JP2005164349A - Distance detecting method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize speed-up in distance detection, consideration of the influence of external light, creation of a key signal, and reduction in noise. <P>SOLUTION: The method comprise: irradiating a subject with light modulating in intensity with first characteristics; detecting changes in reflected light from the subject to set a first image signal; irradiating the subject with light modulating in intensity with second characteristics different from the first characteristics; detecting a change in reflected light from the subject to set a second image signal; performing distance calculations from the first image signal and the second image signal; setting a distance image which displays the distance from the subject with light and darkness of images; and outputting the distance image. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a distance detection method and apparatus for detecting a distance image representing a distance between a camera and a subject in real time.

  An image laser radar device disclosed in Patent Document 1 has a laser light source that is luminance-modulated at a predetermined frequency and projects emitted light onto a subject, and a function that receives reflected light from the subject and enhances the image, and has a predetermined frequency. An image intensifier tube whose gain is modulated by the gate, and a gate that turns on the output of the image intensifier only during a period in which the gain monotonously increases or decreases with a period of approximately ¼ or less of the gain modulation period. Means, and the period is synchronized, so that information in which the shade changes periodically according to the distance can be obtained, and the distance measurement result is obtained in the shade image.

Japanese Patent Laid-Open No. 2004-260688 forms a subject illuminated with illumination light having a predetermined luminance as an optical image, and detects three-dimensional information for detecting the distance of each point of the subject from an image obtained by capturing the optical image with a predetermined imaging gain. A detection method in which at least one of the predetermined luminance and imaging gain changes with time, whereby the distance of each point of the subject can be detected at a speed that follows the frame time of the video signal in real time. It is what you want to do. By using the luminance or imaging gain that changes with time, a two-dimensional luminance distribution of the image of the captured subject is obtained, and this luminance distribution includes distance information to each point of the subject. 3D information can be detected.
JP-A-6-294868 JP 2000-121339 A

  The invention disclosed in Patent Document 1 has a two-dimensional raster scan of the illumination light beam and a change in the modulation phase of the illumination light, so that it is difficult to capture the stereoscopic information of the subject at the speed of the frame time of the video signal. Since it is unsuitable to be applied to the imaging of a stereoscopic moving image, the invention disclosed in Patent Document 2 aims to detect stereoscopic information of a subject within a frame of a video signal.

  The present invention further advances the invention according to Patent Document 2 described above, and provides a new arithmetic processing method and arithmetic process for a distance video signal, thereby speeding up distance detection and considering the influence of external light. An object is to realize generation of a key signal and reduction of noise.

  Therefore, the first distance detection method according to the present invention irradiates the subject with light that is intensity-modulated with the first characteristic, detects a change in reflected light from the subject, and sets the first video signal as the first video signal. Irradiating the subject with light that is intensity-modulated with a second characteristic different from the first characteristic, detecting a change in the reflected light from the subject to form a second video signal, and the first video signal and the second video signal Therefore, the distance calculation calculation is performed by the following formula 1, and the distance video is output with the distance between the subject as the distance video indicating the brightness of the image.

  The first distance detecting apparatus according to the present invention irradiates a subject with light whose intensity is modulated with the first characteristic, detects a change in reflected light from the subject, and uses the first video signal as a first video signal. Video signal detection means: a second video signal that irradiates the subject with light that is intensity-modulated with a second characteristic different from the first characteristic, detects a change in reflected light from the subject, and generates a second video signal Detection means: distance video calculation means for performing distance calculation calculation by the following formula 1 from the first video signal and the second video signal, and making the distance between the subject a distance video indicated by the brightness of the image And output means for outputting a distance image.

  Here, d is the distance, V1 is the first video signal, V2 is the second video signal, and α is a constant.

  In the prior art, it has been difficult to detect distances with a large number of pixels, but it is possible to detect distances with a large number of pixels and at a high speed by calculating the video signal using the above formula.

  In the distance detection method and apparatus, the first video signal and the second video signal are alternately acquired for each frame of the television video signal, and the distance video is sequentially updated in units of frames. Is desirable. As a result, it becomes possible to obtain a distance image that follows the video frame rate of the TV signal. Therefore, two types of image signals are acquired in units of frames, the distance image is calculated sequentially in the preceding and following frames, and the TV signal It is possible to output a distance image following the video frame rate.

