JP2004088620A - Monitor luminance adjustment method, apparatus theerof and image observation apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a monitor luminance adjustment method, a monitor luminance adjustment apparatus and an image observation apparatus for an easy operation of adjusting luminance of a monitor, so that luminance of the monitor changes approximately with changes of concentration of a film. <P>SOLUTION: The monitor luminance adjustment is attained by detecting changes in the density of a film printed with a test pattern (S2 and S3), detecting changes in the luminance of the monitor displaying the test pattern (S7 and S8), and correcting tone luminance conversion characteristics of the monitor so that the detected luminance changes match with or come close to the detected concentration changes (S4 and S11). <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a monitor brightness adjustment method for adjusting monitor brightness, a monitor brightness adjustment device, and an image observation device.
[0002]
[Prior art]
The digitization of diagnostic imaging devices has evolved with the evolution of film imagers. In the past, CRT multi-format cameras were typical for image output, but in recent years, film imagers using semiconductor lasers, which greatly surpass image quality and operability, occupy the mainstream.
[0003]
The film imager is largely composed of a signal processing unit, a laser scanning unit, and an automatic developing unit. When image data to be output is sent to a film imager directly or indirectly from an X-ray CT apparatus, DSA (Digital Subtraction Angiography), or an MRI apparatus or via a PACS or the like, first, a signal processing unit performs film processing. Are interpolated according to the print size of the image, and the gradation is converted in accordance with the gradation / density conversion characteristics. The gradation-converted image data is converted into an analog signal, the laser output is adjusted according to the amplitude, and the film is exposed at a density corresponding to the output.
[0004]
The tone / density conversion is set according to the tone / density characteristics of the film, the type of image, the purpose of diagnosis, and the user's preference. The user's preference means an operation of operating a tone curve representing characteristics of an output density with respect to an input tone to adjust a width of a region where a density change is emphasized, a center tone, and the like so that a desired output result is obtained. Normally, the trial is repeated in the early stage of the introduction of the film imager to finally determine the gradation conversion characteristics. The determined gradation conversion characteristics are fixed in order to eliminate variations in film density due to the preference of doctors and image readers and to unify image reading quality.
[0005]
On the other hand, image interpretation is sometimes performed not only on a film but also on a monitor such as an image observation device. It is expected that the resolution and display gradation of the monitor will be similar to those of the film with the development of technology in the future, and it is expected that the chance of outputting to the film will be further reduced.
[0006]
Generally, it is known that the luminance characteristic of a monitor changes exponentially with respect to an input gradation. Image data is subjected to gradation conversion using a gamma correction characteristic in order to linearly change the output luminance gradation with respect to the input gradation.
[0007]
In order to use the monitor for image interpretation, it is necessary to set the gradation / luminance characteristics approximately to the gradation / density characteristics of the film. However, there is a problem that the work of approximating the gradation / luminance characteristics of the monitor to the gradation / density characteristics of the film requires a great deal of work and that individual differences easily occur.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to provide a monitor brightness adjustment method, a monitor brightness adjustment device, and an image observation device that facilitate the operation of adjusting the monitor brightness so that the monitor brightness changes approximately in response to a change in film density. Is to do.
[0009]
[Means for Solving the Problems]
The monitor brightness adjusting method according to the first aspect of the present invention detects a density change of a film on which a test pattern is printed, detects a brightness change of a monitor on which the test pattern is displayed, and responds to the detected density change. Then, the gradation-luminance conversion characteristics of the monitor are corrected so that the detected luminance changes match or approximate.
The monitor brightness adjusting method according to the second aspect of the present invention includes detecting a density of a film on which a test pattern is printed at a plurality of locations, generating a tone / density characteristic based on the detected density of the plurality of locations, The luminance of the monitor on which the test pattern is displayed is detected at a plurality of locations, and a gradation / luminance characteristic is generated based on the detected luminances of the plurality of locations, and the generated gradation / density characteristic is generated with respect to the generated gradation / density characteristic. The gradation / luminance conversion characteristics of the monitor are corrected based on the deviation of the gradation / luminance characteristics.
The monitor brightness adjusting method according to the third aspect of the present invention detects a density of a film on which a test pattern is printed according to test pattern data at a plurality of locations, and adjusts a gradation / density characteristic based on the detected density at the plurality of locations. Generating the tone / density characteristics of the monitor based on the generated tone / density characteristics, and displaying a test pattern in accordance with the test pattern data subjected to the tone conversion by the corrected tone / luminance conversion characteristics. The detected luminance of the monitor is detected at a plurality of locations, and a gradation / luminance characteristic is generated based on the detected luminances of the plurality of locations. The tone-luminance conversion characteristic of the monitor is re-corrected based on the deviation of the luminance characteristic.
