JP2021175111A - Image processing device, image processing method, and control program - Google Patents

Abstract

To set image data to be displayed to a desired gradation characteristic in correspondence with the actual gradation characteristic of a display device.SOLUTION: An image correction module (20) includes a gamma changing unit (240) that changes the gradation characteristic of image data to a desired gradation characteristic by using the maximum brightness and the minimum brightness of a display device, a display device correction unit (230) that derives a difference between the changed gradation characteristic after changing the gradation characteristic and the theoretical value of the desired gradation characteristic, and reflects the derived difference in the gradation characteristic of the input image data, and a display device gamma conversion unit (220) that performs gamma conversion on the gradation characteristic that reflects the difference according to the gradation characteristics of the display device (40), and outputs the gradation characteristic.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image processing device, an image processing method, and a control program for processing image data to be displayed on an image display device.

In recent years, the digitization of medical images such as radiographic images obtained by photographing patients at medical institutions has been progressing. Then, the digitized image data is displayed on a display device such as a CRT (Cathode-Ray Tube) or an LCD (Liquid Crystal Display). In addition, image data has also been displayed on a plurality of display devices connected via a communication network.

However, when a medical image is displayed on a plurality of display devices, the gradation characteristics of each display device are different, so that the gradation of the displayed image may be different even for the same medical image. It is not preferable for diagnosing a patient that the gradation displayed on the medical image differs depending on the display device. When displaying the same image of the same patient, it is desirable that the same image is displayed with the same gradation regardless of the display device.

Therefore, display devices for medical images ^{are classified into three management grades according to the maximum brightness (cd / m 2} ), brightness ratio, and contrast response, and the international standard DICOM (Digital Imaging and Communications in Medicine). Defines the format of medical images and the communication protocol of image data. Then, the medical image is communicated and displayed based on these.

In addition, DICOM specifies a Grayscale Standard Display Function (GSDF), and GSDF is a function using JND (Just Noticeable Difference) defined by the minimum luminance difference that can be identified by humans. Therefore, by correcting the gradation characteristics of the display device according to the GSDF and displaying the display, it is possible to realize a smooth and accurate grayscale display ergonomically in all the display devices.

Further, Patent Document 1 describes a brightness value when the display means is driven at the lowest drive level in an image interpretation environment, a brightness value when the display means is driven at the lowest drive level in a dark room environment, and a dark room environment. Below, a brightness adjustment method for creating a gradation correction table that corrects the gradation characteristics of the display means based on the brightness value when the test image is displayed on the display means at the measurement drive level is described.

Further, in Patent Document 2, the brightness of each gradation value of the image displayed on the display device is measured, and the similarity between the color component of the image giving the brightness and the color component of the image giving the target brightness is manually determined. If they are not similar, the target luminance for each gradation value is calculated again, and if they are similar, a correction table showing the relationship between the gradation value of each color component of the image signal and the gradation value of the image to be displayed is generated. A gradation correction method for correcting a gradation value is described.

Japanese Unexamined Patent Publication No. 2005-157260 (published on June 16, 2005) Japanese Unexamined Patent Publication No. 2011-154110 (published on August 11, 2011)

However, the above-mentioned conventional technique has the following problems. In both Patent Document 1 and Patent Document 2, a correction table is generated based on the measured brightness. However, if a change is made so that the black brightness and the white brightness change after the correction table is generated, the correction table is generated. Needs to be regenerated. Therefore, when a correction table for obtaining DICOM GSDF-compliant gradation characteristics is generated, only image data (for example, an X-ray photograph) that requires DICOM GSDF-compliant gradation characteristics is displayed in the same state. You can only let it.

The present invention has been made in view of the above problems, and an object of the present invention is to be able to output image data in which the image data to be displayed has desired gradation characteristics in accordance with the actual gradation characteristics of the display device. The purpose is to realize an image processing device and the like.

In order to solve the above problems, the image processing device according to one aspect of the present invention is an image processing device that converts the gradation characteristics of the input image data and outputs the image processing device to the display device. A gradation characteristic changing unit that changes the gradation characteristics of the image data to a desired gradation characteristic using the maximum brightness and the minimum brightness, and a changed gradation characteristic after the gradation characteristic is changed by the gradation characteristic changing unit. And the difference reflecting unit that derives the difference from the theoretical value of the desired gradation characteristic and reflects the derived difference in the gradation characteristic of the input image data, and the difference reflecting unit reflects the difference. A gamma conversion unit that performs gamma conversion according to the gradation characteristics of the display device with respect to the gradation characteristics, and an output that outputs image data of the gradation characteristics gamma-converted by the gamma conversion unit to the display device. It has a department.

Further, in order to solve the above-mentioned problems, the image processing method according to one aspect of the present invention is an image processing method that converts the gradation characteristics of the input image data and outputs the image processing method to the display device. A gradation characteristic change step for changing the gradation characteristic of the image data to a desired gradation characteristic using the maximum brightness and the minimum brightness of the device, and a post-change floor after the gradation characteristic change by the gradation characteristic change step. The difference is derived in the difference reflection step of deriving the difference between the toning characteristic and the theoretical value of the desired gradation characteristic and reflecting the derived difference in the gradation characteristic of the input image data, and the difference is reflected in the difference reflection step. A gamma conversion step that performs gamma conversion according to the gradation characteristics of the display device for the reflected gradation characteristics, and an image data of the gradation characteristics that has been gamma-converted in the gamma conversion step are output to the display device. Includes output steps and.