  Further, it is preferable that the first video signal and the second video signal are stored in a memory and then read out for calculation.

  In the second distance detection method according to the present invention, the subject is irradiated with light whose intensity is modulated with the first characteristic, the change in the reflected light from the subject is detected, and the first video signal is obtained. The object is irradiated with light that is intensity-modulated with a second characteristic different from the above-mentioned characteristic, a change in reflected light from the object is detected and used as a second video signal, and the object is photographed in a state where no light is irradiated. 3 is detected, and a distance calculation operation is performed from the first video signal, the second video signal, and the third video signal according to Equation 2 below, and the distance between the subject and the subject is determined as the brightness of the image. The distance image shown in Fig. 6 is to be output.

  Furthermore, the second distance detection device according to the present invention irradiates the subject with light that is intensity-modulated with the first characteristic, detects a change in reflected light from the subject, and sets the first video signal as the first video signal. Video signal detection means: a second video signal detection that irradiates the subject with light that is intensity-modulated with a second characteristic different from the first characteristic, and detects a change in reflected light from the subject to generate a second video signal. Means: Photograph a subject in a state where no light is irradiated, and detect a third video signal. Third video signal detection means: the first video signal, the second video signal, and the third video signal. And a distance video calculation means that performs distance calculation calculation according to the following formula 2 and sets the distance between the subject as a distance video indicating the brightness of the image; and an output means that outputs the distance video. It is in.

  Here, d is the distance, V1 is the first video signal, V2 is the second video signal, V3 is the third video signal, and α and β are constants.

  Thus, the third video signal that does not irradiate light is detected, and the influence of external light can be eliminated by calculating with the above mathematical formula, so that more accurate distance detection is possible.

  In addition, it is preferable that the first video signal, the second video signal, and the third video signal are acquired within a frame of a television video signal, and the distance video signal is updated and output at a video rate. Thereby, by capturing all of the first video signal, the second video signal, and further the third video signal necessary for calculating the distance video signal within the video frame time (1/60 seconds) of the television signal, It is possible to eliminate edge detection errors that occur when shooting a moving subject.

  Furthermore, it is preferable that the first video signal, the second video signal, and the third video signal are stored in a memory and then read out for calculation.

  Furthermore, it is desirable to simultaneously output an image obtained by binarizing the calculated distance video signal at a predetermined threshold video level. Thus, a key signal necessary for image composition based on distance information can be output.

  Also, a filter for smoothing the boundary line of the binarized image is provided by taking the majority by taking the sum of the level values of a plurality of pixels around the pixel with respect to the binarized image at a predetermined threshold video level. Is desirable.

  In the above formula, it is desirable to vary the value of the constant α. As a result, the coefficient can be variably adjusted, so that the dynamic range of the video signal level can be widened, the measurement resolution can be improved, and the measurement range can be expanded.

  Furthermore, when the sum of the first video signal and the second video signal is equal to or less than a predetermined value, it is desirable to set the distance calculation result to 0 value. As a result, when the captured video signal level is low, particularly when the value is close to 0, the noise component increases rapidly when the calculation process is performed using the above formula. Therefore, the distance detection calculation is performed for pixels below a certain threshold. This is to avoid the increase in noise.

  Furthermore, it is desirable that the angle of view adjustment between the color image and the distance image from the camera that captures the color image is performed by changing the effective pixel area of the image sensor used for the distance detection. This makes it possible to electrically adjust the angle of view of a color image and a distance image, which has been difficult by adjusting only the optical system, with high accuracy.

  In addition, it is desirable to provide a delay circuit for adjusting a time lag caused by arithmetic processing between the color video signal and the distance video signal in the output line of the color video signal. As a result, a delay amount corresponding to the time required for the distance calculation is added to the color image, so that the output timing of the color image signal and the distance image signal can be synchronized.

