JP2001060087A - Method and device for picture display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To display a picture with optimum luminance for every picture display means in a method in which a picture display means displays picture based on picture signals that are picture-processed. SOLUTION: In the picture display method, a picture processing means 11 picture-processes picture signals S based on a specific picture processing condition d that is related to the signals S and a picture display means 12 displays the picture based on the processed picture signals S'. By changing the condition d, the means 12 displays a picture with desired luminance and the difference between the changed picture processing condition and the condition d is stored in a storage means 13. When the means 12 displays a picture, a picture processing is conducted in accordance with the picture processing condition which is provided by uniformly adding the difference read from the means 13 to the condition d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for displaying an image on an image display means based on an image signal subjected to image processing, and more particularly, to a method for displaying an image with optimum luminance for each image display means. It relates to an image display method.

[0002] The present invention also relates to an apparatus for implementing the above-described image display method.

[0003]

2. Description of the Related Art Conventionally, when an image is displayed by an image display means such as a CRT or a liquid crystal display, a gradation characteristic (a relationship between an image signal value and a logarithmic value such as luminance on the image display means) is required. ) Is prepared, and an image is displayed after image processing is performed on an image signal in accordance with the gradation conversion table.

When displaying a medical image such as a transmitted radiation image of a human body on the CRT or the like, generally, image processing conditions considered to be optimal for each radiographing menu on the side of a radiographic image capturing apparatus or an image acquiring apparatus such as an MRI. Is set, and the image processing conditions are attached to the image signal and sent to the image display device side, and the image processing is performed according to the image processing conditions. In other words, if the shooting menu is a common image, image processing is performed under the same conditions in any image display means.

Since the above-mentioned gradation characteristics are usually calibrated to a predetermined characteristic, if image display means having the same luminance characteristics are used, as long as the photographing menu is common,
All images are displayed with the same brightness and the same gradation.

[0006]

However, some users who observe the image on the image display means feel dazzling at the luminance which is considered to be appropriate, or some people feel dark at the contrary. .

In order to solve this problem, it is conceivable to change the image processing conditions for each photographing menu attached to the image signal at the time of photographing according to the user. In such a case, however, which user observes each image is considered. Must be managed from the time of photographing, and it takes a lot of time and is difficult to actually perform.

In order to solve the above-mentioned problem, it is conceivable to use a preset image processing function which can be set for each image display means. This preset image processing function allows a plurality of combinations of image processing conditions to be set in advance for each image display means so that one of the combinations of the plurality of image processing conditions can be selected and applied. It was done. However, this preset image processing function
Originally, an image once displayed is reprocessed under different conditions for each diagnostic purpose. To solve the above problem, it is necessary to reprocess the image every time the image is displayed, which is not practical.

Further, in order to solve the above problem, C
It is also conceivable to individually adjust the brightness of the image display means such as the RT. However, changing the luminance and contrast for each image display means is not preferable from the viewpoint of guaranteeing the image quality of the image display means.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in a method of displaying an image on an image display means based on an image signal subjected to image processing, it is possible to display an image with optimum luminance for each image display means. The purpose is to do.

Another object of the present invention is to provide an image display device capable of implementing the above-described image display method.

[0012]

According to an image display method of the present invention, an image signal is subjected to image processing in accordance with a designated image processing condition attached thereto, and the image display means applies the image signal to the image signal after the image processing. In the image display method for displaying an image based on the specified image processing condition, the specified image processing condition is changed, an image having a preferable luminance is displayed on the image display means, and the changed image processing condition is compared with the specified image processing condition. When the difference between the image data is stored in the storage means, and thereafter, the image is displayed on the image display means, the image processing condition obtained by uniformly adding the difference read from the storage means to the designated image processing condition attached to the image signal. The image processing is performed according to the following.

As the above-mentioned image processing condition, a condition for adjusting the overall luminance of the display image, for example, a condition for shifting the gradation conversion characteristic as a whole can be applied.

