JPH04270474A - Gradation controller by attention areas - Google Patents

Abstract

PURPOSE:To make contrast strong up to a maximum enabling display for each attention area by providing an attention area setting device and plural gradation conversion tables. CONSTITUTION:In respect to the gradation controller composed of gradation conversion tables 3A-3C to convert the value of an image memory 1 for storing image data to the value of a display memory, gradation conversion table converter 4 to change and control the gradation conversion tables 3A-3C, and CRT display 6 to display an image stored in the display memory 5 for storing the outputs of the gradation conversion tables 3A-3C, this gradation controller by attention areas is equipped with an attention area setting device 2 to extract the attention area in the image memory 1 and the gradation conversion tables 3A-3C to enable conversion corresponding to the respective attention areas.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tone control device for each region of interest, and more particularly to a tone control device for each region of interest for medical images such as X-ray films and CT images.

0002

2. Description of the Related Art A conventional gradation control device, as shown in FIG. It consisted of a gradation table converter for changing tables, a display memory, and a CRT for display.

0003

[Problems to be Solved by the Invention] The above-mentioned conventional gradation control device has one conversion table, and the effective data range of the image memory is 4 to 4 times the effective data range of the display memory.
Due to its 16x magnification, it is not possible to maximize the contrast of both whitish and dark areas at the same time when handling chest films that have a wide data range from white to black in one image. was there. Figure 3
is an example of a gradation table that maximizes the contrast of the near-black parts of the image memory, and as Figure 4 is displayed using that gradation table, all the near-white parts become pure white. This is an example of an image. Also, Figure 5 is an example of a gradation table that maximizes the contrast of areas close to white.
FIG. 6 is an example of an image in which all near-black parts are completely black because the image is displayed using the gradation table.

0004

[Means for Solving the Problems] A gradation control device for each region of interest of the present invention includes an image memory for storing image data, a gradation conversion table for converting values in the image memory to values in a display memory, and It consists of a gradation table converter that changes and controls a gradation conversion table, a display memory that stores the output of the gradation conversion table, a CRT display that displays the image stored in the display memory, and an image memory. The device includes a region of interest setting device for extracting a region of interest in the region of interest, and a gradation conversion table that corresponds to each region of interest and can be changed independently.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be explained with reference to the drawings.

The region-of-interest gradation control device of the present invention is a region-of-interest control device for extracting regions of interest from an image, with the aim of maximizing the contrast between dark and whitish parts of the image. It has a setting device and a plurality of conversion tables that can be changed independently corresponding to each region of interest.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention, and FIG. 5 shows the situation when the contrast is maximized for each block according to the present invention.
1 is an example of a gradation table, and part (b) is a display diagram showing an outline of a displayed image. The data in the image memory 1 is divided into a plurality of blocks 2A to 2C by the region of interest setting device 2, and tone conversion tables 3A to 2C are applied to the blocks.
3C corresponds to each of the plurality of divided blocks, and is independently converted by the gradation table converter 4. The converted data is superimposed on the display memory 5, and CR
It is displayed as one image on the T display 6.

In FIG. 5, the diagram (a) shows an example of a gradation table for each block, and the diagram (b) shows an outline of the displayed image. They correspond to the gradation tables 20A to 20C for each block, respectively. Therefore, the image is divided into several areas and the gradation conversion tables 3A to 3C of each image are controlled by the gradation table converter 4 to create the display memory 5, and the CRT display 6
will be displayed.

[0009]

As explained above, the present invention has a region of interest setting device and a plurality of gradation conversion tables, so that the region of interest can be set by dividing the image stored in the image memory into several parts. However, since the image is converted by searching for a gradation conversion table that obtains the maximum contrast for each divided area, it has the effect of increasing the contrast to the maximum that can be displayed for each area of interest.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

[FIG. 2] A block diagram showing the configuration of a gradation control device for each region of interest according to the conventional technology.

[Fig. 3] Shows the situation when the contrast of dark areas is maximized using the conventional technology. Diagram (a) shows the gradation conversion table, and diagram (b) shows the outline of the displayed image. figure

[Figure 4] Shows the situation when the contrast of a whitish area is maximized using the conventional technology. Diagram (a) shows the gradation conversion table, and diagram (b) shows the outline of the displayed image. figure

FIG. 5 shows the situation when the contrast is maximized for each block according to the present invention, with diagram (a) showing an example of a gradation table and diagram (b) showing an outline of the displayed image. figure.

[Description of symbols] 1.11 Image memory 2.12 Region of interest setting device 3A to 3C.12 Gradation conversion table 4
Gradation table converter 5/13 Display memory 6/14 CRT display 20A-20C Gradation conversion table 21A-21
B Image memory

Claims (1)

[Claims] [Claim 1] An image memory for storing image data;
a gradation conversion table that converts values in the image memory to values in a display memory; a gradation table converter that changes and controls the gradation conversion table; a display memory that stores the output of the gradation conversion table; It consists of a CRT display that displays images stored in a display memory, a region of interest setting device that extracts a region of interest in the image memory, and a gradation conversion table that corresponds to each region of interest and can be changed independently. A gradation control device for each region of interest, comprising: