JPH03249693A - Contrast setting device for image display device - Google Patents

Abstract

PURPOSE:To improve operability by changing the central value or the density width of a density area which becomes an object of processing for emphasizing contrast based on the larger quantity of the rotational displacement out of the rotational displacement quantity in an orthogonal two axes direction in the case that a track ball is operated to be rotated. CONSTITUTION:Rotary encoders 2X and 2Y are respectively connected to follower rollers 1X and 1Y for extracting the rotation of the track ball TB in an X direction and a Y direction, and pulse signals SX and SY corresponding to the rotation are outputted. The rotational amount of the track ball TB is detected by counting respective pulse signals by up-down counters 3x and 3Y. The width W of the density area which is the object of the emphasizing processing and the central value M thereof are outputted as the contrast set conditions by a microcomputer 4 based on numerical values NX, NY, and the processing for emphasizing the contrast in an original image is performed by an image processing circuit 5 based on the set contrast conditions. Thus, the operability can be improved without changing a window set value even in the case that the deviation of the track ball in the rotating direction occurs.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of Application The present invention is used in image display devices such as X-ray tomography devices and nuclear magnetic resonance tomography devices, and is particularly suitable for setting the contrast of digital images. Regarding equipment.

B. Prior Art Conventionally, this type of image display device has a density range (hereinafter referred to as a window) that is the target of enhancement processing in order to enhance the contrast of a digital image of a region of interest and make the image easier to see. The center value and its value.

One is equipped with operation buttons for setting the center value of the window and operation buttons for setting the window width.The operator sets the desired window by operating each operation button. It is now possible to do so.

However, according to this method using operation buttons,
In order to set the window, the operator has to operate two operation buttons, which is cumbersome.

Therefore, in order to eliminate this inconvenience, an operating means using a so-called trunk ball that can set the center value and width of the window has been proposed and implemented. When an operator rotates a sphere whose upper part is exposed on a surface in an arbitrary direction, a rotation amount detection means attached to the sphere detects the amount of rotational operation as displacement amount components in the X and two orthogonal axes directions. This is what is output as.

Conventionally, in a window setting operation means using this type of trackball, when the trackball is rotated in the X direction, the window width changes according to the amount of rotational displacement in the X direction, and the trunk ball changes. When a rotational operation is performed in the X direction, the center value of the window changes according to the amount of rotational displacement in the X direction.

In the second case, it is difficult for the operator to accurately rotate the trunk ball in the X direction or in the X direction, and some deviation occurs in the rotation direction. It would be inconvenient if one of the window setting values changed unexpectedly due to such a slight deviation in the direction of rotation operation, so in conventional devices, a sensing band and a dead band are set as shown in Figure 5. There is. FIG. 5 is a plan view of the trackball TB, and when the trackball TB is rotated within the range of the sensing band indicated by area A in the figure, the amount of rotational displacement in the X direction is ignored;
The center value of the window is changed based on the amount of rotational displacement in the X direction, and similarly, when the trackball TB is rotated within the range of the sensing band indicated by the circular 8 nod area, the amount of rotational displacement in the X direction is changed. The width of the window is converted based on the amount of rotational displacement in the X direction, ignoring this. and the sensing band A,
A dead zone C is set between B, and when the trackball TB is operated within this dead zone C, X, Y
Any amount of rotational displacement is ignored and the window setting value is not changed.

C1 Problems to be Solved by the Invention However, the above-mentioned conventional device has the following problems.

That is, rotating the trackball TB so as to fall within the sensing band A or B as described above is not necessarily acceptable, and may fall within the sensing band C. In particular, when the trackball TB is slightly displaced or when the movement of the trackball TB is not smooth, the rotational direction of the trackball TB often falls into the dead zone C against the operator's will. Therefore, even though the operator is operating the trackball TB, the window setting value does not change, which hinders the operability of the window setting.