On the other hand, an image display device of the present invention for implementing the above-described image display method comprises: an image processing means for performing image processing on an image signal based on designated image processing conditions attached thereto; In an image display device comprising an image display unit for displaying an image based on a subsequent image signal, an image processing condition changing unit for changing the specified image processing condition, and an image having a preferable luminance in the image display unit. Storage means for storing a difference between the changed image processing condition when displayed and the specified image processing condition, wherein the image processing means includes a designated image processing Image processing is performed according to an image processing condition in which the difference read out from the storage unit is uniformly added to a condition.

[0015]

According to the image display method of the present invention, a designated image processing condition attached to an image signal is changed so that an image having a preferable luminance is displayed on an image display means. The difference between the image processing condition and the image processing condition is stored in the storage unit, and when the image is subsequently displayed, the image processing condition in which the difference read out from the storage unit is uniformly added to the designated image processing condition attached to the image signal Since the image processing is performed in accordance with the conditions, the brightness adjustment corresponding to the difference is automatically performed for each image display means, so that an image is always displayed at a preferable brightness for each image display means. It becomes possible.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an image display device according to one embodiment of the present invention. The apparatus includes an image processing condition reading unit 10, an image processing unit 11 for receiving an output from the image processing condition reading unit 10, an image display unit 12 including a CRT connected to the image processing unit 11, for example. It comprises an image processing condition storage unit 13 connected to the image processing unit 11 and an image processing condition changing unit 14 also connected to the image processing unit 11. The image processing condition reading unit 10, the image processing unit 11, the image processing condition storage unit 13, and the image processing condition changing unit 14 are configured by a computer system.

The image processing condition reading unit 10 receives a digital image signal S carrying a medical image, for example, a transmitted radiation image of a subject. This image signal S is described in, for example,
2429, 56-11395, 55-163472, 56-104645
No. 55-116340, etc., and are transferred from a radiation image recording and reading system using a stimulable phosphor sheet.

Here, the radiation image recording and reading system will be briefly described. Radiation (X-ray, α-ray, β-ray,
Irradiation with gamma rays, electron beams, ultraviolet rays, etc. accumulates a part of this radiation energy, and then irradiation with excitation light, such as visible light, causes a stimulable phosphor (luminous) to emit stimulated emission according to the accumulated energy. Phosphor) is known. In the above system, a radiation image of a subject such as a human body is once photographed and recorded on a sheet having a layer of a stimulable phosphor, and the stimulable phosphor sheet is scanned with excitation light such as laser light to generate stimulated emission light. The obtained stimulated emission light is photoelectrically read to obtain an image signal carrying a radiation image of the subject.

The above-mentioned image signal S is accompanied by image processing conditions d which are considered to be optimal for each photographing menu of a subject such as chest simple photographing and angiographic photographing. Such image processing conditions d include, for example, when a radiation image is read from the stimulable phosphor sheet, imaging menu information indicated using a barcode or the like on this sheet, or a reading device online from the imaging device. The photographing menu information sent to the user can be read and set and attached based on the read information.

Alternatively, predetermined image processing conditions are set in the radiographic image capturing apparatus in accordance with a radiographing menu, and information indicating the image processing conditions is attached to the stimulable phosphor sheet in the form of a bar code or the like. The information may be read, and the read image processing conditions may be added to the image signal.

The image signal S is subjected to image processing such as gradation processing and frequency emphasis processing based on the accompanying image processing condition d in the image processing means 11, and the image signal S 'after the image processing is performed.
Is input to the image display means 12 comprising a CRT as an example. The image display means 12 reproduces and displays the transmitted radiation image of the subject based on the image signal S '.

In the present embodiment, the conditions of the gradation processing among the above-mentioned image processing are changed appropriately for each image display means 12 so as to realize a preferable display luminance. Hereinafter, this point will be described in detail.

First, the gradation processing will be described. It is desired that the gradation characteristic (the relationship between the input signal value Q indicating the image density and the logarithmic value B) of the image display means 12 is linear.
The actual CRT gradation characteristics are as shown by a curve a in FIG. Then, the value (pixel value) D of the image signal S
Is converted into the input signal value Q by the characteristic of the curve b in the same figure, the relationship between the image signal value D and the logarithmic value B becomes linear as shown by the straight line c in the same figure. Further, by appropriately changing the gradation conversion curve b, it is possible to raise or lower the overall luminance level or change the contrast.
In this example, as parameters that define the gradation processing conditions,
Four parameters of “GA”, “GT”, “GC” and “GS” are included in the image processing condition d.

