JP2753026B2 - Visualization of time-varying area - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Overview] Regarding a visualization method using real-time moving image processing, an image data to be displayed at regular time intervals is intended to display a change region of an image that changes over time so that it can be easily seen by a human. Input means for outputting image data from the image input means, reference image storage means for storing image data before time change among image data from the image input means as a reference image, image data from the image input means and the reference image storage means Calculate with image data from
Time-varying-region extracting means for extracting a region changed from the reference image data in the input image data, and a gradation for performing gradation conversion on the image data in the time-varying region from the time-varying region extracting means Conversion means, output gradation conversion image data of the gradation conversion means, input image data from the image input means, and data from the time change area extraction means are supplied, respectively, Combining means for replacing the gradation-converted image data with a part of the time-varying region of the input image data based on the data, and image display means for displaying the combined image data obtained by combining by the combining means And the configuration.

[Industrial applications]

The present invention relates to a method for visualizing a time-varying region, and more particularly to a visualizing method for realizing a time-varying region with human eyes by real-time moving image processing.

One of digital image processing using an electronic computer is a process for visualizing a time-varying region by real-time moving image processing. Here, the moving image processing refers to detecting a moving area, a moving amount, a speed, and the like, based on temporally changed information obtained between images acquired at different times,
The purpose is to distinguish moving areas with different speeds. In addition, real-time image processing is a process for continuously inputting image sequences at certain time intervals without stopping the flow.
Moving image processing, for which each processing must be performed within a time interval at which an image is input.

In such real-time moving image processing, it is important to display a time-varying area as easily as possible for humans.

[Conventional technology]

As a method of visualizing a time-varying region by moving image processing, there is a method of enhancing the change process of a diseased part by a contrast agent by a color modulation means (Japanese Patent Application No. 61-224933).
issue).

Further, as another technique related to visualization of a time-change area, conventionally, an improvement has been made to improve the time-change area so that the observation target can be easily seen by human eyes.
For example, in order to reduce the aerodynamic drag of a car, models of various shapes of the car body were created, the models were installed in the wind tunnel,
There is an experiment in which smoke is sprayed on the wind and swirling around the vehicle body to observe a position where the resistance is large. When the width of the smoke is wide, the state of the vortex cannot be seen. Therefore, efforts have been made to make the vortex easier to see by making the smoke thinner or coloring the smoke.

[Problems to be solved by the invention]

However, in the above-mentioned observation experiment of the aerodynamic resistance of automobiles, even if the smoke is squeezed thinly, the smoke may diffuse and become invisible because there is resistance, and multiple smokes with different colors are squeezed thinly and separately. However, when the light is emitted in the direction of the car at the same time, these smokes are mixed and individual smoke cannot be distinguished. This is because information for determining the presence or absence of smoke and for distinguishing colors cannot be captured by human eyes.

Further, the apparatus using the above-mentioned color modulation means merely displays only the position where the contrast agent exists, and cannot display the density difference or the like.

The present invention has been made in view of the above points, and an object of the present invention is to provide a visualization method of a time-varying region that can display a changing region of a temporally-varying image in a manner that is easy for a human to see.

[Means for solving the problem]

FIG. 1 is a block diagram showing the principle of a method for visualizing a time-varying region according to the present invention. In the figure, reference numeral 11 denotes an image input means for outputting image data to be displayed at regular time intervals. Reference numeral 12 denotes reference image input means for storing data relating to the image before the time change as reference image data.

Reference numeral 13 denotes a time-varying region extracting means for extracting a time-varying region that has changed from the reference image data in the input image data. 14
Is a gradation conversion means for performing gradation conversion on the image data in the time change region to obtain gradation converted image data.

Numeral 15 denotes a synthesizing means, which synthesizes the input image data by replacing the gradation-converted image data with the time-varying region. 16
Is an image display means for displaying synthesized image data obtained by synthesis by the synthesis means 15.