This invention was made in view of the above circumstances, and when setting the windshield using a trackball, even if a deviation occurs in the direction of rotation of the trackball,
To provide a contrast setting device for an image display device with good operability, in which the window setting value corresponding to the direction of deviation does not change, and also eliminates the inconvenience that the window setting value does not change due to the above-mentioned infrared zone. It is an object.

01 Means for Solving the Problems The present invention has the following configuration to achieve the above object.

That is, the present invention provides a contrast setting device for an image display device in which the center value of a density range to be subjected to contrast enhancement processing and its density width are set by operating a trackball. A comparison that compares the magnitude of the rotational displacement amount in the orthogonal two axes directions based on a rotation amount detection means that detects the rotation amount in each of the two orthogonal axes directions and the rotation amount in each direction given from the rotation amount detection means. and a large amount of rotational displacement in the axial direction detected by the comparing means,
a contrast condition setting means for changing the center value or the density width of the density range to be subjected to the enhancement processing according to the axial direction; It is equipped with an image processing means that performs emphasis processing.

E0 Effect According to the present invention, when the trackball is rotated, the rotation amount detection means detects the amount of rotation of the trackball in two orthogonal axes directions, and provides the rotation amounts to the comparison means. The comparison means compares the amount of rotational displacement in each direction based on the amount of rotation in two orthogonal axes directions. The contrast condition setting means is an image processing means that changes the contrast condition (i.e., the center value of the density range targeted for enhancement processing or the density width thereof) corresponding to the larger amount of rotational displacement determined by the comparison means. performs contrast enhancement processing on the original image based on the contrast conditions set by the contrast condition setting means.

F. Example Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a contrast setting device in an image display device according to an embodiment of the present invention.

Rotation and IX ly are driven rollers that extract the rotation of the trackball TB in the X direction and the Y direction.
Well, 2Y is connected. Low reencoder 2X,
2- outputs pulse signals SX and Sv corresponding to the rotation of the trackball TB in the X and Y directions. Up/down counter 3X.

3v detects the amount of rotation of the trackball TB in the XY force directions by counting the pulse signals S, SY, respectively. The above-mentioned rotary encoder 2. ．． 2y and up/down counter 3x.

37 and the like correspond to the rotation amount detection means in this invention.

Up/down counter 3-. Count 4fL obtained at 3v
Nx and Nv are given to the microcomputer 4.

The microcomputer 4 has the functions of comparison means and contrast condition setting means in the present invention. The specific functions of this microcomputer 4 are as follows:
This will be made clear in the operation description below. Based on the count values Nx and Ny, the microcomputer 4 outputs the width W of the density region to be emphasized and its center value M to the image processing circuit 5 as contrast setting conditions.

The image processing circuit 5 performs contrast enhancement processing on the original image stored in the image memory 6 according to the contrast conditions given by the microcomputer 4, and provides the result to the display memory 8 via the lookup table 7. . The lookup table 7 is composed of a plurality of memories for correcting the gradation of the image signal that has been subjected to contrast enhancement processing by the image processing circuit 5. By giving the input image signal as an address designation signal for each memory, the data set in advance at each address is
It is output as a tone-corrected image signal. The operator can specify any memory in the lookup table 7 to make the desired tone correction.

The image signal stored in the display memory 8 is applied to the CRT 9, whereby an image subjected to contrast enhancement processing and gradation correction is displayed on the CRT 9.

Next, the contrast setting operation in the above-mentioned apparatus will be explained with reference to FIG.

FIG. 2 is a flowchart showing the sequence of operations for setting Okel contrast in the microcomputer 4.

The microcomputer 4 has an up/down counter 3.
．． It monitors whether or not the trackball TB has been rotated by taking in the counted values NX and Ny of 3Y at regular intervals and determining whether or not there are any changes.
Step Sl). When the trackball TB is rotated, the amount of rotational displacement ΔNX in the X and Y directions is determined by taking the difference between the previously captured count values N,, N,' and the currently captured count values Nx, NY. (Nl=NX
), ΔN months (NY - NY) are calculated (step S2). Then, the amount of rotational displacement in two directions ΔN, ΔN.