A monitor brightness adjusting device according to a fourth aspect of the present invention includes a density sensor that detects a change in the density of a film on which a test pattern is printed, a brightness sensor that detects a change in the brightness of a monitor on which the test pattern is displayed, A correction unit that corrects the gradation-luminance conversion characteristic of the monitor so that the detected luminance change matches or approximates the detected density change.
According to a fifth aspect of the present invention, there is provided a monitor brightness adjusting device for detecting a density of a film on which a test pattern is printed at a plurality of locations, and generating a tone / density characteristic based on the detected density at the plurality of locations. A tone / density characteristic generator, a brightness sensor for detecting the brightness of the monitor on which the test pattern is displayed at a plurality of locations, and a tone / brightness characteristic based on the detected brightness at the plurality of locations. A gradation / luminance characteristic generation unit; and a correction unit for correcting a gradation / luminance conversion characteristic of the monitor based on a deviation of the generated gradation / luminance characteristic from the generated gradation / density characteristic. I do.
A monitor brightness adjusting device according to a sixth aspect of the present invention includes a density sensor that detects the density of a film on which a test pattern is printed in accordance with test pattern data at a plurality of locations, and a gradation / tone based on the detected densities of the plurality of locations. A gradation / density characteristic generation unit for generating a density characteristic, a correction unit for correcting a gradation / luminance conversion characteristic of a monitor based on the generated gradation / density characteristic, and the corrected gradation / luminance conversion characteristic A luminance sensor for detecting the luminance of a monitor on which a test pattern is displayed in accordance with the test pattern data subjected to gradation conversion at a plurality of locations, and a floor for generating a gradation / luminance characteristic based on the detected luminances of the plurality of locations. A tone / luminance characteristic generation unit, which calculates a difference between the generated grayscale / luminance characteristics with respect to the generated grayscale / density characteristics, and based on the calculated difference, ; And a calculation unit for re-correcting the gradation luminance conversion characteristics of the monitor Tadashibu.
According to a seventh aspect of the present invention, there is provided an image observation device, comprising: an input unit for inputting image data; a gradation conversion unit for performing gradation conversion on the image data according to a gradation-luminance conversion characteristic; A monitor to be displayed, and an image observing device having a monitor brightness adjustment unit for correcting the gradation brightness conversion characteristic, wherein the monitor brightness adjustment unit detects a density change of a film on which a test pattern is printed, and a density sensor. A luminance sensor for detecting a luminance change of the monitor on which the test pattern is displayed, and correcting the gradation / luminance conversion characteristic so that the detected luminance change matches or approximates the detected density change. A correction unit.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. SUMMARY OF THE INVENTION An object of the present invention is to facilitate the operation of adjusting the monitor brightness so that the monitor brightness changes approximately in response to a change in film density. Specifically, a monitor brightness adjustment method therefor is provided. Can be provided by a monitor brightness adjustment device and an image observation device having the function.
[0011]
FIG. 1 shows a configuration of a monitor brightness adjusting device according to the present embodiment. The monitor brightness adjustment device 10 constitutes, for example, a hospital LAN 60 together with the image generation device 20, the film imager 30, the image storage communication device (PACS) 40, the image observation device 50, and the like. The monitor brightness adjustment device 10 has a function of automatically adjusting the brightness of the monitor so that the brightness of the monitor changes approximately in response to a change in the density of the film printed and output by the film imager 30. This function may be configured independently as the monitor brightness adjustment device 10 or may be provided in the image generation device 20 or the image observation device 50. Here, the former example will be described.
[0012]
The image generating apparatus 20 generates image data of, for example, X-ray computed tomography (X-ray CT apparatus), DSA (Digital Subtraction Angiography) apparatus, magnetic resonance imaging apparatus (MRI apparatus), gamma camera, SPECT, PET, and the like. Device. FIG. 1 shows an X-ray CT apparatus as an example. In that example, an image generating apparatus 20 includes a system controller 21 as a center, a gantry 22 having an X-ray tube and an X-ray detector, and an X-ray detector. A reconstruction processing unit 23 for reconstructing image data based on the data including the X-ray attenuation information of the subject detected by the above; a gradation conversion unit for performing gradation conversion on the image data according to a gamma correction characteristic unique to the monitor 25 24, a monitor 25 for displaying image data subjected to gradation conversion, and an input / output interface 26 for forming a connection environment with other devices via the LAN 60. This image data is sent to the image storage communication device 40, stored in a large-capacity storage medium such as a magneto-optical disk, and directly from the image generation device 20 or via the image storage communication device 40 as required. And supplied to the image observation device 50 and the film imager 30.