According to one aspect of the present invention, even if the gradation characteristic of the image data is different from the gradation characteristic of the display device, the image data can be displayed on the display device with the gradation characteristic of the image data. It plays the effect. Further, even if the gradation characteristics of the display device deviate from the original gradation characteristics, the effect is that the image data can be displayed with the gradation characteristics of the image data.

It is a block diagram which shows the main part structure of the display device which concerns on Embodiment 1 of this invention. It is a block diagram which shows the main part structure of the image correction module provided in the said display device. It is a figure for demonstrating the process which is the premise for evaluating the gradation characteristic of a display device. It is a figure for demonstrating the process which is the premise for evaluating the gradation characteristic of a display device. It is a flowchart which shows the flow of a coloring determination process. It is a figure for demonstrating whether or not it is colored. It is a figure for demonstrating whether or not it is colored. It is a flowchart which shows the flow of processing in the display device gamma conversion parameter creation part. It is a figure for demonstrating the process in the display device gamma conversion parameter creation part 212. It is a flowchart which shows the process flow in the display device correction parameter creation part and gamma change parameter creation part. It is a figure for demonstrating the process of the display device correction parameter creation part and gamma change parameter creation part. It is a figure for demonstrating the process of the display device correction parameter creation part and gamma change parameter creation part. It is a figure for demonstrating the process of the display device correction parameter creation part and gamma change parameter creation part. It is a figure for demonstrating the process of the display device correction parameter creation part and gamma change parameter creation part. It is a figure for demonstrating the process of the display device correction parameter creation part and gamma change parameter creation part. It is a figure for demonstrating the effect of this invention. It is a block diagram which shows the main part structure of the image correction module provided in the display device which concerns on Embodiment 2 of this invention. It is a flowchart which shows the flow of processing in a multi-screen conversion part. It is a figure for demonstrating the process of a multi-screen conversion part. It is a figure for demonstrating the process of a multi-screen conversion part. It is a figure for demonstrating the effect of this invention. It is a figure which shows the display device which is the premise of this invention. It is a figure which shows the gradation characteristic in the display device which is the premise of this invention. It is a figure which shows the example when the relationship between the gradation and the brightness in the display device which is the premise of this invention is visually observed through the display device.

[Embodiment 1]
[Prerequisite display device]
First, the display device that is the premise of the present invention will be described with reference to FIGS. 22 to 24.

Usually, in display devices such as televisions, information display devices, PC monitors, and projectors, gradation correction is performed according to product specifications. FIG. 23 shows an example of gradation correction. FIG. 23 shows examples of gamma 2.2, gamma 2.4, DICOM (Digital Imaging and Communications in Medicine) standard GSDF (Grayscale Standard Display Function), and gradation characteristic X. Further, FIG. 24 is a diagram showing an example when the relationship between gradation and brightness is visually observed through a display device. In FIG. 24, the brightness is represented by a single color from white to black. Examples of the display device include an LCD (Liquid Crystal Display) and an organic EL (Electro Luminescence).

FIG. 22 shows an example when the display device is an LCD. As shown in FIG. 22, in the case of an LCD, the display device includes a main control module, a timing controller, a source driver, a gate driver, and a display device.

Then, at the timing instructed by the timing controller, the source driver and the gate driver control the horizontal pixels and the pixels of the vertical line of the display device to display the display data processed by the main control module on the display device.

Then, when creating the correction table described in Patent Document 1 described above, the creation unit is implemented in the timing controller.

Further, when creating the correction table described in Patent Document 2, the creation unit is implemented in the main control module.

When the gradation characteristic of the display device is gamma 2.2, the image data created by the main control module is created so that the gradation characteristic corresponds to gamma 2.2. When the gradation characteristic of the display device conforms to the DICOM standard GSDF, the image data created by the main control module is created so that the gradation characteristic conforms to the DICOM standard GSDF.

[Display device configuration]
The configuration of the display device 100 according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a main configuration of the display device 100. As shown in FIG. 1, the display device 100 includes a main control module 10, an image correction module (image processing device) 20, a timing controller 30, a display device 40, a source driver 41, and a gate driver 42. Other than the image correction module 20, the display device is the same as the display device described as a premise. The display device 100 may or may not include the configurations of Patent Documents 1 and 2 described above.

Here, a case where an image having gradation characteristics conforming to the DICOM standard GSDF is displayed on the display device 40 will be described.

As shown in FIG. 1, in the display device 100, an image correction module 20 is provided in front of the timing controller 30. The image correction module 20 may be located on the higher side than the gradation characteristic conversion is performed so as to conform to the DICOM standard GSDF, and does not have to be immediately before the timing controller 30.

Next, the details of the image correction module 20 will be described with reference to FIG. FIG. 2 is a block diagram showing a main configuration of the image correction module 20. As shown in FIG. 2, the image correction module 20 includes a parameter creation unit 210, a display device gamma conversion unit (gamma conversion unit, output unit) 220, a display device correction unit (difference reflection unit) 230, and a gamma change unit (floor). The tuning characteristic changing unit) 240 is included. Although the configuration is described here as a configuration in which the image correction module 20 includes the parameter creation unit 210, the present invention is not limited to this, and the image correction module 20 is provided outside the image correction module 20 and is created by the external parameter creation unit 210. The parameters may be transmitted to the image correction module 20. For example, the arithmetic unit 302 described later may be provided with a parameter creation unit 210, and the image correction module 20 may be configured to acquire parameters from the arithmetic unit 302.

