JPH04192896A - Infrared-ray image pickup device - Google Patents

Abstract

PURPOSE:To facilitate the observation of brightness distribution by using a maximum/minimum value latch section to acquire a maximum value and a minimum value of a digital video signal changing at every screen and changing an input LUT so as to apply gradation conversion between the maximum value and the minimum value. CONSTITUTION:A maximum/minimum value holding section 4 holding the maximum, the minimum value of a digital video signal changing at every screen outputted from an A/D converter section 3 is provided on this device. Moreover, the number of gradation in an input lookup table (input LUT) ROM 5 is increased more than that of a conventional device and a processor 9 issues an instruction to the switching based on the data of the maximum/minimum value holding section 9. Thus, even when the brightness distribution of the inputted digital video signal is concentrated in a comparatively narrow range and the width is hourly changed, the gradation is optimizingly switched in response to the change and the brightness distribution is easily observed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an infrared imaging device that captures infrared radiation from a subject and images it.

[Conventional technology]

FIG. 3 is a diagram showing a conventional infrared imaging device of this type. In Figure 3, (1) is an infrared camera that captures the infrared rays emitted from the surface of the subject and converts it into an analog video signal, and (2) is the average value of the output of the analog video signal output from this infrared camera (1). (3) is an analog/digital converter that digitizes the analog video signal output from the autopedestal section (2); (18) is an input lookup table ROM2 (hereinafter abbreviated as input LUT ROM2) that performs gradation conversion of the daily video signal output from this analog/digital converter (3), (61 is this input LUT ROM2 (18)
Infrared camera +
Effects of 11 itself (device defects, shading, etc.)
(7) is a digital/analog conversion unit that converts the corrected digital video signal output from the image correction unit (6) into an analog video signal;
(8) is a display that displays the analog video signal output from this digital/analog converter (7);
9) is a processor that controls each of the above devices; 01 is an operation unit for a person to give instructions to the processor (9);
(11) is an operating unit interface that converts instructions from the operating unit a0 into digital signals.

Next, the operation will be explained. In a conventional infrared imaging device, an analog video signal output from an infrared camera (1) is converted into an analog/digital converter m (31) by converting the average value of the output of the analog video signal into an autopedestal section (2). The signal is then converted into a digital signal in the analog/digital converter (3) and subjected to gradation conversion in the input LUTROM2 (1g).This input UT ROM2 (1g) contains five types of gradation conversion patterns. is recorded and two people are operating the operation unit 00.
) and the operating unit interface (11) to instruct the processor (9) which of the five gradation patterns to select. The digital video signal output from input LUT ROM2 (1g) is then sent to an infrared camera (
1) Shadow W imposed by itself (difference in output level due to element defects).

The image is corrected via an image correction section for correcting shading, etc.), and is converted into an analog video signal by a digital/analog conversion section (7) and displayed on a display (8).

[Problem to be solved by the invention]

The infrared imaging device having the above configuration has the following problems.

In other words, since the input LUT ROM has only five gradation levels and must be switched from the operation panel, the luminance distribution of the input digital video signal is concentrated in a relatively narrow range, and It was not possible to observe the detailed cicada intensity distribution when its width changed.

This invention was made to solve the above-mentioned problems, and even when the brightness distribution of an input digital video signal is concentrated in a relatively narrow range and the width changes over time, it is possible to The purpose is to optimally switch the gradation according to the change, making it easier to observe the luminance distribution.

[Means to solve the problem]

The infrared imaging device according to the present invention includes, in addition to the conventional device described above, a maximum value/minimum value holding section that holds the maximum and minimum values of the signal that changes for each screen of the digital video signal output from the analog/digital conversion section. and input LU
The number of gradations in TROMI is increased compared to the conventional device, and the processor instructs the switching based on the data in the maximum value/minimum value holding section.

Further, an infrared imaging device according to another aspect of the present invention has two sets of input LUT ROM1 having the above configuration.
In place of UT RAMI and 2, it is also output from the analog/digital converter.

an input switching unit 1 or 2 for switching which of the two sets of LUT RAMI or 2 the Zicle video signal is input to according to a command from the processor; and the two sets of input LUs.
and an output switching unit 1 or 2 which switches which of the gradation-converted digital video signals output from the T RAMI or 2 is to be input to the image correction unit according to an instruction from the processor, and has the maximum value / Based on the data from the minimum value holding section, the processor selects the optimum gradation conversion straight line from the input LUT RAM 1 or 2 that is not selected by the input and output switching section 1 or 2. Or write in 2.

When writing is completed, the input/output switching unit 1 or 2 is operated so as to switch the path of the digital video signal to the input LUT RAMI or 2 to which the data has been written.

[Effect]

In this invention, the maximum and minimum values of the digital video signal outputted from the analog/digital converter that change during one screen are captured by the maximum/minimum value holding section, and the minimum and maximum values are captured. Since the input LUT is changed so that gradation conversion is performed between The gradation is optimally switched according to the change, making it easy to observe the brightness distribution.

〔Example〕

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

In FIG. 1, (1) to (3) and (6) to (11) are exactly the same as the conventional device described above. (4) is a maximum value/minimum value holding unit that holds the maximum and minimum values of the digital video signal output from the analog/digital converter (3), which changes for each screen; (5) is the analog /Input lookup table RO that performs gradation conversion of the digital video signal output from the digital conversion unit (3)
It is M1.