[0013]
The image observation device 50 is an image display device for inputting image data stored in the image storage communication device 40 via the interface 52 and displaying the image data for image reading and the like. Are provided with a plurality of monitors 55 and 57 so that can be displayed simultaneously. The image observation device 50 includes monitors 55 and 57, and tone converters 54 and 56 connected to the monitors 55 and 57, respectively, together with the system controller 51, to create a more useful and easy-to-view emphasized image from the image data, Usually, an image processing unit 53 for performing various mathematical operations on digitized image data in order to cause a machine to perform a human interpretation and recognition work is provided. The tone converters 54 and 56 convert the tone of the image data according to the gamma correction characteristics unique to the corresponding monitors 55 and 57, respectively.
[0014]
The film imager 30 is an output device for inputting image data stored in the image storage communication device 40 via the interface 35 and printing the input image data on a film. An image processing unit 32 for interpolating according to the print size and performing gradation conversion according to the gradation / density conversion characteristics, a laser scanning unit 33, and an automatic developing unit 34 are provided. The laser scanning unit 33 is the most important part for determining the output image quality. The A / D converter converts the digital signal of the processed image into a laser power modulation signal, and converts the laser light generated from the laser light source. Scan uniformly on the film by a scanning mechanism including a polarizer, a lens, and a mirror. The film exposed by the laser irradiation is sent to an automatic developing device 34 and developed. As described above, the tone / density conversion is fixedly set according to the tone / density characteristics of the film, the type of image, the purpose of diagnosis, and the user's preference. Irrespective of the preference of doctors and image interpreters, a constant film density and its change are always realized for the input gradation.
[0015]
A monitor brightness adjusting device 10 is provided for the purpose of easily approximating the display brightness of the monitors 25, 55, 57 and the like and the change thereof with respect to the film density and its change.
[0016]
The monitor brightness adjusting device 10 includes, together with the system controller 11 and the interface 12, a test pattern data storage unit 13 that stores test pattern data in which gradation changes continuously or stepwise in one direction as shown in FIG. The film density sensor 14 detects the density of a plurality of discrete points (see FIG. 3) on the film printed and output by the film imager 30 according to the data. The density of the discrete points detected by the density sensor 14 is used as the input gradation of the test pattern data. A tone / density generating unit 17 and a tone / density generating unit 17 for generating a tone / density characteristic for associating the relationship between the entrance and the exit of the film imager 30 by associating and interpolating the density between discrete points. Monitors 25, 55, 57 according to the gradation / density characteristics of the film imager 30 generated by It generates data for correcting the gamma correction characteristic of the gradation conversion unit 24,54,56 in respectively have a gamma correction characteristic correcting unit 18. That is, the gamma correction characteristic correction unit 18 matches or approximates the gradation / luminance characteristics of the monitors 25, 55, and 57 with the gradation / density characteristics of the film imager 30 that has already been optimized at the time of introduction. As described above, the gamma correction characteristics of each of the tone converters 24, 54, 56 are corrected or data for correction is generated.
[0017]
The gamma correction characteristics of the tone converters 24, 54, and 56 are provided as a table that initially determines the assignment of output tones to input tones in the tone converter set according to the gamma characteristics of the monitor. For example, the drive voltage of the electron gun is adjusted according to the output gradation. Generally, the actual luminance with respect to this drive voltage, that is, the actual monitor luminance with respect to the output gradation of the gradation conversion unit is not linear, and each monitor has a unique characteristic. The correction of the gamma correction characteristic is performed on the assumption that the monitor luminance for the output gradation is linear. Therefore, the corrected monitors 25, 55, and 55 are corrected for the gradation / density characteristic of the film imager 30. In many cases, deviation occurs in the gradation / luminance characteristics of each of the 57 pixels. In order to eliminate or reduce this deviation, a luminance sensor 16 for detecting the actual luminance of the monitors 25, 55, 57 is provided.
[0018]
The luminance sensor 16 is configured to detect the luminance of a plurality of discrete points (see FIG. 4) on the screen of the test pattern displayed on the monitors 25, 55, and 57 according to the test pattern data in the test pattern data storage unit 13. Have been. The gradation / luminance generation unit 17 associates the monitor luminance of the discrete points detected by the luminance sensor 16 with the input gradation of the test pattern data, and interpolates the luminance between the discrete points to thereby enter the gradation conversion entrance and the monitor exit. And a gradation / luminance characteristic that associates with the relationship.