[Display device evaluation process]
Here, before the description of the processing by the image correction module 20, the processing that is the premise of the processing by the image correction module 20 will be described with reference to FIGS. 3 and 4. 3 and 4 are diagrams for explaining a process that is a prerequisite for evaluating the gradation characteristics of the display device 40.

As shown in FIG. 3, a luminance meter 301 is installed in front of the display device 40, predetermined image data is displayed on the display device 40, and the luminance value at that time is measured. It is desirable that the luminance meter 301 is properly calibrated, and when the display device 40 is used for displaying a medical image, it is desirable that the luminance meter 301 is used by a medical institution in an acceptance test.

As a specific processing flow, as shown in FIG. 4, after installing the luminance meter (S101), transmission of digital data (image data) is started (S102). First, the minimum gradation digital data X is transmitted (S103), and the brightness value at that time is acquired and recorded (S104). Then, the gradation value is added by the setting step α (S107), the process returns to step S103, the digital data X is transmitted, and the luminance value at that time is acquired. This is repeated until the gradation value becomes the maximum, and if the transmitted digital data has the maximum gradation (YES in S105), the transmission of the digital data is terminated (S106).

The step α to be added to the gradation of the digital data may be as long as the resolution can be decomposed. For example, when the resolution is 8 bits, it is 1. As a result, it is possible to measure from 0 to 255 for each step. In addition, according to the DICOM regulation, since it is determined by 18 patterns (eg, LN8-01 to LN8-18) from 0 to 255 every 15 steps, the step α is 15. However, when the display device 100 is set to a high control grade contrast response, or when it is desired to improve the accuracy higher than the current value of the contrast response, it is desirable to measure at a resolution that can be decomposed. Further, the above has given an example of the case of 8 bits, but the present invention is not limited to this. Decomposable resolutions such as 10 bits and 12 bits may be high, and higher resolutions are desirable.

It is also possible to measure and record not only the luminance (Lv) but also the chromaticity coordinates (Lx, Ly). By measuring the chromaticity coordinates, when coloring occurs on a display device capable of displaying colors, the chromaticity coordinates can be used for the coloring determination.

The image correction module 20 will be described again with reference to FIG.

As shown in FIG. 2, the parameter creation unit 210 includes a color correction parameter creation unit (chromaticity determination unit) 211, a display device gamma conversion parameter creation unit 212, a display device correction parameter creation unit 213, and a gamma change parameter creation unit (gamma change parameter creation unit). Gradation characteristic determination unit) 214 is included.

The color correction parameter creation unit 211 makes a color determination using the luminance and chromaticity coordinates obtained in the evaluation process of the display device 40. Then, when it is determined that there is coloring, color correction is performed. The details of the coloring correction are not mentioned in the present specification.

Next, the details of the coloring determination process will be described with reference to FIGS. 5 to 7. FIG. 5 is a flowchart showing the flow of the coloring determination process, and FIGS. 6 and 7 are diagrams for explaining whether or not the coloring is performed.

When the input gradation, which is the gradation of the input image data, is 8 bits, that is, the resolution is [0-255], the brightness and chromaticity coordinates of each gradation are measured and recorded. Then, the color correction parameter creation unit 211 calculates the maximum value (chromaticity MAX) and the minimum value (chromaticity MIN) of the chromaticity coordinates (Lx, Ly) from the input gradations 0 to 255 (S11). Next, the chromaticity range (chromaticity RANGE) is obtained by taking the difference between the calculated maximum value and the minimum value (S12). Then, the color correction parameter creation unit 211 makes a color determination depending on whether or not the obtained chromaticity range is larger than the determination value (S13). When the chromaticity range is larger than a predetermined value (YES in S13), it is determined that there is coloring, a coloring parameter is created, and coloring correction is performed (S14). Note that this specification does not refer to color correction. On the other hand, when the chromaticity range is equal to or less than a predetermined value (NO in S13), it is determined that there is no coloring, and the coloring determination is completed. Since the gradation characteristic of the DICOM standard GSDF is displayed as a single color of black and white, it is determined that there is no coloring.

Note that FIG. 6 shows an example of the chromaticity when it is determined that there is coloring, and FIG. 7 shows an example of the chromaticity when it is determined that there is no coloring. In FIGS. 6 and 7, the horizontal axis represents the gradation value and the vertical axis represents the chromaticity coordinates.

From the above, the color correction parameter creation unit 211 uses the input gradation value and the chromaticity of the image displayed on the display device 40 to determine the difference between the maximum value and the minimum value of the chromaticity between predetermined gradations. It can be said that it is determined whether or not the value exceeds a predetermined value.

The display device gamma conversion parameter creation unit 212 determines the gradation characteristic of the display device 40 and generates the gamma conversion parameter D.

A more detailed description will be given with reference to FIGS. 8 and 9. FIG. 8 is a flowchart showing a processing flow in the display device gamma conversion parameter creating unit 212, and FIG. 9 is a diagram for explaining the processing in the display device gamma conversion parameter creating unit 212.

