KR101519995B1 - System for obtaining color image using modulated infrared rays - Google Patents

Abstract

The present invention relates to a modulation infrared color image acquisition system, comprising: an infrared ray irradiation device for irradiating two or more modulated infrared wavelengths to a subject; A color image acquiring device that senses two or more modulated infrared wavelengths irradiated by the infrared ray irradiator and reflected by the object, and converts and combines the two or more modulated infrared wavelengths to obtain a color image; And a synchronization device that is calibrated and synchronized with the color image acquisition device at a predetermined time, and adjusts the infrared irradiation time of the infrared irradiation device on a wavelength-by-wavelength basis.

Description

TECHNICAL FIELD [0001] The present invention relates to a modulated infrared color image acquisition system,

The present invention relates to a modulation infrared color image acquisition system, and more particularly, to a modulation infrared color image acquisition system that detects an infrared wavelength reflected by a subject through an infrared radiation device modulated by a modulation signal generator, Color to obtain a color image.

Conventional color image acquisition systems can process various wavelengths contained in visible light to produce a color image with a color similar to that seen with the naked eye. However, when the visible light is insufficient as in the case of indoor or nighttime, a proper input image can not be obtained due to a low input light signal. In addition, the color infrared image acquisition system has a problem in that the size of the device is increased and the price is expensive because the system uses two optical systems and two infrared sensors that can capture two colors in a satellite or an industry, respectively.

FIG. 1 shows a conventional visible light image acquisition system. As shown in FIG. 1 (a), a bright and clear image can be obtained when the sunlight and the illumination light have sufficient optical power It is difficult to obtain an appropriate image when the illumination light is below the minimum sensing level (for example, when it is dark as night, or when it is scattered by fog or dust) as shown in (b) of FIG.

On the other hand, the infrared image acquisition system requires a high-priced infrared sensor and can display the two-dimensional space temperature information on the screen, and the infrared information to be copied according to the high and low temperature can be expressed in black and white on the screen. That is, a general infrared image acquisition system expresses the quantity of infrared rays to be emitted in a monochromatic fashion according to the high and low temperature.

&Quot; A monolithically integrated plasmonic infrared quantum dot camera ", published in Nature Communications 2 (http://www.nature.com/ncomms/journal/v2/), published on Apr. 19, 2011,

As described above, the conventional color image acquisition system can not obtain an appropriate image in the case of a room or a night where there is a lack of visible light, so that it has a problem that it is not applicable to a security surveillance camera or a night vision of an automobile.

In order to solve such a problem, the present invention can provide a system for acquiring an infrared color image by providing an infrared ray irradiating device in a color image acquiring apparatus. In particular, by adding a modulation function using a modulation signal to the infrared ray irradiating apparatus of the present invention, the color image acquiring apparatus can perform color conversion correction of the infrared ray signal detected over time to obtain a color image, So that the subject can be recognized.

Also, in the case of an image pickup device (color sensor) which detects irradiated infrared rays and acquires them as color images, if there are three kinds of color sensors in the same area, there is a problem that the signal-to-noise ratio is reduced to 1/3, When irradiated with high power and reaching directly to the human eye, a problem of stability may occur.

In order to solve the above-mentioned problems, one aspect of the present invention proposes a modulation infrared color image acquisition system. The system includes an infrared ray irradiator for irradiating two or more modulated infrared wavelengths to a subject; A color image acquiring device that senses the at least two modulated infrared wavelengths irradiated by the infrared irradiating device and reflected by the object, and converts and combines the at least two modulated infrared wavelengths to obtain a color image; And a synchronization device, which is calibrated and synchronized with the color image acquisition device at a predetermined time, and adjusts the infrared irradiation time of the infrared ray irradiation device by wavelength. At this time, the synchronizing device includes a modulation signal generator for generating a modulating signal for adjusting the infrared irradiation time of the infrared ray irradiating device by wavelength, or a common time information sharing device for sharing the time information between the color image acquiring device and the infrared ray irradiating device do.

And the infrared ray irradiating device modulates and irradiates an infrared wavelength specified at a time determined by the modulation signal generator according to the modulated signal of the modulated signal generator, and the color image acquiring device irradiates the infrared And the arrival time is a time at which each of the two or more modulated infrared wavelengths reaches the color image acquiring device after being reflected by the subject .

According to the infrared color image acquisition system of the present invention, an infrared ray irradiating device is provided and by operating to convert the infrared wavelengths sensed through the color image acquisition device into wavelengths in the visible light band, Function can be added, and low-cost production becomes possible.