[0019]
The characteristic difference calculation unit 19 calculates the deviation (difference) of the gradation / luminance characteristics with respect to the gradation / density characteristics of the film for each gradation, and based on the calculated difference, the gamma correction characteristic correction unit 18 sends the monitor 25, Data necessary for re-correcting the gamma correction characteristics of 55 and 57 is generated.
[0020]
FIG. 5 shows a procedure of the monitor brightness adjusting method according to the present embodiment. First, the test pattern data (see FIG. 3) stored in the test pattern data storage unit 13 of the monitor brightness adjustment device 10 is read out under the control of the system controller 11 and supplied to the film imager 30 (S1). In the film imager 30, in the image processing unit 32, the gradation of the supplied test pattern data is converted according to a predetermined gradation / density conversion characteristic and printed. As shown in FIG. 3, the density at a plurality of discrete locations on the film on which the test pattern is printed is detected by the density sensor 14 (S2). Next, in the gradation / density generation unit 17, as shown in FIG. 6, the density of the discrete points detected by the density sensor 14 is associated with the input gradation of the test pattern data, and the density between the discrete points is interpolated. As a result, a gradation / density characteristic that associates the relationship between the input gradation of the film imager 30 and the output density of the film is generated (S3).
[0021]
As shown in FIG. 7, the gamma correction is performed so that the gradation / luminance characteristics assumed linearly by the initial gamma correction match or approximate the gradation / density characteristics of the generated film. The characteristics are modified (S4).
[0022]
Next, the same test pattern data supplied to the film imager 30 stored in the test pattern data storage unit 13 of the monitor brightness adjustment device 10 is read out under the control of the system controller 11, and this time, the monitor brightness adjustment target Is supplied to the image generation device 20 or the image observation device 50 (S5). In the image generation device 20 or the image observation device 50, the gradation conversion unit 24 or 54, 56 converts the gradation of the test pattern data according to the gamma correction characteristic corrected in S4 (S6), and the monitor 25, 55, or 57. Shows the test pattern.
[0023]
Then, as shown in FIG. 4, the luminance at a plurality of discrete locations on the monitor on which the test pattern is displayed is detected by the luminance sensor 16 (S7). Next, in the gradation / luminance generating unit 17, as shown in FIG. 8, the luminance of the discrete points detected by the luminance sensor 16 is associated with the input gradation of the test pattern data, and the luminance between the discrete points is interpolated. As a result, a gradation / luminance characteristic that associates the current output luminance of the monitor 25, 55, or 57 with the input gradation to the image generation device 20 or the image observation device 50 to be adjusted in monitor luminance is generated (S8). .
[0024]
In the characteristic difference calculation unit 19, the difference between the actual gradation / luminance characteristics with respect to the gradation / density characteristics of the film is calculated for each input gradation (S9), and the difference is compared with a predetermined threshold value TH (S9). S10) When the difference is lower than the threshold value TH for all input gradations, the monitor luminance adjustment processing ends. When an input tone whose difference indicates the threshold value TH or more remains, the gamma correction characteristic corresponding to the input tone is corrected again (S11), and the difference is lower than the threshold value TH for all input tone levels. Until the processing, steps S5 to S11 are looped.
[0025]
In this way, the monitor gradation conversion is performed so that the gradation / density characteristics of the film actually detected using the test pattern are similar to the gradation / luminance characteristics of the monitor actually detected using the same test pattern. By correcting and repeating the gamma correction characteristics, the gradation / luminance characteristics of the actual monitor can be made to match or approximate the gradation / density characteristics of the actual film. This makes it possible to perform image interpretation on the monitor in substantially the same environment as image interpretation on film.
[0026]
(Modification)
The present invention is not limited to the above-described embodiment, and can be implemented in various forms without departing from the spirit of the invention at the stage of implementation. Furthermore, the above-described embodiment includes various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed components. For example, some components may be deleted from all the components shown in the embodiment.
[0027]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the operation | work which adjusts the brightness | luminance of a monitor so that the brightness | luminance of a monitor changes approximately with the density change of a film can be facilitated.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a monitor brightness adjusting device according to an embodiment of the present invention.
FIG. 2 is a diagram showing an example of test pattern data stored in a test pattern data storage unit of FIG.
FIG. 3 is a diagram showing an example of a place where a film density is detected in the density sensor of FIG. 1;
FIG. 4 is a diagram showing an example of a place where monitor luminance is detected in the luminance sensor of FIG. 1;
FIG. 5 is a flowchart showing a procedure of a monitor brightness adjusting method according to the embodiment of the present invention.