As shown in FIG. 8, the display device gamma conversion parameter creation unit 212 first determines the brightness value when the gradation value is 0 in the measured data and the brightness when the gradation value is 0 in the gradation characteristic to be evaluated. The difference (absolute value) from the value is calculated (S201). For example, if the gradation characteristic to be evaluated is gamma 2.2, the difference from the luminance value when the gradation value is 0 in gamma 2.2 is calculated. Then, the calculated difference is set as the variable S (S202). Next, step α is added to the gradation value (S203), and similarly to step S201, the brightness value of the gradation value in the measured data and the brightness value of the gradation value in the gradation characteristic to be evaluated are set. The difference (absolute value) is calculated (S204).

For example, as shown in FIG. 9, when the measurement data gradation characteristic is "gradation characteristic a" and the gradation characteristic to be evaluated is "gradation characteristic X", the difference Ag of the brightness value in the gradation value g Is the absolute value of the difference "Xg-ag" between the brightness value Xg of the "gradation characteristic a" and the brightness value ag of the "gradation characteristic a" when the gradation value g is used.

Then, if the calculated difference is larger than the variable S (YES in S205), the difference is substituted in the variable S (S206), otherwise (NO in S205), the process proceeds to step S207 as it is. After that, the processes from step S203 to step S206 are repeated until the maximum gradation is reached. Therefore, finally, the variable S becomes the largest difference between the luminance value at each gradation in the measured data and the luminance value at each gradation in the gradation characteristic to be evaluated.

Then, the processes from step S201 to step S207 are performed for all the gradation characteristics to be evaluated (S208). That is, the gradation characteristics to be evaluated are gamma 2.2, gamma 2.4, gradation characteristics conforming to the DICOM standard GSDF, gradation characteristics A, gradation characteristics B, gradation characteristics C, and gradation characteristics. If there are seven X's, the processes from step S201 to step S207 are performed for all of them.

Then, the display device gamma conversion parameter creation unit 212 determines the gradation characteristic having the smallest variable S among all the gradation characteristics, that is, the gradation characteristic having the smallest difference (absolute value) as the gradation characteristic of the display device 40. Then, the gamma conversion parameter D corresponding to the gradation characteristic is generated. Since the gradation characteristics conforming to gamma 2.2 and DICOM standard GSDF can be theoretically calculated, the difference is calculated by comparing the theoretically calculated values with the measured data.

The display device correction parameter creation unit 213 creates the display device correction parameter C used by the display device correction unit 230.

Further, the gamma change parameter creation unit 214 creates the gamma change parameter B used by the gamma change unit 240.

The details of the processing in the display device correction parameter creation unit 213 and the gamma change parameter creation unit 214 will be described with reference to FIGS. 10 to 15.

FIG. 10 is a flowchart showing a processing flow in the display device correction parameter creation unit 213 and the gamma change parameter creation unit 214, and FIGS. 11 to 15 show the display device correction parameter creation unit 213 and the gamma change parameter creation unit 214. It is a figure for demonstrating the process.

First, the display device correction parameter creation unit 213 performs a process of expanding the gradation characteristic of the measurement data (S301). For example, when the gradation is expanded from 8 bits to 10 bits, it is expanded to 10 bits by linearly interpolating between n gradations and n + 1 gradations in 8 bits. FIG. 11 shows an example of linear interpolation. As shown in FIG. 11, when the gradation characteristics of the measurement data are expressed as they are in a graph, steps are formed between the gradations and the graph becomes jagged. It can be seen that the graph showing the characteristics becomes smooth.

Next, the gamma change parameter creation unit 214 uses the following mathematical formula to set the luminance value at gradation 0 in the expanded measurement data as the minimum luminance and the luminance at gradation 255 as the maximum luminance, and use the following mathematical formula to JND. (Just Noticeable Difference) Conversion is performed (S311).

Here, Log10 represents the logarithm to the base 10. Then, A = 71.498068, B = 94.593053, C = 41.912053, D = 9.8247004, E = 0.28175407, F = -1.1878455, G = -0.18014349, H = 0.14710899, I = -0.017046845.

The above formula is a formula described in the DICOM standard, and is a formula for obtaining the JND index for the luminance value in a specific range.

As a result, the maximum value and the minimum value of the JND index are calculated.

Next, the gamma change parameter creation unit 214 calculates each step of JND from the maximum value and the minimum value of the JND index based on the following formula (S312).
(JND _{MAX- JND MIN} ) / Total number of JND steps x JND steps (n) + JND _MIN
Next, the gamma change parameter creation unit 214 calculates the brightness from the value of each step of JND calculated in step S312 using the following mathematical formula (S313).

Here, Ln indicates the natural logarithm, and j indicates the index (1 to 1023) of the luminance level Lj of JND. And a = -1.3011877, b = -2.5840191E-2, c = 8.0242636E-2, d = -1.0320229E-1, e = 1.3646699E-1, f = 2.8745620E-2, g = -2.5468404E- 2, h = -3.1978977E-3, k = 1.2992634E-4, m = 1.3635334E-3.

