is, for example, the driving level of the background area is set to an average value of DDLK [n] and DDLT [n], or other values are set such as setting within the range of DDLK [n] to DDLT [n]. Also good.

  In this embodiment, an example using a square pattern has been described, but the same processing is performed when a line pattern is used. FIG. 15 shows a screen transition diagram when a line pattern is used. As in the case of the rectangular pattern, one pattern is switched and displayed on one screen, and the display position of the line pattern is moved each time the screen is switched.

<Third Embodiment>
In the third embodiment, an example will be described in which a plurality of test patterns are switched and displayed one screen at a time, and the display size of the test pattern on each switching screen is changed within the screen.

First, the configuration will be described.
Since the medical image display apparatus of the third embodiment has substantially the same configuration as the medical image display apparatus 10 of the first embodiment, the illustration thereof is omitted, and the same components are denoted by the same reference numerals and different functional parts are illustrated. Only explained. That is, the medical image display apparatus 10 according to the third embodiment includes a control unit 11, an operation unit 12, a display unit 13, a communication unit 14, a RAM 15, and a storage unit 16.

The control unit 11 reads out the third pattern display processing program from the storage unit 16, and controls the processing operation of each unit in accordance with this program.
In the third pattern display processing, when N test patterns [n] are displayed on the display unit 13, the control unit 11 displays screen data in which one test pattern [n] is arranged on one screen as its test pattern [n]. ] Are output to the display unit 13 together with the information of the drive level set to [1], so that one pattern is switched and displayed on one screen. In addition, in each switching screen, the display size of the test pattern [n] displayed on the screen is changed by enlarging or reducing at a constant speed. That is, the control means can be realized by the cooperation of the control unit 11 and the third pattern processing program.

The storage unit 16 stores a third pattern display processing program. In addition, parameter information necessary for the third pattern display processing, for example, a parameter for changing the display size of the test pattern [n] (in this embodiment, 1 cm ² / s), the display size, It stores parameters such as the maximum size that can be enlarged and the minimum size that can be reduced.

Next, the operation of the medical image display apparatus 10 according to the third embodiment will be described.
FIG. 16 is a flowchart for explaining a third pattern display process executed by the medical image display apparatus 10, and FIG. 17 is a diagram showing an example of a display screen displayed during the process.

  In the third pattern display process shown in FIG. 16, first, the pattern number n of the test pattern to be displayed is set to an initial value n = 1 (step S61). When the pattern number n is set, the data of the test pattern [n] of the pattern number n is read from the storage unit 16. Then, the test pattern [n] is arranged at a predetermined initial position on the display screen, and the drive level of the background area of the test pattern [n] is the same drive level as the reference target of the test pattern [n] DDLK [n Display screen data set to] is generated. The generated display screen data is output to the display unit 13 together with the drive level information of each display region. The display unit 13 performs display drive of the monitor according to the drive level information, and the display screen data including the test pattern [n] is displayed. It is displayed (step S62).

When the test pattern [n] is displayed, a change in the display size of the test pattern [n] is started at a speed of 1 cm ² / s from the displayed initial position, and enlargement or reduction is repeated (step S63).

FIG. 17 is a diagram illustrating a change in the display screen of the test pattern [3].
As shown in FIG. 17, the test pattern [3] is displayed at a predetermined position (center of the screen) as an initial position in the entire display screen. Since the background area of the test pattern [3] is displayed and driven at the same drive level DDLK [3] as that of the reference target, it is displayed at the same luminance level as that of the reference target.
The test pattern [3] is gradually enlarged every time, and when the maximum size is reached, the size is gradually reduced from the maximum size. When the size reaches a preset size as the minimum size, the size is enlarged again. That is, when the display screens d31, d32, and d33 are displayed in the order of d31 → d32 → d33, they are displayed in the order of d33 → d32 → d31, until the luminance adjustment for the test pattern [n] is completed. During this period, the display size is repeatedly enlarged or reduced.