FIG. 6 is a view showing an example of a gradation / density characteristic generated in step S3 of FIG. 2;
FIG. 7 is a view showing an example of a gamma correction characteristic corrected in step S4 of FIG. 2;
FIG. 8 is a diagram showing an example of a deviation of a gradation / luminance characteristic from a gradation / density characteristic in step S9 of FIG. 2;
[Explanation of symbols]
10 monitor brightness adjustment device
11 ... System controller,
12 ... I / O interface,
13. Test pattern data storage unit
14: concentration sensor,
15: gradation / density generation unit
16 luminance sensor,
17 ... gradation / luminance generation unit
18: Gamma correction characteristic correction unit,
19 ... Characteristic difference calculator.

Claims (7)

Detects changes in the density of the film on which the test pattern is printed,
Detecting a change in brightness of the monitor on which the test pattern is displayed,
A monitor luminance adjustment method, comprising: correcting a gradation / luminance conversion characteristic of the monitor such that the detected luminance change matches or approximates the detected density change. Detects the density of the film on which the test pattern is printed at multiple locations,
Generating tone / density characteristics based on the detected densities at a plurality of locations;
Detecting the brightness of the monitor on which the test pattern is displayed at a plurality of locations,
A tone / luminance characteristic is generated based on the detected luminance at a plurality of locations,
A monitor luminance adjustment method, comprising: correcting a gradation / luminance conversion characteristic of the monitor based on a deviation of the generated gradation / luminance characteristic from the generated gradation / density characteristic. Detects the density of the film on which the test pattern is printed according to the test pattern data at multiple locations,
Generating tone / density characteristics based on the detected densities at a plurality of locations;
Correcting the gradation / luminance conversion characteristics of the monitor based on the generated gradation / density characteristics;
Detecting the luminance of the monitor on which the test pattern is displayed according to the test pattern data subjected to gradation conversion by the corrected gradation / luminance conversion characteristic at a plurality of locations,
A tone / luminance characteristic is generated based on the detected luminance at a plurality of locations,
A monitor brightness adjustment method, comprising: re-correcting a grayscale / brightness conversion characteristic of the monitor based on a deviation of the generated grayscale / luminance characteristics from the generated grayscale / density characteristics. A density sensor for detecting a density change of the film on which the test pattern is printed,
A brightness sensor for detecting a change in brightness of the monitor on which the test pattern is displayed,
A monitor brightness adjustment device, comprising: a correction unit that corrects the gradation-luminance conversion characteristic of the monitor so that the detected brightness change matches or approximates the detected density change. A density sensor for detecting the density of the film on which the test pattern is printed at a plurality of locations,
A gradation / density characteristic generation unit that generates a gradation / density characteristic based on the detected densities at a plurality of locations;
A brightness sensor for detecting the brightness of the monitor on which the test pattern is displayed at a plurality of locations,
A gradation / luminance characteristic generation unit that generates a gradation / luminance characteristic based on the detected luminance at the plurality of locations;
A monitor luminance adjustment unit that corrects the gradation / luminance conversion characteristic of the monitor based on a deviation of the generated gradation / luminance characteristic from the generated gradation / density characteristic. apparatus. A density sensor that detects the density of the film on which the test pattern is printed according to the test pattern data at a plurality of locations;
A gradation / density characteristic generation unit that generates a gradation / density characteristic based on the detected densities at a plurality of locations;
A correction unit that corrects a gradation / luminance conversion characteristic of a monitor based on the generated gradation / density characteristic;
A luminance sensor that detects the luminance of a monitor on which a test pattern is displayed in accordance with test pattern data that has been subjected to gradation conversion by the corrected gradation / luminance conversion characteristic at a plurality of locations;
A gradation / luminance characteristic generation unit that generates a gradation / luminance characteristic based on the detected luminance at the plurality of locations;
Calculating a difference between the generated gradation / luminance characteristics with respect to the generated gradation / density characteristics, and causing the correction unit to re-correct the gradation / luminance conversion characteristics of the monitor based on the calculated differences; And a monitor brightness adjusting device. An input unit for inputting image data,
A gradation conversion unit that performs gradation conversion of the image data according to a gradation-luminance conversion characteristic;
A monitor that displays the gradation-converted image data;
In an image observation device having a monitor luminance adjustment unit that corrects the gradation luminance conversion characteristic,
The monitor brightness adjustment unit,
A density sensor for detecting a density change of the film on which the test pattern is printed,
A brightness sensor for detecting a change in brightness of the monitor on which the test pattern is displayed,
An image observation apparatus, comprising: a correction unit that corrects the gradation-luminance conversion characteristic so that the detected luminance change matches or approximates the detected density change.

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