The above formula is a formula described in the DICOM standard, and is a formula for obtaining the brightness as a function of the JND index. As a result, gradation characteristics conforming to the DICOM standard GSDF are required. Here, this gradation characteristic is referred to as a target DICOM standard GSDF. An example of the target DICOM standard GSDF is shown in FIG. Then, the gamma change parameter creation unit 214 creates a gradation characteristic conforming to the target DICOM standard GSDF as the gamma change parameter B (S314).

On the other hand, the display device correction parameter creation unit 213 generates the target gradation characteristic Y (S302), and uses the generated target gradation characteristic Y as the gradation characteristic of the target DICOM standard GSDF generated in step S313 and the display device 40. Gradation characteristic Y'is generated by conversion using (theoretical gradation). Further, the gradation characteristic X'is generated by converting the target gradation characteristic Y with the GSDF of the target DICOM standard and the gradation characteristic X obtained by expanding the gradation characteristic of the measurement data (S303). These processes are shown in FIG.

Next, the display device correction parameter creation unit 213 performs and records the gradation characteristic X'-gradation characteristic Y'for each gradation step of the DICOM standard GSDF (S304). A portion of the recorded error is shown in FIG. If the recording capacity is limited, the recording of the parameter B created by the gamma change parameter creation unit 214 may be omitted. This is because the target DICOM standard GSDF can be calculated separately using the measured gradation characteristics. Then, the display device correction parameter creation unit 213 sets the difference calculated by X'-Y'in each gradation as the display device correction parameter C (S305). By re-measuring the brightness value of the measurement data after a while, calculating the difference, and comparing it with the previously calculated difference, it can also be used to determine the change with time of the display device 40.

As described above, the gamma change parameter B, the display device correction parameter C, and the display device gamma conversion parameter D are created.

Next, the processing in the display device gamma conversion unit 220, the display device correction unit 230, and the gamma changing unit 240 of the image correction module 20 will be described. By performing gradation characteristic conversion on the input image data, even if the gradation characteristic of the display device 40 is different from the gradation characteristic of the image data, the image data is displayed on the display device 40. It enables display with the gradation characteristics of data. Since the processing for the image data is performed in the order of the gamma changing unit 240, the display device correction unit 230, and the display device gamma conversion unit 220, the description will be given in this order.

The gamma change unit 240 uses the gamma change parameter B created by the gamma change parameter creation unit 214 to convert the gradation characteristics of the input image data into gradation characteristics conforming to the DICOM standard GSDF.

The display device correction unit 230 reflects the difference indicated by the display device correction parameter C created by the display device correction parameter creation unit 213 in the gradation characteristics converted by the gamma change unit 240.

The display device gamma conversion unit 220 uses the display device gamma conversion parameter D so that the display device correction unit 230 can properly display the image data in which the difference is reflected in the gradation characteristics on the display device 40. The gradation characteristic of the image data is made to correspond to the gradation characteristic (gamma characteristic) of the display device 40. Specifically, for example, gamma conversion is performed according to the gradation characteristics shown in FIG. Then, the image data after converting the gradation characteristics is transmitted to the display device 40.

As described above, in the display device 100 according to the present embodiment, the display device 40 has a gradation characteristic of gamma 2.2, and the image data has a gradation characteristic conforming to the DICOM standard GSDF. Even in this case, it is not necessary to implement the amendment table described in Patent Document 1. The display device gamma conversion unit 220 appropriately converts the gradation characteristics, and even the display device 40 having the gradation characteristics of gamma 2.2 can display the image data with the gradation characteristics conforming to the DICOM standard GSDF. This is because it is displayed. That is, the display device 40 having a gradation characteristic of gamma 2.2 can be used as a medical monitor for appropriate display.

As described above, in the display device 100 according to the present embodiment, as shown in FIG. 16, even if the gradation characteristic of the display device 40 is, for example, gamma 2.2, the display device 40 is a DICOM standard GSDF. Image data having gradation characteristics conforming to the above can be displayed with gradation characteristics conforming to the DICOM standard GSDF.

As described above, the image correction module 20 according to the present embodiment converts the gradation characteristic of the input image data and outputs it to the display device 40, and uses the maximum brightness and the minimum brightness of the display device 40. Then, the gamma changing unit 240 that changes the gradation characteristic of the image data to the desired gradation characteristic, and the difference between the changed gradation characteristic after the gradation characteristic change and the theoretical value of the desired gradation characteristic are derived. , The display device correction unit 230 that reflects the derived difference in the gradation characteristics of the input image data, and the gradation characteristics that reflect the differences are gamma-converted according to the gradation characteristics of the display device 40. It includes a display device gamma conversion unit 220 that outputs gamma-converted image data of gradation characteristics to the display device 40.

As a result, once the parameters are set in the parameter creation unit 210 of the image correction module 20, even if the correction table described in Patent Documents 1 and 2 is used, the correction table is not changed thereafter. In a display device having a gradation characteristic different from the gradation characteristic of the image data, the image data can be displayed with the gradation characteristic of the image data. Further, even if the gradation characteristic of the display device 40 deviates from the original gradation characteristic, the image data can be displayed by the gradation characteristic of the image data.

Further, since the parameters used in the processing of each part are set for each display device, even if there are variations in the characteristics of each display device, it can be appropriately dealt with.

Further, since the gradation characteristics of the image data displayed on the display device 40 can be made appropriate, the management grade as a medical monitor can be improved.