It works effectively on devices such as a security device or a night vision device so that an infrared color image can be obtained even when there is a lot of nighttime, mist, and dust. In particular, in the case of automobile night vision, the infrared ray reflection and scattering characteristics of human skin and cloth are emphasized, so that the object can be displayed more clearly, which can contribute to driving safety.

In addition, sensitivity can be improved because multiple colors can be detected with only one sensor without using a plurality of color sensors. With respect to the safety problem, the infrared ray irradiated in the present invention has an advantage that it is relatively safe because the irradiation time is short and the power is low.

1 shows examples of images according to a conventional visible light acquisition image system.
2 is a block diagram illustrating a configuration of a modulation infrared color image acquisition system according to an embodiment of the present invention.
3 is a block diagram illustrating a modulation infrared color image acquisition system according to another embodiment of the present invention.
4 illustrates two or more wavelengths detected through a modulation infrared color image acquisition system according to an embodiment of the present invention.
5 (a) to 5 (c) illustrate the steps of detecting two or more wavelengths through a modulation infrared color image acquisition system according to an embodiment of the present invention.
FIG. 6 illustrates an example of wavelength conversion for obtaining a color image through an infrared color image acquisition system according to an embodiment of the present invention. Referring to FIG.
In the drawings, the same reference numerals denote the same elements.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference numerals even though they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive. In this specification, when it is mentioned that a certain element includes an element, it means that it may further include other elements.

2 is a block diagram illustrating a configuration of a modulation infrared color image acquisition system according to an embodiment of the present invention. The modulated infrared color image acquisition system proposed by the present invention includes an infrared ray irradiating device 210 for irradiating two or more infrared wavelengths to a subject 250, a plurality of infrared rays irradiated by the infrared ray irradiating device 210, A color image acquiring device 230 that senses an infrared wavelength, converts and combines infrared wavelengths to acquire a color image, and a color image acquiring device 230 that are calibrated and synchronized at a predetermined time, And a modulation signal generator 220 for adjusting the infrared irradiation time of each wavelength by wavelength. The infrared ray irradiating device 210, the color image acquiring device 230, and the modulation signal generator 220 may be synchronized with each other by transmitting / receiving a synchronization signal to / from each other at predetermined periods or time intervals. In the present embodiment, the components 210, 220, and 230 are shown as being integrated, but the present invention is not limited thereto. In addition, the modulation signal generator 220 and the color image acquisition device 230, which are synchronization devices, may be implemented in a form including software, an arithmetic unit, and communication means for implementing the functions described in the present invention.

The infrared ray irradiating device 210 is an infrared ray irradiating device having a multi-wavelength or a wide wavelength bandwidth, and can irradiate the object 250 with a plurality of infrared wavelengths representing different wavelengths. The optical power as well as the wavelengths to be examined can be investigated differently. In another embodiment, the infrared ray irradiating device 210 may be implemented to include a plurality of infrared ray irradiating devices with different wavelengths.

The modulation signal generator 220 is a device for transmitting the modulation signal to the infrared radiation apparatus 210 in a corrected and synchronized manner with the image acquisition apparatus 230 at a predetermined time interval. The infrared radiation apparatus 210 Modulates the infrared wavelength specified at the time determined according to the adjustment of the modulation signal generator 220 and checks. That is, the modulated signal generator 220 generates a modulated signal so that the infrared irradiation time of the infrared ray irradiating apparatus is separately adjusted for each wavelength, and the infrared powers are modulated and irradiated according to the modulated signal. The modulated signal may be generated according to the wavelength-time data stored in advance in the color image acquiring apparatus, and the generated modulated signal is transmitted to the infrared ray irradiating device to change the infrared ray power and wavelength to be irradiated with time. The infrared power modulated by the modulated signal may be in the form of Fourier-synthesized standing waves. For example, a square wave, a sine wave, a triangle wave, or a combination thereof.

Although the modulation signal generator 220 is mainly described as an example of a synchronization apparatus for performing synchronization and modulation between the color image acquisition apparatus 230 and the infrared ray irradiation apparatus 210 in the present embodiment and the detailed description, The synchronization device of the present invention may include other types of synchronization devices such as a common time information sharing device sharing time information between the color imaging device and the infrared irradiation device, and the configuration may be separate or integral.

The plurality of modulated infrared wavelengths irradiated are radiated, reflected or scattered by the object 250, and the light can be detected by the color image acquisition device 230.

