JPH0571114B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a graph display method for time-series image data suitable for use in understanding temperature changes over time at any part of a measurement target, and particularly relates to This invention relates to a graph display method for time-series image data that allows for direct reading of how the temperature of any part changes over time from the start of measurement.

[Conventional technology]

FIGS. 5 and 6 are diagrams for explaining conventional display screens of thermography apparatuses.

A thermography device is known as a device that obtains a temperature distribution image of a measurement target. According to this thermography device, infrared rays emitted from an object to be measured are scanned and focused, detected by an infrared detector, and the obtained infrared image signal is sent to a display device directly or via an image memory, for example. A temperature distribution image Z is displayed as shown in FIG. In Figure 5, HC and VC are movable horizontal cursors, respectively.
This is a vertical cursor, and the temperature along the horizontal cursor HC is shown below the image Z as a waveform W _h , and the temperature along the vertical cursor VC is shown below the image Z as a waveform W _v .
Further, the temperature value at the intersection point CP of these two cursors is sampled, and the temperature value is displayed above the image Z as a numerical value. This statue Z
is rewritten every time the screen is scanned, for example once every second, so the cursor intersection
Temperature changes can be ascertained by monitoring the temperature value of CP.

If you want to actually record the change over time in the temperature value at this cursor intersection point CP,
It is conceivable to sequentially display temperature values numerically on the same screen as image Z, as proposed in Japanese Patent Application No. 57-186917. Furthermore, although the present inventor has previously proposed and filed a separate application, it is also an effective method to display temperature changes at arbitrary positions in the temperature distribution image as a graph as shown in FIG.

[Problem that the invention seeks to solve]

However, simply displaying the temperature at each measurement point numerically or graphically has the problem that it is not possible to directly read how the temperature at a certain point on the subject has changed since the beginning of the measurement. . This is because the starting point of the graph shown in FIG. 6 indicates the actual temperature value at the start of the measurement.

The present invention is based on the above invention, and includes:
It is an object of the present invention to provide a graph display method for time-series image data that allows one to directly read how the temperature at a certain point on a subject has changed since the start of measurement.

[Means for solving problems]

To this end, the time-series image data graph display method of the present invention reads out time-series pixel data values at a predetermined position from a memory that stores time-series image data, and calculates the first pixel data value from each of the time-series pixel data values. It is characterized by subtracting and displaying the values obtained by the subtraction as a graph, and further reading out time-series pixel data values at two different positions from the memory, respectively,
The method is characterized in that one time-series pixel data value is subtracted from the other time-series pixel data value at each corresponding time, and the values obtained by the subtraction are displayed as a graph.

[Effect]

In the graph display method of time-series image data of the present invention, by subtracting the temperature value at the start of measurement from the temperature value at each measurement point and displaying the graph with the starting point set as a reference value, for example, 0°C, This means that you can directly read the temperature change from This is particularly useful when trying to compare temperature changes at several different points on an object. According to the conventional example, it is difficult to compare temperature changes because the starting points of the graphs showing temperature changes at each point are different, but according to the present invention, the starting points of all graphs are at the reference value of 0°C. It becomes extremely easy to compare temperature changes. Furthermore, as a modification of this graph display method, two different points A and B are taken in the time-series temperature distribution image, and the difference B-A in temperature values between points A and B at the same time is displayed in a graph. In this way, it is possible to directly read the difference in the temperature change at point B when the temperature change at point A is taken as a reference, so the difference in temperature change between points A and B can be easily compared. .

〔Example〕 Examples will be described below with reference to the drawings.

FIG. 1 is a block diagram of a thermography apparatus for explaining one embodiment of the present invention, FIG. 2 is a diagram for explaining the storage area of the memory, and FIG. 3 is a diagram for explaining the graph display memory. 1 is a diagram for explaining writing of a pattern, 1 is a camera section, 2 is a diagram for explaining writing of a pattern;
is an A/D converter, 3 is a changeover switch, 4 is a write circuit, 5 is an image memory, 6 is a readout circuit, 7 is a synthesis circuit, 8 is a changeover switch, 9 is a display device, 10
1 is a cursor memory, 11 is a cursor position designation circuit, 12 is a cursor write circuit, 13 is a read circuit, 14 is an image memory section, 15 is a write circuit, 1
6 is a reading circuit, 17 is a changeover switch, 18 is a coordinate conversion circuit, 19 is a writing circuit, 20 is a graph display memory, 21 is a reading circuit, 22 is a scale writing circuit, 23 and 24 are data memories, and 25 is a subtraction circuit. shows.