[Embodiment 2]
Other embodiments of the present invention will be described below. For convenience of explanation, the members having the same functions as the members described in the above-described embodiment are designated by the same reference numerals, and the description thereof will not be repeated.

As shown in FIG. 17, the present embodiment is different from the first embodiment in that the image correction module (image processing device) 20A includes a plurality of screen conversion units (arrangement determination units) 250.

When a plurality of image data are input to the display device 40, the image data corresponding to the gradation characteristics of the display device 40 is displayed appropriately, but the other image data is not displayed appropriately.

Therefore, in the present embodiment, the image correction module 20A is provided with a plurality of screen conversion units 250 so that even when a plurality of image data are input, each image data is appropriately displayed on the display device 40. ing.

The multiple screen conversion unit 250 sets a display area of the display device 40 for each image data of a plurality of image data having different gradation characteristics, and associates the display area with the gradation characteristics.

This will be described in detail with reference to FIGS. 18 to 20. FIG. 18 is a flowchart showing the flow of processing in the multi-screen conversion unit 250, and FIGS. 19 and 20 are diagrams for explaining the processing of the multi-screen conversion unit 250.

As shown in FIG. 18, when a plurality of image data having different gradation characteristics are input (S401), the plurality of screen conversion units 250 assign IDs according to the respective inputs (S402). The image data includes image resolution, frame frequency, accompanying signals, etc. For example, HDMI (registered trademark) includes content protection information such as HDCP1.4 and HDCP2.1, luminance information, audio dug, and the like. Is done. In addition, the medical image includes information called a DICOM tag, information associated with the imaging data such as the date of imaging, a person's name, and age. Further, ID is assigned to the input of the input I / F other than the input of the video signal such as I2C and SPI I / F. FIG. 20 shows an example of an ID-assigned information table. In the example of the information table 2001 shown in FIG. 20, IDs 1 to ID 6 are assigned to the six image data, and for each of them, I / F, gradation characteristics, resolution, frame frequency, content protection, maximum brightness [ cd / m ² ], audio tag, DICOM tag, layout coordinates, α blend [%] are associated.

Next, the multi-screen conversion unit 250 stores the ID-assigned information in the memory together with the image data (S403).

Next, the plurality of screen conversion units 250 configure the screen layout (S404). In the screen layout configuration, the layout configuration is determined for one output screen. FIG. 19 shows an example of the layout configuration. As shown in FIG. 19, the layout configuration is determined by the layout information indicating the coordinates of one point. That is, the horizontal width (Width) and height (Height) are determined according to the points indicated by the coordinates of one point. Note that only the layout information of one screen is determined here, and the input image data is not lost.

Next, the multi-screen conversion unit 250 performs a memory call process (S405). In the memory call, the image data is called from the memory according to the determined layout information. At this time, the image is enlarged, reduced, and magnified according to the horizontal width and height of the image display area. Since these treatments can be performed using known techniques, the details thereof will not be described here. FIG. 19 shows an example in which the layout configuration is determined according to the layout information. In the example shown in FIG. 19, a display area corresponding to ID1, ID2, ID5, and ID6 is shown on the display device 40. As shown in FIG. 19, it is also possible to overlap the display areas. Even in this case, various information is not lost. Further, since the alpha blend information (transparency information) is also determined for each ID, the transparency processing is also performed according to each display area.

The layout configuration can be changed at any time. In this case, the memory is called according to the changed layout information.

Then, the gamma changing unit 240, the display device correction unit 230, and the display device gamma conversion unit 220 perform processing for each ID called in the memory calling process of the plurality of screen conversion units 250.

As a result, according to the present embodiment, it is possible to display each image data with appropriate gradation characteristics in each display area of the display device 40.

For example, as shown in FIG. 21, even when a plurality of image data having different gradation characteristics are input to the display device 40 having a gradation characteristic of gamma 2.2, each display area on the display device 40 In addition, each image data can be displayed with appropriate gradation characteristics.

Further, the image data is not limited to black and white, and can be displayed in color.

[Example of realization by software]
The control block of the display device 100 (particularly, the main control module 10, the image correction module 20, and the timing controller 30) may be realized by a logic circuit (hardware) formed in an integrated circuit (IC chip) or the like. It may be realized by software.

In the latter case, the display device 100 includes a computer that executes instructions of a program that is software that realizes each function. This computer includes, for example, at least one processor (control device) and at least one computer-readable recording medium that stores the program. Then, in the computer, the processor reads the program from the recording medium and executes it, thereby achieving the object of the present invention. As the processor, for example, a CPU (Central Processing Unit) can be used. As the recording medium, a "non-temporary tangible medium", for example, a ROM (Read Only Memory) or the like, a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. Further, a RAM (Random Access Memory) for expanding the above program may be further provided. Further, the program may be supplied to the computer via an arbitrary transmission medium (communication network, broadcast wave, etc.) capable of transmitting the program. It should be noted that one aspect of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the above program is embodied by electronic transmission.