[Action]

The input image data obtained by the image input means 11 is taken out at regular time intervals and supplied to the reference image storage means 12, the time-change area extracting means 13 and the synthesizing means 15 described later. Here, the reference image storage means 12 stores the input image data before the time change as reference image data at a timing instructed by the user via the control means. Therefore, the reference image is a still image.

After that, the time-change area extracting unit 13 extracts a portion that has changed from the reference image data on the input image data, that is, a time-change area. The image data in the time-varying region is supplied to the gradation conversion means 14, where predetermined gradation conversion is performed, and the image data becomes image data which is easy for human eyes to see. Also,
This gradation conversion is a conversion that expands the dynamic range of the extracted time-varying region when the image display means 16 performs monochrome display, and is a conversion of the image data of the extracted time-varying region in the case of color display. This is a conversion for performing a pseudo color process of the hue set for each gradation region.

When the combined image data extracted from the combining unit 15 is displayed by the image display unit 16, a combined image including a real-time moving image in a time-varying region and a reference image (still image) in a time-invariant region is displayed.

Therefore, the moving image in the time-change area is displayed in a manner that is easy to see for human eyes by gradation conversion.

Embodiment FIG. 2 is a block diagram showing an embodiment of the present invention.

In the figure, the same components as those of FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In FIG. 2, control means for controlling each means and its control signal lines are omitted. It is also assumed that the image data includes a synchronization signal.

Each unit configured to simultaneously input a plurality of images requires an image signal delay unit for adjusting the timing deviation of the input image signals, but is not shown.

In FIG. 2, the image input means 11 includes, for example, a television camera and an A / D converter for A / D converting an output image signal of the television camera to obtain image data.

The image data from the image input means 11 is a data line a
Reference image storage means (which is generally constituted by a random access memory) via
And the difference image calculation means 21. Here, when the present embodiment is applied to the above-described experiment for observing the aerodynamic resistance of the vehicle, the reference image stored in the reference image storage means 12 is the vehicle before the smoke is blown as shown in FIG. 4A. 41
It is just an image. The storage of the reference image A is performed by an experimenter using input means.

Next, an experiment is started by spraying smoke on the above-mentioned automobile. Accordingly, at this time, the input image data obtained by the image input means 11 shows an image showing a state where the smoke 42 is being blown on the automobile 41 as shown in FIG. 4B. Instead of being stored in the image storage means 12, the difference image data is supplied to the difference image calculation means 21, where the difference from the reference image A input from the reference image storage means 12 via the data line b is obtained.

Here, the difference image calculation means 21 is configured as shown in FIG. 3, for example, and temporarily stores input image data having 8 bits of quantization bits and reference image data in the resists 31 and 32, and then performs arithmetic operation. Logical operation unit (ALU) 33
, The subtraction of the input image data and the reference image data is performed, and the obtained difference image data is temporarily stored in the register 34.

Since the difference image data becomes only the image data of the moving image in which the image information continuously changes in time by canceling out the reference image data in the input image data, the image is shown in FIG. A moving image of the smoke 42 is obtained as shown in FIG.

This difference image data is compared with a preset threshold value by the threshold value processing means 22 shown in FIG. 2, and the image data of the time-varying region where the moving image exists in the region of one screen is, for example, "1". The image data of the natural change area / time non-change area is converted into data of a value of “0”, that is, data that distinguishes the time change area from the natural change area / non-change area, and output to the data line d.

Further, the above-mentioned difference image data is supplied to the pseudo color processing means 23 constituting the gradation conversion means 14 via the data line c shown in FIG. 2, where it is assigned to each predetermined gradation range. Is converted into image data of a predetermined hue. That is, for the sake of simplicity, assuming that the difference image data is 8 bits and has 256 gradations, for example, the difference image data is divided into 16 in units of 16 gradations, and one color is applied to the image data in each divided gradation range. Assign 16 colors each. Alternatively, this is performed by cyclically assigning three primary colors.