If the amount of rotational displacement ΔN in the X direction is larger, the process proceeds to step S4.
The window width W is changed by a value corresponding to the rotational displacement amount ΔN. On the other hand, if the rotational displacement amount ΔNV in the X direction is larger, the process proceeds to step S5, and the window center value M is changed by a value corresponding to the rotational displacement amount ΔN7.

By performing the above processing in the microcomputer 4, the trackball TB can be
If rotational operation is performed in the area of sensing band A including the Y axis,
Depending on the amount of rotational displacement in the X direction, only the window center value M changes, and if the rotational operation is performed in the area of the sensing band B that includes the X axis, depending on the amount of rotational displacement in the X direction,
Only the window width W changes. As is clear from FIG. 3, unlike the conventional device shown in FIG. 5, there is no dead zone between the sensing bands A and B, so if the operator rotates the trackball TB, the The window setting value corresponding to the axial direction close to the rotation direction always changes.

The window setting values W and M output from the microcomputer 4 are given to the image processing circuit 5.

Based on these setting values W and M, the image processing circuit 5
For example, contrast enhancement processing is performed based on the following arithmetic expression.The following expression is an example of displaying an original image with 256 gradations.

1=(256/W) ・(10-M) +1270
≦■≦255 In the above equation, ■ is the image density level after contrast enhancement processing, and Io is the density level of the original image (in this example, each pixel is expressed in 16-bit gradation). (
Among the original images shown in a), the density level is 750.
When trying to highlight the density range between 1250 and 1250,
Rotate the trunk ball TB to determine the center value M of the wind.
is set to 1000, and the window width W is set to 500. Such window setting values are displayed on the CRT 9 etc. as appropriate according to instructions from the microcomputer 4.
The operator displays the current window settings on i! can be approved. Images obtained by emphasizing the original image based on the window settings set in this way are shown in FIGS.

In addition, in the above-mentioned embodiment, the row encoders 2x, 2
The up/down counter 3-
．． 3v, the microcomputer 4 may be used instead.

G0 Effects of the Invention As is clear from the above description, according to the present invention, when the trackball is rotated, based on the larger rotational displacement amount of the rotational displacement amounts in the two orthogonal axes directions,
Since the center value or density width of the density range targeted for contrast enhancement processing is changed, if the trackball is not rotated accurately in two orthogonal axes directions, contrast conditions corresponding to the direction of deviation are required. Furthermore, since there is no dead band in the rotational direction of the trackball, there is no inconvenience that the contrast condition does not change even though the trackball is being rotated, making it possible to use an easy-to-operate contrast setting device. It can be realized.

[Brief explanation of drawings]

1 to 4 are explanatory views of one embodiment of the present invention, the first view is a block diagram showing the schematic configuration of the contrast setting device, the second view is an operation flowchart, and the third view is a track diagram. FIG. 4 is an explanatory diagram of the ball sensing band, and FIG. 4 is an explanatory diagram of contrast enhancement processing. FIG. 5 is an explanatory diagram of the sensitive zone and the sensitive zone of the trackball in the conventional device. TB...Trackball 2, 2-...Rotary encoder 3x, 3V...Up/down counter 4...Microcomputer 5...Image processing circuit

Claims (1)

[Claims] (1) In a contrast setting device for an image display device, in which the center value of a density region to be subjected to contrast enhancement processing and its density width are set by operating a trackball, the orthogonal two
rotation amount detection means for respectively detecting the amount of rotation in the axial direction;
a comparing means for comparing the magnitude of rotational displacement in the two orthogonal axes directions based on the amount of rotation in each direction given by the rotation amount detecting means; a contrast condition setting means for changing the center value or the density width of the density range to be subjected to the enhancement processing according to the axial direction based on the amount of rotational displacement; and a setting given by the contrast condition setting means. 1. A contrast setting device for an image display device, comprising an image processing unit that performs contrast enhancement processing on an original image based on the contrast value.