〔summary〕
The image processing device according to the first aspect of the present invention is an image processing device that converts the gradation characteristics of the input image data and outputs the image processing device to the display device, using the maximum brightness and the minimum brightness of the display device. A gradation characteristic changing unit that changes the gradation characteristics of the image data to a desired gradation characteristic, a changed gradation characteristic after the gradation characteristic is changed by the gradation characteristic changing unit, and a theory of the desired gradation characteristic. The display of the difference reflecting unit that derives the difference from the value and reflects the derived difference in the gradation characteristics of the input image data, and the gradation characteristics that the difference is reflected in the difference reflecting unit. It includes a gamma conversion unit that performs gamma conversion according to the gradation characteristics of the device, and an output unit that outputs image data of the gradation characteristics gamma-converted by the gamma conversion unit to the display device.

According to the above configuration, the gradation characteristics are converted using the actual gradation characteristics of the display device and the gradation characteristics of the image data, so that the gradation characteristics of the image data are the gradation characteristics of the display device. Even if it is different from the above, the display device can display the image data with the gradation characteristics of the image data.

Further, even if the gradation characteristic of the display device deviates from the original gradation characteristic, the image data can be displayed by the gradation characteristic of the image data. That is, it is possible to output the image data having the desired gradation characteristics of the image data to be displayed to the display device in correspondence with the actual gradation characteristics of the display device.

The image processing apparatus according to the second aspect of the present invention has the relationship between the input gradation value and the brightness of the image displayed on the display device in the first aspect, and each of a plurality of predetermined gradation characteristics. A gradation characteristic determination unit for determining the gradation characteristics of the display device is provided by using the difference between the above, and the gamma conversion unit performs gamma conversion according to the gradation characteristics determined by the gradation characteristic determination unit. It may be a thing.

According to the above configuration, the actual gradation characteristics of the display device can be appropriately determined. Therefore, the gradation characteristic can be converted according to the actual gradation characteristic of the display device.

In the image processing apparatus according to the third aspect of the present invention, in the above aspect 1 or 2, the desired gradation characteristic is the grayscale standard display function (GSDF: Grayscale Standard Display Function) of the DICOM (Digital Imaging and Communication in Medicine) standard. ) Is compliant, and the gradation characteristic changing unit sets the discrimination area (JND: Just-Noticeable Difference) index derived from the maximum brightness and the minimum brightness of the display device to the brightness indicated by the grayscale standard display function. By converting, the gradation characteristic of the image data may be changed to a desired gradation characteristic.

According to the above configuration, the image data can be displayed on the display device with the gradation characteristics conforming to the grayscale standard display function (GSDF) of the DICOM standard regardless of the gradation characteristics of the display device.

The image processing apparatus according to the fourth aspect of the present invention uses the input gradation value and the chromaticity of the image displayed on the display device in any one of the above aspects 1 to 3 to obtain the said image among predetermined gradations. It may be provided with a chromaticity determination unit for determining whether or not the difference between the maximum value and the minimum value of chromaticity exceeds a predetermined value.

According to the above configuration, it is determined whether or not the difference between the maximum value and the minimum value of the chromaticity between the predetermined gradations exceeds the predetermined value, so that white and black can be appropriately expressed and coloring is suppressed. be able to.

In the image processing apparatus according to the fifth aspect of the present invention, in any one of the first to fourth aspects, the input image data is a plurality of image data having different gradation characteristics, and the plurality of image data are obtained from each of the plurality of image data. The arrangement determining unit for displaying in a predetermined area of the display device is provided, and for each area in which the image data is displayed, the gradation characteristic changing unit desires the gradation characteristic of the image data for the corresponding image data. The difference was changed to the gradation characteristic, the difference reflecting unit reflected the derived difference, the gamma conversion unit performed gamma conversion according to the gradation characteristic of the display device, and the output unit was gamma-converted. The image data of the gradation characteristic may be output.

According to the above configuration, even when a plurality of image data having different gradation characteristics are input, each image data data is displayed with each gradation characteristic regardless of the gradation characteristic of the display device. Can be displayed on.

The image processing method according to aspect 6 of the present invention is an image processing method that converts the gradation characteristics of the input image data and outputs the image data to the display device, using the maximum brightness and the minimum brightness of the display device. The theory of the gradation characteristic changing step for changing the gradation characteristic of the image data to the desired gradation characteristic, the changed gradation characteristic after the gradation characteristic is changed by the gradation characteristic changing step, and the desired gradation characteristic. The display of the difference reflection step in which the difference from the value is derived and the derived difference is reflected in the gradation characteristic of the input image data, and the gradation characteristic in which the difference is reflected in the difference reflection step. The gamma conversion step of performing gamma conversion according to the gradation characteristics of the device and the output step of outputting the image data of the gradation characteristics gamma-converted in the gamma conversion step to the display device are included.

The image processing device according to each aspect of the present invention may be realized by a computer. In this case, the image processing device is made into a computer by operating the computer as each part (software element) included in the image processing device. The control program of the image processing device to be realized and the computer-readable recording medium on which the control program is recorded also fall within the scope of the present invention.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment.