  Furthermore, it is desirable that the processing for calculating the distance video signal is performed with an accuracy corresponding to the number of gradation bits of the camera-captured video. In the above formulas 1 and 2, since the division process is performed, a rounding error occurs. However, the calculation process is performed with an accuracy according to the number of gradation bits of the output video signal of the camera, thereby minimizing the influence of the rounding error. It is possible to perform a good distance detection.

  As described above, according to the present invention, the distance between the camera and the subject is detected in real time, and the calculation process is simplified, so that the distance detection can be speeded up and the influence of external light can be reduced. Since it can be eliminated and a key signal can be generated, no special equipment for image synthesis is required, and thus image processing can be performed in real time.

  Embodiments of the present invention will be described below with reference to the drawings.

  A distance detection apparatus 1 according to the present invention is, for example, shown in FIG. A distance detection camera 2 used in the distance detection apparatus 1 includes a light emitting unit 3 that irradiates a subject with intensity-modulated near-infrared light, and an image intensifier that has a high-speed shutter function and performs short-time imaging. And an imaging unit 4 having a CCD camera for inputting an optical image of the image intensifier, and a control unit unit 5 for controlling intensity modulation of the light emitting unit 3 and outputting a video signal from the imaging unit 4 as a digital signal. And at least.

For example, when the light emitting unit 3 acquires the first video signal V1 ′ and the second video signal V2 ′, as shown in FIG. 2, for example, the function f ₁ Light is emitted so as to change at (t), and then light is emitted so as to change at f ₂ (t), for example, in the direction in which the light intensity gradually decreases. Then, the subject when the light emitting unit 3 changes at f ₁ (t) is photographed by the imaging unit 4 as the first video signal V1 ′, and the light emitting unit 3 changes at f ₂ (t). A subject is photographed by the imaging unit 4 to be a second video signal V2 ′.

  When the signals from the distance detection camera 2 are only the first and second video signals V1 ′ and V2 ′, the two signals from the distance detection camera 2 (first and second video signals V1 ′). , V2 ′) are stored once in the memories M1 and M2, respectively, and after being called up, they are set up by 0 to 10% in the setup 9 and are output as calculation video signals V1 and V2, respectively. On the other hand, the calculation video signals V1 and V2 are subjected to angle-of-view (4: 3) conversion in the block 10 and then D / A converted in the block 11 and output as monitor video signals S1 and S2. is there.

  On the other hand, the calculation video signals V <b> 1 and V <b> 2 are input to the distance video calculation unit 20. The distance image calculation unit 20 is, for example, as shown in FIG.

The first calculation video signal V1 input to the distance video calculation unit 20 is converted into a predetermined function (first calculation function) F1 (V1) in a block 21. The function F1 (V1) is specifically f ₁ ⁻¹ (V1). Similarly, the second calculation video signal V2 is converted into a predetermined function (second calculation function) F2 (V2) in the block 22. This function F2 (V2) is specifically f ₂ ⁻¹ (V2).

  Then, the first and second arithmetic video functions F1 (V1) and F2 (V2) are subtracted in the block 23 and added in the block 24, and F1 (V1) −F2 (V2) and F1 are respectively obtained. (V1) + F2 (V2) is obtained and divided at block 25 to obtain {F1 (V1) -F2 (V2)} / {F1 (V1) + F2 (V2)}, which is then multiplied by a coefficient α Is multiplied. Further, 1 is added in block 27, and the result is halved to obtain the distance image d. As described above, the distance image calculation unit 20 performs the calculation according to the following Equation 1, and as a result, the distance image d is obtained.

The operation of the distance detection apparatus 1 according to the first embodiment will be described with reference to the flowchart shown in FIG. 4. The distance image calculation started from step 100 is performed by initializing each factor (n ← 1, Fl in step 110). ← 0) is performed, and it is determined in step 120 whether or not the first frame f (1) of the television video signal has been input. If not input (N), the process waits, and if input (Y ), The routine proceeds to step 130, where it is determined whether Fl is 1. In the first case, since Fl is 0, the routine proceeds to step 140, where the light emitting unit 3 is controlled by the function f ₁ (t), and the first arithmetic video signal V1 (1) is acquired. This is stored as M1 (1) in the memory at step 150, and 1 is set to Fl at step 152. This means that the first calculation video signal V1 (1) has been acquired in the first frame f (1) of the television video signal.