In FIG. 1, a camera unit 1 two-dimensionally scans, condenses, and detects infrared rays emitted from an object to be measured to obtain an infrared image signal, and the infrared image signal is sent to an A/D converter 2. For example, the signal is converted into a digital signal of 8 bits per pixel and stored in the image memory 5 via the changeover switch 3 and the write circuit 4. The image memory 5 has 256 lines as shown in FIG.
256 pixels per line, 8 bits per pixel,
Temperature data of each pixel of an infrared video signal obtained by the camera section 1 is stored in a corresponding position in the memory area with an 8-bit dynamic range. This data is sequentially rewritten with new data, for example, once every second in accordance with the screen scanning of the camera section 1. The cursor memory 10, as shown in FIG. 12, a cursor pattern consisting of a horizontal cursor HC and a vertical cursor VC is written.

The image data and cursor pattern written in the image memory 5 and the cursor memory 10 are simultaneously read out by readout circuits 6 and 13, respectively, in synchronization with screen scanning of the display device 9, and are synthesized by a synthesis circuit 7. Therefore, the changeover switch 8 is connected to the synthesis circuit 7.
If the temperature distribution image Z, horizontal cursor HC, and vertical cursor VC as shown in FIG. Note that the configuration for displaying the horizontal waveform, vertical waveform, and temperature value at the cursor intersection point PC is not directly related and will therefore be omitted.

The temperature distribution image Z displayed on the display device 9 is rewritten every time the camera unit 1 scans the screen once per second. One screen's worth of time-series temperature distribution images are written into the image memory section 14 one after another every minute. Therefore, as shown in FIG. 1, the image memory section 14 stores image memories Z ₁ to _{Z 10} for 10 screens.
, the image memory section 14 will store 10 temperature distribution images taken at one minute intervals. Note that the memory contents of each of the image memories Z ₁ to _{Z 10} of the image memory section 14 are the same as those of the image memory 5.

After measuring for 10 minutes in this way, the changeover switch 3 is connected to the image memory unit 14 side, and the changeover switch is connected to the image memory 5 side, and when the operator specifies, for example, the first temperature distribution image Z, the readout circuit 16 reads the data stored in the image memory Z ₁ and stores it in the image memory 5 via the changeover switches 17 and 3 and the write circuit 4.
This image Z ₁ is continuously displayed on the display device 9.
At this time, both horizontal and vertical cursor patterns HC,
As described above, VCs are displayed in an overlapping manner.

Next, a case will be described in which a temperature difference graph display according to the present invention is performed. In this case, the changeover switch 17 is connected to the data memory 23 side, and the changeover switch 8 is connected to the graph display memory 20 side.
In this state, the readout circuit 16 first reads the temperature data of the pixel located at the cursor intersection point CP in the first temperature distribution image _Z1 stored in the image memory 14 based on the cursor position designation signal from the cursor position designation circuit 11. _A1 is read and stored in the data memory 23. Next, the changeover switch 17 is connected to the data memory 24 side, and the readout circuit 16 reads out the same temperature data A ₁ and stores it in the readout data memory 24 . The subtraction circuit 25 subtracts the temperature value stored in the data memory 23 from the temperature value stored in the data memory 24 and sends the result to the coordinate conversion circuit 1.
Send to 8. That is, the value _A1 stored in the data memory 23 becomes the reference value. In this case
Since A ₁ -A ₁ , 0 is sent to the coordinate conversion circuit 18. When this process is completed, the readout circuit 16 reads out the temperature data A ₂ of the pixel at the same position in the second temperature distribution image Z ₂ and stores it in the readout data memory 24 . Then, the subtraction circuit 25 performs A ₂ −
_A1 is calculated and the result is sent to the coordinate conversion circuit 18.
By repeating this process up to the temperature data A ₁₀ of the pixel located at the simultaneous series image data position in the last temperature distribution image Z ₁₀ , 10 temperature difference data A ₁
−A ₁ , A ₂ −A ₁ , A ₃ −A ₁ , ..., A ₉ −A ₁ , A ₁₀ −
You can get _A1 . These temperature difference data are written into the graph display memory 20 via the coordinate conversion circuit 18 and the write circuit 19. In this graph display memory 20, a graph pattern with time on the horizontal axis and temperature difference on the vertical axis is written in advance as shown in FIG. The vertical axis position corresponding to the bright spot is given, and the horizontal axis direction is written as 10 bright spots spaced apart for a certain period of time as shown in FIG. 3b. In addition,
The coordinate conversion circuit 18 plays a role of converting each temperature difference data value into position data in the vertical axis direction.