The color image acquisition device 230 is a device that detects light reflected or scattered from a subject and converts the light into a color image. The color image acquiring device 230 can sense a plurality of infrared wavelengths in an infrared band (for example, a band of 800 nm or more and 1100 nm or less) using an imaging device (e.g., a CCD device of a camera). The color image acquiring device 230 is sensed in accordance with the color filter characteristics of the imaging device, and may employ, for example, a silicon (Si) imaging device.

Particularly, the color image acquisition apparatus 230 of the present invention can predefine and store wavelength-time data indicating the relationship between each wavelength and arrival time for two or more infrared wavelengths. That is, it is possible to specify in advance which wavelength is irradiated and the wavelength at which the reflected scattered light arrives at the color image acquiring device 230. At this time, the arrival time may be recorded as an arrival time or a time difference within one cycle (for example, the first arriving wavelength is R (Red) and the second arriving wavelength is G (Green)) for each wavelength. The wavelength-time data may also include wavelength-color data that is assigned a different color (e.g., R, G, B) for each wavelength so that the relationship between wavelength, color, Can be defined.

For example, a color image acquisition device may include a silicon detector, and the silicon detector may be a monochrome sensor, but by defining which wavelengths are irradiated at any time, the detected infrared wavelengths can be implemented in color Do. As another example, GaAs, InP series material detectors or bolometers with high sensitivity in the infrared band may be applied. As described above, since color images can be obtained using one sensor, there is an advantage that the signal-to-noise ratio is excellent in the same area sensor as compared with the conventional technique using several color sensors.

Meanwhile, as another embodiment, the color image acquiring device 230 may include a sensor for measuring the amount of visible light. The infrared ray irradiating device is operated so that when the visible light amount is lower than the threshold value through the visible light amount measuring sensor, the infrared ray irradiating device can be operated flexibly. That is, when the color image acquisition is easy due to sufficient natural light (or illumination light), it functions as a general color image acquisition device 230, and only when natural light (or illumination light) So as to perform conversion into a color image using wavelengths.

The color image acquiring device 230 can sense a plurality of infrared wavelengths having different wavelengths and optical powers, and can convert and combine sensed wavelengths to represent a color image. The detection and conversion of the wavelength will be described in more detail below with reference to FIGS. 5 and 6. FIG.

3 is a block diagram illustrating a modulation infrared color image acquisition system according to another embodiment of the present invention. The infrared color image capturing system of the present invention may include a color image capturing apparatus 230 having a visible light interception filter 330.

The color image acquiring device 230 having the visible light cut-off filter 330 is realized so as to be operable under daylight or visible light illumination in which visible light is irradiated. The visible light cutoff filter 330 operates to reflect, absorb, or disappear visible light so that only the infrared light is passed, thereby allowing the color image capturing apparatus 230 to detect only infrared wavelengths. At this time, the visible light cutoff filter 330 preferably has a cutoff frequency of 700 nm to 940 nm and blocks visible light.

4 illustrates two or more modulated infrared wavelengths detected through a modulation infrared color image acquisition system according to an embodiment of the present invention. The color image acquiring device 230 can detect a plurality of modulated infrared wavelengths reflected and scattered from the subject and interprets the detection time (i.e., arrival time) or time difference of the detected modulated infrared wavelengths, It becomes possible. Also, the order detected within one period may be used in consideration of time other than the detection time and the detected time difference.

As described above, the color image acquiring device 230 can preliminarily prescribe and store the wavelength-time data defining the relationship between the wavelength and the arrival time of each wavelength, and converts the detected infrared wavelengths into a color image . The wavelength-time data may include wavelength-color data that assigns different colors to respective wavelengths.

As shown in FIG. 4, the infrared short wavelength 410, the infrared middle wavelength 420, and the infrared long wavelength 430 can reach the color image acquiring device 230 at specific time intervals in one cycle. The color image acquiring device 230 may detect the wavelength of each wavelength for one period or detect it a plurality of times to obtain the modulated infrared wavelength irradiated for one period. For example, the A wavelength may be detected once per cycle, and the B wavelength may be detected twice, depending on the nature of the wavelength, by varying the detection frequency for each wavelength. Considering the time of each of the obtained modulated infrared wavelengths as shown in FIG. 4, the color represented by each wavelength can be derived according to the wavelength-time data. For example, it can be detected that the infrared short wavelength 410 indicates red, the infrared middle wave 420 indicates green, and the infrared long wavelength 430 indicates blue. In this case, it is easiest to detect once for each wavelength in one period. However, when a sensor having a low sensitivity is used, it is possible to measure each wavelength for a period of several times using one characteristic of a long wavelength and a relatively small wavelength, The sensitivity compensation can be performed.