In the first case, the calculation result d (0) in step 210 is 0 because V2 (1) does not exist, d (0) is output in step 220, and 2 is set in n in step 230. Similarly, when the first frame f (2) is input, the routine proceeds to step 130, where it is determined whether or not Fl is 1. In step 152, since 1 is input to Fl, the routine proceeds to step 170. The light emitting unit 3 is controlled by the function f ₂ (t), and the second arithmetic video signal V2 (1) is acquired. This is stored as M2 (1) in the memory at step 180, and 0 is set to Fl at step 182. This means that the second arithmetic video signal V2 (1) is acquired in the second frame f (2) of the television video signal.

  As a result, as shown in the following formula, d (1) is calculated in step 210, d (1) is output in step 220, and 1 is added to n in step 230.

  In the next frame f (3), the first calculated video signal V1 (3) acquired at the time of this frame f (3) and the second acquired particularly of the previous frame f (2). In step 210, the distance video signal d (2) is calculated by the calculation video signal V2 (1) as shown in the following formula, d (2) is output in step 220, and 1 is set in n in step 230. Added.

  As a result, as shown in FIG. 8, the first calculation video signal V1 (n) and the second calculation video signal V2 (n) are alternately obtained for each frame f (n), and the frame f The first or second calculation video signal (V1 or V2) acquired in (n) and the second or first calculation video signal (V2) acquired in the previous frame f (n-1). Or the distance video signal d (n) is calculated for each frame by V1). In FIG. 8, ft represents 1/60 second.

  The distance video signal d acquired in this way is denoised by a median filter indicated by block 40. The distance video signal d output from the median filter 40 is subjected to angle-of-view (4: 3) signal conversion in the block 10 and as a monitor signal Da of the distance video signal d D / A converted in the block 11. Is output.

  On the other hand, the distance video signal d is subjected to angle-of-view (16: 9) signal conversion in a block 41 and up-converted to a high-definition TV signal in a block 42, while passing through a delay line 54 as a distance video signal d. It is output to the main line together with the color video signal. The distance video signal d is input to the position detection noise reduction device 50.

  This position detection noise reduction device 50 is, for example, as shown in FIG. The distance video signal d is input to a block 51 and compared with threshold values T1 and T2. When each pixel x of the distance video signal d is within the range set by the threshold values T1, T2 (T1 <T2) by this comparison (T1 <x <T2), the key signal “1” is output, When the threshold value is less than or equal to the threshold value T1 or greater than or equal to the threshold value T2, “0” is output. Thus, an image obtained by binarizing the calculated distance image at a certain threshold image level can be output.

  Further, the binarized image is output to the block 53 via the delay line 52, and the majority image is determined in the range of n × n pixels (for example, n = 1, 3, 5, and 7 can be switched). And outputs the result as a key signal. Thus, it is possible to perform filter processing for smoothing the boundary line of the binarized image.

  A signal from the color high-definition camera 13 is output to the color video main line CVS via the CCU 14, but is delayed by the time for which the distance video signal d is calculated. Delayed to synchronize with signal d. The block 12 is a synchronization signal output circuit that transmits an external synchronization signal to the CCU 14 and the control unit 5.

  Further, as shown in FIG. 3, in the distance calculation block 20, the added F1 (V1) + F2 (V2) is compared with a predetermined value H (0 to 20%) in the block 28. When F1 (V1) + F2 (V2) is low, the switch 30 is operated, the switch 2 is switched from the terminal 32 to the terminal 31, and d = 0 is output from the block 29. As a result, when the distance signal level is low, the noise increases rapidly, so the distance signal is forcibly set to 0 to suppress the increase in noise.