Here, GA indicates the degree of gradation enhancement, that is, gradation inclination, and GT indicates the type of gradation curve. G
C represents the center of rotation when changing the gradient of the gradation, and GS represents the shift amount of the gradation curve. Therefore, if the value of the parameter GS is changed, the display brightness of the image display means 12 will increase or decrease as a whole. Hereinafter, the operation of adjusting the display brightness as a whole will be described.

For example, when a certain radiation image is reproduced and displayed, the parameter attached to the image signal S is GA = 1.
0, GT = E (this indicates one type of gradation curve),
It is assumed that GC = 1.2 and GS = 0.0. Then, it is assumed that the user has determined that the overall luminance of the radiation image displayed based on the image signal S ′ subjected to the gradation processing under this condition is insufficient.

In this case, the value of GS is changed by operating the image processing condition changing means 14 composed of a mouse, a keyboard and the like. Here, when GS = -0.2, it is assumed that the user has determined that the overall luminance has increased to an appropriate level. This GS
The numerical value = −0.2 is a value that reduces the display density by 0.2 digits.

The difference ΔGS between the GS value after the change and the GS value originally attached to the image signal S is −0.2, and this value is stored in the image processing condition storage unit 13. Thereafter, the image signal S is sent to the image processing means 11 to display an image.
Each time the image processing condition d is input, the value of ΔGS = −0.2 stored in the image processing condition storage unit 13 is read out by the image processing unit 11 and is stored in the parameter GS included in the image processing condition d. On the other hand, a value of -0.2 is uniformly added.

The parameter G changed as described above
If gradation processing is performed using S, the image displayed on the image display means 12 based on the processed image signal S 'will be displayed with appropriate luminance as a whole.

In the embodiment described above, the value of the parameter GS is uniformly changed by -0.2. However, the change width is not limited to this value, and the brightness of the display image before the change may be changed. What is necessary is just to determine suitably. For example, when the brightness of the display image is too high and dazzling as a whole, the value of the parameter GS may be uniformly increased by 0.2, contrary to the above case.

The present invention is not limited to the image display means composed of a CRT, but can be applied to the case where other image display means composed of a liquid crystal display, DMD or the like is used, and has the same effect.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an image display device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram illustrating gradation processing.

[Explanation of symbols]

 10 Image processing condition reading unit 11 Image processing unit 12 Image display unit 13 Image processing condition storage unit 14 Image processing condition changing unit S Image signal d Image processing condition attached to image signal

Claims (6)

[Claims] 1. An image display method, comprising: performing image processing on an image signal according to designated image processing conditions attached thereto; and displaying an image based on the image signal after the image processing in an image display means. The designated image processing condition is changed, an image having a preferable luminance is displayed on the image display means, and a difference between the changed image processing condition and the designated image processing condition is stored in the storage means. When displaying an image on the image display means,
An image display method, comprising: performing image processing in accordance with image processing conditions obtained by uniformly adding the difference read from the storage means to designated image processing conditions attached to an image signal. 2. The image processing condition according to claim 1, wherein the image processing condition is a condition for adjusting the overall luminance of the display image.
Image display method described. 3. The image display method according to claim 2, wherein the image processing condition is a condition for shifting a gradation conversion characteristic as a whole. 4. An image processing means for performing image processing on an image signal based on a designated image processing condition attached thereto, and an image display means for displaying an image based on the image signal after the image processing. An image display device comprising: an image processing condition changing unit configured to change the specified image processing condition; and the changed image processing condition when an image is displayed at a preferable luminance on the image display unit; A storage unit for storing a difference between the image processing condition and the image processing condition, wherein the image processing unit uniformly adds the difference read from the storage unit to a designated image processing condition attached to an image signal. An image display device configured to perform image processing according to processing conditions. 5. The image processing condition according to claim 4, wherein the image processing condition is a condition for adjusting the overall luminance of the display image.
The image display device as described in the above. 6. The image display apparatus according to claim 5, wherein the image processing condition is a condition for shifting a gradation conversion characteristic as a whole.