Furthermore, since it is difficult to see just a bright spot, Figure 3c
Make sure to also draw lines connecting each luminance as shown in . The data of this line can be easily created in the coordinate conversion circuit 18 or the writing circuit 19 based on the data of 10 points. Furthermore, Figure 3 d
As shown in , the scale writing circuit 22 writes scale values at one-minute intervals in the horizontal axis direction in the graph pattern based on the measurement time interval information Δt, and also writes information defining the temperature measurement range when acquiring the temperature distribution image, for example. Center temperature TC and temperature width TW (information such as upper limit temperature and lower limit temperature or lower limit temperature and temperature width may also be used)
Write the temperature along the vertical axis of the graph pattern based on . Information regarding this scale may be specified by the operator, but it is stored in the image memory unit 14 together with the image data during measurement, and when displaying a graph, it is read out separately from the image data using the readout circuit 16 and written on the scale. It may also be supplied to the circuit 22.

The graph pattern in which each piece of information has been written in this way is read out by the readout circuit 21 in synchronization with the screen scanning of the display device 9, and the changeover switch 8
Since the data is sent to the display device 9 via the display device 9, a graph as shown in FIG. 3d is displayed on the screen.

Note that a plurality of positions in the temperature distribution image may be designated and a plurality of temperature difference graphs may be displayed in a superimposed manner, and in this way, the contrast between different positions becomes clear.

Next, other embodiments of the present invention will be described.
FIG. 4 is a diagram for explaining another embodiment of the present invention. In another embodiment of the present invention, the configuration is the same as that in FIG. 1, except that two different points are designated by the cursor position designation circuit 11 and the calculations performed by the subtraction circuit 25 are different.

As shown in FIG. 4a, the cursor position designation circuit 1
1, two different points A in the image memory section 14,
When B is specified, the readout circuit 16 transfers the temperature data A 1 of the point A in the first temperature distribution image Z ₁ to the data memory ₂₃ and the temperature data B ₁ of the point B to the data memory using the switch 17 . The subtraction circuit 25 calculates B ₁ −A ₁ and sends the result to the coordinate transformation circuit 18 . Next, readout circuit 1
6 stores temperature data A ₂ at point A in the temperature distribution image Z ₂ in the data memory 23 and temperature data B 2 at point B in the data memory 24, and stores the temperature data A ₂ at point A in the temperature distribution image Z 2 in the data memory 24.
calculates B ₂ -A ₂ and sends the result to the coordinate conversion circuit 18. By repeating this process until the final temperature distribution image Z ₁₀ , 10 temperature difference data are obtained.
B ₁ −A ₁ , B ₂ −A ₂ , A ₃ −A ₃ , ..., B ₁₀ −A ₁₀ can be obtained. These 10 pieces of data are written into the graph display memory 20 via the coordinate conversion circuit 18 and the write circuit, and the process is the same as that described in the first embodiment of the invention. By doing this, a display as shown in FIG. 4b will be produced.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, it is now possible to directly read how the temperature of a certain point on the object to be measured changes over time, and it is also possible to directly read how the temperature at a certain point on the object to be measured changes over time. Since it is possible to directly read how much the temperature change differs from other points, it is easy to analyze various temperature characteristics.

[Brief explanation of the drawing]

Fig. 1 is a block configuration diagram of a thermography apparatus for explaining an embodiment of the present invention, Fig. 2 is a diagram for explaining a memory storage area, and Fig. 3 is a graph pattern in a graph display memory. FIG. 4 is a diagram for explaining another embodiment of the present invention. FIGS. 5 and 6 are diagrams for explaining the conventional display screen of a thermography device. It is. 1...Camera section, 2...A/D converter, 3, 8, 1
7... Selector switch, 4, 15, 19... Write circuit, 5... Image memory, 6, 13, 16, 21... Read circuit, 7... Synthesizing circuit, 9... Display device, 10...
Cursor memory, 11...Cursor position designation circuit,
DESCRIPTION OF SYMBOLS 12... Cursor writing circuit, 14... Image memory section, 18... Coordinate conversion circuit, 20... Graph display memory, 22... Scale writing circuit, 23, 24... Data memory, 25... Subtraction circuit.

Claims (1)

[Claims] 1. Read out time-series pixel data values at predetermined positions from a memory that stores time-series image data, subtract each first pixel data value from the time-series pixel data values, and A graph display method for time-series image data characterized by displaying obtained values as a graph. 2. Read out time-series pixel data values at two different positions from a memory that stores time-series image data, subtract one time-series pixel data value from the other time-series pixel data value at each corresponding time, and A graph display method for time-series image data characterized by displaying values obtained by subtraction as a graph.