10 Main control module 20, 20A Image correction module (image processing device)
30 Timing controller 40 Display device 41 Source driver 42 Gate driver 100 Display device 210 Parameter creation unit 211 Correction parameter creation unit (chromaticity determination unit)
212 Display device gamma conversion parameter creation unit 213 Display device correction parameter creation unit 214 Gamma change parameter creation unit (gradation characteristic determination unit)
220 Display device Gamma conversion unit (gamma conversion unit, output unit)
230 Display device correction unit (difference reflection unit)
240 Gamma change part (gradation characteristic change part)
250 Multiple screen conversion unit (arrangement determination unit)
301 Luminance meter 302 Arithmetic

Claims (11)

An image processing device that converts the gradation characteristics of input image data and outputs it to a display device.
A gradation characteristic changing unit that changes the gradation characteristic of the image data to a desired gradation characteristic by using the maximum brightness and the minimum brightness of the display device.
The difference between the changed gradation characteristic after the gradation characteristic is changed by the gradation characteristic changing unit and the theoretical value of the desired gradation characteristic is derived, and the derived difference is used as the gradation characteristic of the input image data. Difference reflection part to reflect and
A gamma conversion unit that performs gamma conversion according to the gradation characteristics of the display device with respect to the gradation characteristics in which the difference is reflected by the difference reflection unit.
An image processing device including an output unit that outputs image data having gradation characteristics gamma-converted by the gamma conversion unit to the display device. A floor for determining the gradation characteristics of the display device by using the relationship between the input gradation value and the brightness of the image displayed on the display device and the difference between each of a plurality of predetermined gradation characteristics. Equipped with a tuning characteristic judgment unit
The image processing apparatus according to claim 1, wherein the gamma conversion unit performs gamma conversion according to the gradation characteristics determined by the gradation characteristic determination unit. The desired gradation characteristics conform to the Grayscale Standard Display Function (GSDF) of the DICOM (Digital Imaging and Communication in Medicine) standard.
The gradation characteristic changing unit converts the discrimination area (JND: Just-Noticeable Difference) index derived from the maximum brightness and the minimum brightness of the display device into the brightness indicated by the grayscale standard display function, thereby converting the image data. The image processing apparatus according to claim 1 or 2, wherein the gradation characteristic of the above is changed to a desired gradation characteristic. Using the input gradation value and the chromaticity of the image displayed on the display device, it is determined whether or not the difference between the maximum value and the minimum value of the chromaticity between the predetermined gradations exceeds the predetermined value. The image processing apparatus according to any one of claims 1 to 3, further comprising a chromaticity determination unit. The input image data is a plurality of image data having different gradation characteristics.
Each of the plurality of image data is provided with an arrangement determination unit for displaying in a predetermined area of the display device.
For each area where the image data is displayed, for the corresponding image data
The gradation characteristic changing unit changes the gradation characteristic of the image data to a desired gradation characteristic.
The difference reflection unit reflects the derived difference and
The gamma conversion unit performs gamma conversion according to the gradation characteristics of the display device, and performs gamma conversion.
The image processing apparatus according to any one of claims 1 to 4, wherein the output unit outputs the image data having a gradation characteristic that has been gamma-converted. This is an image processing method that converts the gradation characteristics of the input image data and outputs it to the display device.
A gradation characteristic change step of changing the gradation characteristic of the image data to a desired gradation characteristic by using the maximum brightness and the minimum brightness of the display device, and
The difference between the changed gradation characteristic after the gradation characteristic is changed by the gradation characteristic changing step and the theoretical value of the desired gradation characteristic is derived, and the derived difference is used as the gradation characteristic of the input image data. Difference reflection step to reflect and
A gamma conversion step that performs gamma conversion according to the gradation characteristics of the display device with respect to the gradation characteristics in which the difference is reflected in the difference reflection step.
An image processing method comprising an output step of outputting image data having gradation characteristics gamma-converted in the gamma conversion step to the display device. A floor for determining the gradation characteristics of the display device by using the relationship between the input gradation value and the brightness of the image displayed on the display device and the difference between each of a plurality of predetermined gradation characteristics. Including toning characteristic determination step
The image processing method according to claim 6, wherein in the gamma conversion step, gamma conversion is performed according to the gradation characteristic determined in the gradation characteristic determination step. The desired gradation characteristics conform to the Grayscale Standard Display Function (GSDF) of the DICOM (Digital Imaging and Communication in Medicine) standard.
In the gradation characteristic change step, the image data is obtained by converting the just-noticeable difference (JND) index derived from the maximum brightness and the minimum brightness of the display device into the brightness indicated by the grayscale standard display function. The image processing method according to claim 6 or 7, wherein the gradation characteristic of the above is changed to a desired gradation characteristic. Using the input gradation value and the chromaticity of the image displayed on the display device, it is determined whether or not the difference between the maximum value and the minimum value of the chromaticity between the predetermined gradations exceeds the predetermined value. The image processing method according to any one of claims 6 to 8, further comprising a chromaticity determination step. The input image data is a plurality of image data having different gradation characteristics.
Each of the plurality of image data includes an arrangement determination step of displaying the plurality of image data in a predetermined area of the display device.
For each area where the image data is displayed, for the corresponding image data
In the gradation characteristic changing step, the gradation characteristic of the image data is changed to a desired gradation characteristic.
In the difference reflection step, the derived difference is reflected.
In the gamma conversion step, gamma conversion is performed according to the gradation characteristics of the display device.
The image processing method according to any one of claims 6 to 9, wherein in the output step, the image data having the gradation characteristics converted into gamma is output. The control program for operating a computer as the image processing device according to claim 1, wherein the computer functions as the gradation characteristic changing unit, the difference reflecting unit, and the gamma conversion unit.

Images