As shown in FIG. 6, in the distance image calculation according to the second embodiment, n is set to 1 in step 110, and it is determined in step 120 whether or not the first frame f (1) of the television image signal is input. Control is suspended until it is determined that the frame f (1) has been input. If the frame f (1) has been input (Y), the process proceeds to step 140. In step 140, the light emitting unit 3 is controlled by the function f ₁ (t), and the first calculation video signal V1 (1) is acquired. Then, the process proceeds to step 170, where the light emitting unit 3 is controlled by the function f ₂ (t) to obtain the second calculation video signal V2 (1), and is stored in the memory as M2 (1) in step 180. .

  As a result, as shown in the following equation, d (1) is calculated in the following equation in step 212, d (1) is output in step 220, and 1 is added to n in step 230.

  As described above, in the distance calculation shown in the second embodiment, as shown in FIG. 9, the first calculation video signal V1 and the second calculation video signal V2 are obtained for each frame, and based on this. Since the distance video signal d is calculated for each frame, the update speed of the distance video signal d can be improved as compared with the case of the first embodiment, and the shooting characteristics of the moving subject can be improved.

In the third embodiment, when the first video signal V1 ′, the second video signal V2 ′, and the third video signal V3 ′ are acquired, the light emitting unit 3 is first used as shown in FIG. To emit light such that it changes with a function f ₁ (t), for example, in a direction in which the luminous intensity gradually increases, and then emit light so as to change with, for example, f ₂ (t) in a direction in which the luminous intensity gradually decreases. No light is emitted for a predetermined period of time, which is a non-emission time (f ₀ ). Then, the subject when the light emitting unit 3 changes at f ₁ (t) is photographed by the imaging unit 4 as the first video signal V1 ′, and the light emitting unit 3 changes at f ₂ (t). The subject is photographed by the imaging unit 4 to be the second video signal V2 ′, and the subject when no light is emitted (f ₀ ) is photographed by the imaging unit 4 to be the third video signal V3 ′. Thus, the third video signal V3 ′ for acquiring the influence of external light is acquired.

  As shown in FIG. 1, three signals (first, second and third video signals V1 ′, V2 ′, V3 ′) from the distance detection camera 2 are stored in memories M1, M2, M3, respectively. Are each stored and called, and then set up by 0 to 10% in the set-up 9 and output as calculation video signals V1, V2 and V3. The calculation video signals V1, V2, and V3 are subjected to angle-of-view (4: 3) conversion in the block 10 and then D / A converted in the block 11 to be output as monitor video signals S1, S2, and S3. is there.

  Then, in the block 21 shown in FIG. 3, the first calculation video signal V1 and the third calculation video signal V3 for grasping the influence of the external light are excluded from the first calculation video signal V1. Similarly, the function F3 (V1-βV3) is obtained, and in the block 22, the influence of the external light is excluded from the second arithmetic video signal V2 and the third arithmetic video signal V3 for grasping the influence of the external light. A second calculation video function F4 (V2-βV3) is obtained, and calculation is performed in the same manner as in the first embodiment. In this case, the distance video signal d is calculated by the following formula 2. Note that β is a constant provided to properly reflect V3 in the distance video signal.

Further, as shown in FIG. 6, in the distance video calculation according to the third embodiment, n is set to 1 in step 110, and whether or not the first frame f (1) of the TV video signal is input in step 120 is determined. Control is suspended until it is determined that the frame f (1) is input, and when the frame f (1) is input (Y), the process proceeds to step 140 in the direction indicated by the dashed arrow. In step 140, the light emitting unit 3 is controlled by the function f ₁ (t) to obtain the first video signal V1 (1). In step 170, the light emitting unit 3 is controlled by the function f ₂ (t) to obtain the second video signal V2 (1), and is stored in the memory as M2 (1) in step 180. Further, the process proceeds to step 190, the light emission of the light emitting unit 3 is stopped, the third video signal V3 (1) is acquired, and is stored in the memory as M3 (1) in step 200.

  As a result, as shown in the following equation, d (1) is calculated by the following equation in step 215, d (1) is output in step 220, and 1 is added to n in step 230.

  Thus, in the distance calculation shown in the third embodiment, as shown in FIG. 10, the first calculation video signal V1, the second calculation video signal V2, and the third calculation video signal are shown for each frame. Since V3 is acquired and the distance video signal d is calculated for each frame based on this, the update speed of the distance video signal d can be improved and the shooting characteristics of the moving subject can be improved compared to the case of the first embodiment. is there. Further, since the external light can be excluded by acquiring the third video signal V3 ', it is possible to detect the distance more precisely.