As described above, it is possible to detect specific colors using two or more detected infrared wavelengths and color information (wavelength-color data) assigned thereto, and to obtain color images by combining them according to the conversion and combination method. That is, the color image acquisition device 230 may convert and combine two or more modulated infrared wavelengths into color images using a linear, nonlinear, or empirical mapping algorithm. The conversion and the combination into the color image will be described in more detail with reference to FIGS. 5 and 6. FIG.

5 (a) to 5 (c) illustrate the steps of detecting two or more wavelengths through an infrared color image acquisition system according to an embodiment of the present invention. 5A shows optical powers of a plurality of infrared wavelengths sensed by the color image acquiring apparatus 230. FIG. 5B shows relative sensitivities of a plurality of sensed infrared wavelengths, and FIG. FIG. 5 (c) shows the wavelengths of the sensitivity and the optical power of the infrared wavelengths.

As described above, the infrared ray irradiating device 210 can have a multi-wavelength or a broad wavelength bandwidth, and can irradiate the object 250 with a plurality of modulated infrared wavelengths modulated according to the modulated signal, The plurality of modulated infrared wavelengths are radiated, reflected or scattered by the subject 250, and the light can be detected by the color image acquisition device 230.

The color image acquisition device 230 can sense a plurality of modulated infrared wavelengths in the infrared band. For example, as shown in FIG. 5 (a), three wavelengths can be detected and optical powers of three wavelengths can be detected. The optical power may be detected in the same manner as in FIG. 5 (a), and sensitivity and optical power of the wavelength may be detected differently as shown in FIG. 5 (c) according to the relative sensitivity shown in FIG. 5 It is possible.

5 (b), each wavelength is a wavelength having a constant interval or an arbitrary interval, and is converted into another color such as R (Red), G (Green), and B Lt; / RTI > For example, the wavelength is detected in an infrared band in the range of 800 nm to 1000 nm, and the half-width of the wavelength is preferably 0.5 nm or more and 1 μm or less. Further, as described above, it is possible to have predetermined wavelength-time data and wavelength-color data as to which wavelength exhibits a certain color when detecting an infrared wavelength, and accordingly, considering the time at which each wavelength reaches, It is possible to detect the color represented by the color.

As such, the color image acquiring device 230 is capable of sensing a plurality of modulated infrared wavelengths in the infrared band and is capable of sensing power, or infrared wavelength and power-time data, and wavelength - convert the modulated infrared wavelengths obtained by referring to the color data and combine them to obtain a color image. The conversion of infrared wavelengths will be described in more detail below with reference to FIG.

6 illustrates an example of wavelength conversion for obtaining a color image through a modulation infrared color image acquisition system according to an embodiment of the present invention. The color image acquiring device 230 can sense a plurality of infrared wavelengths having different wavelengths as shown in Figs. 5A to 5C, and can convert and combine them to obtain a color image .

6 shows an example of color image acquisition using wavelength shift as an example of wavelength conversion. The color image acquisition device 230 can sense three different modulated infrared wavelengths as shown by the dotted line and move the wavelength to the visible light band through the wavelength shift. Wavelengths shifted to the visible light band are recognized as wavelengths representing different colors, and different colors can be displayed. In this embodiment, three wavelengths (for example, wavelengths that can be expressed by R, G, and B) are used. However, the present invention is not limited thereto and various colors can be represented by using two or three or more wavelengths. By obtaining the visible light wavelengths expressing the basic colors in this manner, it becomes possible to realize more various colors by combining them.

In addition to the shift of the wavelength, it is possible to correct to the same signal size by appropriately correcting the magnitude of the wavelengths having different optical powers and sensitivities as shown in Fig. 5 (c). In addition, although the wavelength shift is exemplified in the present embodiment, various methods of converting two or more infrared wavelengths into color images using visible, linear, nonlinear, or empirical mapping algorithms are utilized .

Since the color image acquisition device 230 operates to convert the detected infrared wavelengths into wavelengths in the visible light band, the conventional infrared image acquisition system can be simply supplemented to enable a color image acquisition system, It is possible to add and enable low-cost production. In addition, it effectively works on devices such as security devices and night vision, so that infrared color images can be obtained even in the case of night, mist, dust, etc. In particular, in the case of automobile night vision, emphasis is given to the infrared reflection and scattering characteristics of human skin, cloth, so that objects can be more clearly displayed, thereby helping to improve driving safety.