As a result, as shown in FIG. 4D, the image based on the gradation-converted image data extracted to the data line e by the pseudo color processing means 23 has, for example, different hues according to the gradation of the white smoke 42, that is, the luminance. Is a pseudo color image of the five smoke portions 43 to 47. The pseudo color image of the smoke portions 43 to 47 may be a repetition of three primary colors.

The threshold processing unit 22 and the pseudo color processing unit 23 are realized by, for example, processing by software of an electronic computer.

The above-mentioned gradation-converted image data and the input image data input via the data line a are respectively supplied to the synthesizing means 13 shown in FIG. 2 and change over time based on the data input via the data line d. The pseudo color image data is selectively output to the area determined as the area, and the input image data is selectively output to the area determined as the natural change area / non-change area.

Therefore, as shown in FIG. 4E, the image based on the image data output from the synthesizing means 15 to the data line f is the input image B.
In the area determined to be the time-varying area,
The 47 pseudo-color images are replaced composite images.
This composite image E is displayed by image display means 16 such as a cathode ray tube (CRT).

Therefore, according to the present embodiment, since the moving image of smoke in the time-varying region, which cannot be normally caught by the human eye, is displayed as a pseudo-color image, it can be easily identified by the human eye, and furthermore, according to the luminance. Therefore, it is possible to easily identify the luminance difference.

The present invention is not limited to the above embodiment. For example, instead of the ALU 33 shown in FIG. 3, a memory in which subtraction results are stored in advance as a table may be used (in that case, The input image data and the reference image data are input as addresses.) Threshold processing means 22,
The pseudo-color processing means 23 can be realized by a similar configuration.

Further, the gradation conversion means 14 is the pseudo color processing means described above.
Other than 23, any of equal frequency conversion means, logarithmic conversion means, exponential conversion means, and sawtooth conversion means are possible. Here, assuming that the total number of gradations is N, the equal frequency conversion means makes the number of pixels having each gradation as a pixel value equal, thereby converting the image data so that the average gradation becomes N / 2. It is a means to convert. The logarithmic conversion means is a means for performing gradation conversion according to a logarithmic distribution, and is effective in the case of a bright image with a bright background because the difference between the background and the image (multiple objects) becomes large. On the other hand, the exponential conversion means is means for performing gradation conversion according to the exponential distribution, and is effective for a dark image with a dark background. Further, the sawtooth conversion means is a means for performing a gradation conversion such that a portion having the same gradation looks bright in a certain cycle.

〔The invention's effect〕

As described above, according to the present invention, it is possible to display a change area of an image that changes over time in a manner that is easy for a human to see, and it is also possible to clearly display a difference in luminance of a real-time moving image. Have

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of the principle of the system of the present invention, FIG. 2 is a block diagram of one embodiment of the present invention, and FIG. FIG. 4 is a diagram for explaining the operation of each unit in FIG. In the figure, 11 is an image input means, 12 is a reference image storage means, 13 is a time-varying region extraction means, 14 is a gradation conversion means, 15 is a synthesis means, 16
Denotes image display means, 21 denotes difference image calculation means, 22 denotes threshold processing means, and 23 denotes pseudo color processing means.

Claims (1)

(57) [Claims] An image input means (11) for outputting image data to be displayed at regular time intervals, and image data before time change among image data from the image input means (11) is stored as a reference image. A reference image storage means (12) for performing the operation of the image data from the image input means (11) and the image data from the reference image storage means (12); Time change region extracting means (13) for extracting a region changed from the image data; and gradation conversion means (14) for performing gradation conversion on image data in the time change region from the time change region extraction means (13). ), The output gradation-converted image data of the gradation conversion means (15), the input image data from the image input means (11), and the data from the time-varying region extraction means (13) are supplied, respectively.
Based on the data from the time-varying region extracting means (13),
A synthesizing means (15) for replacing the gradation-converted image data with a part of the time-varying region of the input image data and synthesizing the image, and an image for displaying the synthesized image data obtained by synthesizing by the synthesizing means (15) A method for visualizing a time-varying region, comprising a display means (16).