  When the test pattern [n] is displayed as described above, the operator can, via the operation unit 12, the minimum luminance level at which the luminance level difference between the adjustment target and the reference target in the test pattern [n] can be visually recognized. An adjustment operation is performed to increase or decrease the luminance level of the adjustment target until the difference is reached. During this adjustment operation, the size of the test pattern [n] on the display screen changes at a constant speed.

  In the medical image display device 10, when an operation for adjusting the luminance of the adjustment target is performed via the operation unit 12, the operation signal is analyzed, and it is determined whether an operation instruction has been given to increase or decrease the luminance level. (Step S64). When an operation instruction is given to increase the luminance level (step S64; up), the drive level DDLT [n] of the adjustment target is increased by one level, and the adjustment level being displayed is increased by the drive level DDLT [n]. The display is driven (step S65). On the other hand, when an operation instruction is given to reduce the brightness (step S64; down), the drive level DDLT [n] of the adjustment target is lowered by one level, and the drive level DDLT [n] in which the adjustment target being displayed is lowered. The display is driven (step S66). The adjustment operation is the same as in the case of the first pattern display process in the first embodiment, and thus detailed description thereof is omitted here.

When the drive level adjustment operation is performed, it is determined whether or not the adjustment operation is completed (step S67). If the adjustment operation is still performed through the operation unit 12 (step S67; N), step Returning to the process of S64, the luminance level is adjusted in accordance with the input operation instruction. On the other hand, when the adjustment operation is completed (step S67; Y), the drive level DDLT ′ [n] of the adjustment target of the test pattern [n] at the end of the adjustment is determined, and the drive level DDLT ′ [n] and the reference target are determined. A difference ΔDDL _jnd [n] from the drive level DDLK [n] is calculated (step S68).

  Next, it is determined whether or not the adjustment operation described above has been completed for all test patterns [n] (step S69). When the adjustment operation has not been completed for all the test patterns (step S69; N), the pattern number n is incremented by 1 (step S70), and the process returns to step S62 to adjust the next test pattern [n]. Is repeated. That is, only one test pattern [n] is displayed on one screen, and each test pattern [n] is sequentially switched and displayed in the order of the pattern numbers.

  When all the test patterns [n] are displayed and the adjustment operation is completed (step S69; Y), the process proceeds to the LUT creation process illustrated in FIG. The LUT creation process is the same as that in the first embodiment, and a description thereof will be omitted.

  As described above, according to the third embodiment, when displaying the test pattern for calibration, the pattern is switched and displayed on the screen one by one. Therefore, it is possible to prevent the visual recognition accuracy from being lowered by entering a test pattern other than the test pattern to be visually recognized in the visual field of the operator. Therefore, more accurate calibration can be performed.

  In addition, since the display size of the test pattern [n] displayed on each switching screen is enlarged or reduced within the screen and the display size always changes, the test pattern [n] displayed on each switching screen is an afterimage. Thus, it can be prevented from remaining in the eyes of the operator. Accordingly, it is possible to reduce the influence of the test pattern [n] on the previous screen on the test pattern [n] displayed on the subsequent screen, and to prevent the visual accuracy of the operator from being lowered.

  In this embodiment, the display size of the test pattern [n] is changed in each switching screen. However, although the display size is fixed in each screen, the display size is changed every time the screen is switched. It is good.

  Further, on each switching screen, the background area of the test pattern [n] is displayed at the same luminance level because it has the same drive level DDLK [n] as the reference target of the test pattern [n]. In this way, by associating the luminance level of the test pattern [n] with the luminance level of the background area, the eyes of the operator adapt to the luminance level and the visual accuracy is improved. In this embodiment, the driving level of the background area is set to the same driving level DDLK [n] as that of the reference target. However, the luminance level of the background area also changes in accordance with the luminance level of the test pattern [n]. If there is, for example, the driving level of the background area is set to an average value of DDLK [n] and DDLT [n], or other values are set such as setting within the range of DDLK [n] to DDLT [n]. Also good.

  In the present embodiment, an example using a square pattern has been described, but the same processing is performed when a line pattern is used. That is, as in the case of the square pattern, one pattern is switched and displayed on one screen, and the line pattern is repeatedly enlarged or reduced on each switching screen to change the size.

  In the above description, the test pattern [n] is displayed at a predetermined ratio with respect to the display screen and its size is changed. However, as shown in FIG. 18, the square pattern is displayed on the entire screen. The size and shape of the adjustment target may be changed. In the example shown in FIG. 18, the display area of the adjustment target is changed from a square to a polygon, and further changed from a polygon to a circle. Also, the size is reduced and displayed as the shape changes. Thus, by changing the shape, it is possible to prevent the afterimage from occurring.

  Moreover, it is good also as displaying test pattern [n] combining 1st-3rd embodiment. For example, combining the first and third embodiments, the display position of the test pattern [n] is moved each time the screen is switched, and the display size of the test pattern [n] is constantly changed in each switching screen. It is good as well.

It is a figure which shows the internal structure of the medical image display apparatus 10 in this Embodiment. It is a figure which shows the test pattern [n] displayed at the time of a pattern display process. It is a figure explaining two display areas which form test pattern [n]. It is a figure which shows the test pattern [n] example formed of a line pair. It is a figure explaining the line pair which forms test pattern [n]. 4 is a flowchart for explaining a first pattern display process executed by the medical image display apparatus 10. It is a figure which shows the example of a display screen of test pattern [n] in 1st Embodiment. 4 is a flowchart for explaining LUT creation processing executed by the medical image display apparatus 10. It is a figure which shows the function g (DDL). It is a figure which shows the function h (DDL). 4 is a diagram illustrating a correction curve for correcting display gradation characteristics of the medical image display apparatus 10; FIG. It is a figure which shows the example of a display of the test pattern [n] which consists of a line pair. It is a flowchart explaining the 2nd pattern display process in 2nd Embodiment. It is a figure which shows the example of a display screen of test pattern [n] in 2nd Embodiment. It is a figure which shows the example of a display screen of test pattern [n] in the case of a line pattern. It is a flowchart explaining the 3rd pattern display process in 3rd Embodiment. It is a figure which shows the example of a display of test pattern [n] in 3rd Embodiment. It is a figure which shows the example of a display screen which changed the shape of test pattern [n]. It is a figure which shows the example of the conventional test pattern.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Medical image display apparatus 11 Control part 12 Operation part 13 Display part 14 Communication part 15 RAM
16 Memory unit

Claims (9)

A test pattern display method for displaying a plurality of test patterns for correcting display gradation characteristics of a medical image display device on a display unit of the medical image display device,
A method for displaying a test pattern, wherein the plurality of test patterns are switched and displayed on a screen one pattern at a time, and a display form of the test pattern displayed on each switching screen is changed.   The test pattern display method according to claim 1, wherein the display form of the test pattern is changed every time the screen is switched.   The test pattern display method according to claim 1, wherein the display form of the test pattern is changed in each switching screen.   The test pattern display method according to claim 1, wherein the display form is a test pattern display position.   The test pattern display method according to claim 1, wherein the display form is a test pattern display size.   The test pattern display method according to claim 1, wherein the display form is a test pattern display shape.   The test pattern display method according to claim 1, wherein the brightness level of the background area of the test pattern displayed on each switching screen corresponds to the brightness level of the test pattern. Display means for displaying medical images;
Control for switching a plurality of test patterns for correcting display gradation characteristics of a medical image display device one pattern at a time on the display means and changing the display form of the test pattern displayed on each switching screen Means,
A medical image display device comprising: On the computer,
A function to display a medical image on a display means;
A function for switching a plurality of test patterns for correcting display gradation characteristics of a medical image display device one pattern at a time on the display means and changing the display form of the test pattern displayed on each switching screen When,
Program to realize.