In addition, since a plurality of colors can be detected with only one sensor without using a plurality of color sensors, the signal-to-noise ratio can be improved. In connection with the safety problem, the present invention has an advantage that it is relatively safe because the power is adjusted by modulating the time when the infrared ray is irradiated. In particular, for wavelengths close to visible light, the irradiation time is shortened, and the longer the wavelength, the safer it is.

While the present invention has been described in detail in the foregoing for the purpose of illustration, it is to be understood that the components, their connections and relationships, and their functions are merely exemplary. In the present invention, the infrared illuminating device 210, the modulation signal generator 220, the color image acquiring device 230, and / or the visible light blocking filter 330 included in the infrared color obtaining system are implemented as being physically integrated However, each of the components may be implemented in a physically separated form or in an integrated form of one or more components as needed, or may be composed of a device including a computing device, software, and communication means.

The present invention is not necessarily limited to these embodiments, as all the constituent elements constituting the embodiment of the present invention are described as being combined or operated in one operation. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them.

Furthermore, the terms "comprises", "comprising", or "having" described above mean that a component can be implanted unless otherwise specifically stated, But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

210: Infrared ray irradiator
220: Modulation signal generator
230: Color image acquisition device
250: Subject
330: Visible light filter

Claims (17)

A modulated infrared color image acquisition system,
An infrared ray irradiating device for irradiating the subject with two or more modulated infrared wavelengths;
A color image acquiring device that senses the at least two modulated infrared wavelengths irradiated by the infrared irradiating device and reflected by the object, and converts and combines the at least two modulated infrared wavelengths to obtain a color image; And
And a synchronization device that is calibrated and synchronized with the color image acquisition device at a predetermined time and adjusts the infrared irradiation time of the infrared ray irradiation device by wavelength,
Wherein the synchronizing device includes a common time information sharing device for sharing time information between the color image acquiring device and the infrared irradiating device,
Wherein the infrared ray irradiating device and the color image acquiring device share time information through the common time information sharing device,
The infrared ray irradiating apparatus modulates and examines the power and wavelength of infrared rays according to the shared time information,
Wherein the color image acquiring device preliminarily specifies, for the two or more modulated infrared wavelengths, wavelength-time data representing a relationship between respective wavelengths and arrival times. The method according to claim 1,
The synchronization device comprising:
Further comprising a modulation signal generator for generating a modulation signal for adjusting the infrared irradiation time of the infrared ray irradiating device by wavelength,
Wherein the infrared ray irradiating device modulates an infrared wavelength specified at a time determined according to the adjustment of the modulation signal generator according to a modulation signal of the modulation signal generator. delete delete The method according to claim 1,
Wherein the arrival time is a time at which each of the two or more modulated infrared wavelengths reaches the color image acquisition device after being reflected by the object. The method of claim 5,
Wherein the arrival time is expressed by a time difference of a time at which each of the two or more modulated infrared wavelengths of the infrared reaches the color image acquiring device. The method according to claim 1,
Wherein the wavelength-time data comprises wavelength-color data that is assigned a different color at each wavelength. The method of claim 7,
Wherein the color image acquisition device detects and combines the color of the sensed wavelength using the wavelength-time data and the wavelength-color data. The method according to claim 1,
Wherein the color image acquisition device detects one or more times of the two or more modulated infrared wavelengths at each synchronization time. The method according to claim 1,
Characterized in that there are two or more infrared irradiating devices, each of which is adjusted by the synchronizing device. The method according to claim 1,
Wherein the color image acquisition device converts and combines the at least two modulated infrared wavelengths into a color image using a linear, nonlinear, or empirical mapping algorithm. The method according to claim 1,
Wherein the color image acquisition apparatus further comprises a visible light cutoff filter. The method of claim 12,
Wherein the visible light cutoff filter has a cutoff frequency of 700 nm or more and 940 nm or less. The method according to claim 1,
Wherein the two or more modulated infrared wavelengths irradiated by the infrared irradiation apparatus have a half-width of 0.5 nm or more and 1 μm or less, respectively. The method according to claim 1,
The color image acquiring apparatus further comprises a visible light measuring sensor for measuring an amount of the visible light ray to be sensed,
And generates an operation signal for operating the infrared ray irradiating device when the measured amount of the visible light ray is lower than a predetermined reference value. The method according to claim 1,
Wherein the color image acquiring device, the infrared ray irradiating device, and the synchronizing device transmit / receive a synchronizing signal to / from each other at predetermined periods or time intervals. The method of claim 2,
Wherein the infrared ray modulated by the modulated signal of the modulated signal generator is a form in which a standing wave is fourier-synthesized.

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