In the infrared imaging device configured as described above, the analog video signal output from the infrared camera (1) is converted into an average value of the output by the autopedestal section (2) and then converted to the input dynamic signal of the analog/digital conversion section (3). Adjusted to match the center of the range.

Next, it is converted into a digital signal in an analog/digital converter (3). The maximum and minimum values of the digital video signal output from this analog/digital converter (3) that change for each screen are held in the maximum/minimum value holding unit (4), and this data is also stored. The processor (9) selects the LU closest to the gradation conversion that connects the minimum value and maximum value.
Select T and switch input LUTROM1.

Next, FIG. 2 is a diagram showing an embodiment of another invention according to the present invention. In Figure 2, (1) to (4) and (6)
-(11) are exactly the same as in FIG.

(12) and [13] are the analog/digital converter (
3) The digital video signals output from the two sets of input L
Input switching units 1 and 2.UT RAMI and 2 (14) and 2. (14) and (15) are processors (
9) rewritable input LUT RAMI and 2.
(16) and (I7) are the above two sets of input LUT RA
The image correction unit (6) selects which of the gradation-converted digital video signals output from the MI and 2 (14) (Is).
These are output switching units 1 and 2 that switch between inputs.

In the infrared imaging device configured as above, the infrared camera (1) outputs an analog video signal, and the average value of the output is input to the analog/digital converter (3) at the autopedestal section (2). Adjusted to match the center of the dynamic range.

Next, it is converted into a digital signal in analog/digital conversion M(3). The maximum and minimum values of the digital video signal outputted from this analog/digital converter (3), which change for each screen, are held in the large value/minimum value holding part (4), and this data is Based on this, the processor (9) converts the gradation conversion straight line connecting the maximum value and the minimum value to the input LUTRAM 1 or 2 (14) (14) which does not contain the input from the analog/digital converter (3).
15). Upon completion of this writing, the processor (9) sends data from the analog/digital converter (3) to the image corrector (6).

Switching the path of the digital video signal (input switching unit 1 or 2
．． Output switching unit 1 or 2) Next input LUTRAMI or 2
(Start writing to 141(15).

〔Effect of the invention〕

As described above, according to the present invention, the luminance distribution of the input digital video signal is concentrated in a relatively narrow range,
Furthermore, even if the width changes over time, the gradation can be optimally switched according to the change, making it easier to observe the brightness distribution.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing one embodiment of the infrared imaging device of the present invention, Fig. 2 is a diagram showing another embodiment of the invention, Fig. 3+,
1 is a diagram showing a conventional infrared imaging device. In the figure, (1) is an infrared camera, (2) is an autopedestal section, (3) is an analog/digital conversion section, and (4) is an infrared camera.
) is the maximum value/minimum value holding section, (5) is the input pull-up table ROMI, f61 is the image correction section, (7) is the digital/analog conversion section, (8) is the display, (
9j is a processor, (10tl is an operating section, (11) is an operating section interface, (12) is an input switching section 1.(
13) is an input switching unit 2, and (14) is an input lookup table RAMI. (15) is the input lookup table RAM 2 ,
(16) is the output switching section 1. (17) is the output switching section 2.
(18) is an input lookup table ROM2. Note that the same reference numerals in the two figures indicate the same or equivalent parts.

Claims (2)

[Claims] (1) An infrared camera that captures the infrared rays emitted by the subject and converts it into an analog video signal, and an automatic system that matches the average output value of the analog video signal output from this infrared camera with the center of the input dynamic range of the analog/digital converter. A pedestal section, an analog/digital conversion section that converts the analog video signal output from the autopedestal section into a digital video signal, and a signal that changes for each screen of the digital video signal output from the analog/digital conversion section. a maximum value/minimum value holding section that holds the maximum and minimum values of the digital video signal; an input lookup table ROM that performs gradation conversion of the digital video signal output from the analog/digital conversion section; and this input lookup table ROM. an image correction unit for correcting the influence of the infrared camera itself on the digital video signal output from the image correction unit; and a digital/analog conversion unit for converting the corrected digital video signal output from the image correction unit into an analog video signal. a display for displaying the analog video signal output from the digital/analog converter, a processor for controlling each of the above devices, an operation section for giving instructions to the processor, and instructions from the operation section. An infrared imaging device characterized by comprising: an operation unit interface that converts the image into a digital signal. (2) An infrared camera that captures the infrared rays emitted by the subject and converts it into an analog video signal, and an automatic system that matches the average output value of the analog video signal output from this infrared camera with the center of the input dynamic range of the analog/digital converter. A pedestal section, an analog/digital conversion section that converts the analog video signal output from the autopedestal section into a digital video signal, and a signal that changes for each screen of the digital video signal output from the analog/digital conversion section. The maximum value that holds the minimum value of /
A minimum value holding section, two sets of input lookup table RAMs that perform gradation conversion of the digital video signal output from the analog/digital conversion section, and a processor that converts the digital video signal output from the analog/digital conversion section. an input switching unit that selects which of the two sets of input lookup tape RAMs is to be input based on a command from the input lookup table RAM, and which of the gradation-converted digital video signals output from the two sets of input lookup table RAMs; an output switching unit that switches between the two according to instructions from the processor; an image correction unit that corrects the influence of the infrared camera itself on the digital video signal output from the output switching unit; A digital/analog conversion unit that converts the digital video signal into an analog video signal; a processor that controls the above-mentioned devices; and an operation unit that gives instructions to the processor. An infrared imaging device comprising: and an operating section interface that converts an instruction from the operating section into a digital signal.