  As described above, according to the present invention, since a distance image can be acquired simultaneously with the acquisition of a color image, the screen can be immediately cut out and the screen can be combined even during live broadcasting. This also makes it possible to synthesize CG and live-action video, which was difficult with the conventional chroma key method.

It is the block diagram which showed the whole structure of the distance detection apparatus. It is explanatory drawing which showed intensity | strength adjustment of the light emission part of Example 1 and 2. FIG. It is the block diagram which showed the structure of the distance image | video calculating part. It is the flowchart figure which showed the distance image calculation of Example 1. It is the block diagram which showed the structure of the position detection noise reduction apparatus. It is the flowchart figure which showed the distance image calculation of Example 2 and 3. FIG. 6 is an explanatory diagram showing intensity adjustment of a light emitting unit in Example 3. It is explanatory drawing which showed the distance image | video calculation pattern of Example 1. FIG. It is explanatory drawing which showed the distance image | video calculation pattern of Example 2. FIG. It is explanatory drawing which showed the distance image | video calculation pattern of Example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Distance detection apparatus 2 Camera for distance detection 3 Light emission part 4 Imaging part 5 Control unit 9 Setup 10 Angle-of-view signal conversion 11 D / A conversion 12 Synchronous signal output circuit 13 Hi-vision camera 14 CCU
DESCRIPTION OF SYMBOLS 15 Delay circuit 20 Distance image calculating part 40 Median filter 41 Angle-of-view signal conversion 42 Up-conversion 50 Position detection noise reduction apparatus

Claims (26)

Irradiating the subject with light whose intensity is modulated with the first characteristic, detecting a change in the reflected light from the subject, and obtaining a first video signal;
Irradiating the subject with light that is intensity-modulated with a second characteristic different from the first characteristic, detecting a change in reflected light from the subject, and obtaining a second video signal;
From the first video signal and the second video signal, a distance calculation calculation is performed according to the following formula 1, and a distance image between the subject and the distance is indicated by the brightness of the image,
A distance detection method characterized by outputting a distance image.

(Here, d is the distance, V1 is the first video signal, V2 is the second video signal, and α is a constant.)   2. The distance according to claim 1, wherein the first video signal and the second video signal are alternately acquired for each frame of a television video signal, and the distance video is sequentially updated in units of frames. Detection method.   3. The distance detection method according to claim 1, wherein the first video signal and the second video signal are stored in a memory and then read out for calculation. Irradiating the subject with light whose intensity is modulated with the first characteristic, detecting a change in the reflected light from the subject, and obtaining a first video signal;
Irradiating the subject with light that is intensity-modulated with a second characteristic different from the first characteristic, detecting a change in reflected light from the subject, and obtaining a second video signal;
Shoot the subject and detect the third video signal without illuminating the light,
From the first video signal, the second video signal, and the third video signal, a distance calculation calculation is performed according to Equation 2 below, and the distance between the subject is expressed as a distance video indicating the brightness of the image,
A distance detection method characterized by outputting a distance image.

(Where d is the distance, V1 is the first video signal, V2 is the second video signal, V3 is the third video signal, and α and β are constants.)   The first video signal, the second video signal, and the third video signal are acquired within a frame of a television video signal, and the distance video signal is updated and output at a video rate. Item 4. The distance detection method according to Item 3.   6. The distance detection method according to claim 4, wherein the first video signal, the second video signal, and the third video signal are stored in a memory and then read out for calculation.   The distance detection method according to any one of claims 1 to 6, wherein an image obtained by binarizing the calculated distance video signal at a predetermined threshold video level is output simultaneously.   Provided with a filter that smoothes the boundary line of the binarized image by performing majority decision on the image binarized at a predetermined threshold video level by taking the sum of the level values of a plurality of pixels around the pixel. The distance detection method according to claim 7, wherein:   The distance detection method according to claim 1, wherein the value of the constant α is varied in the mathematical expression.   10. The distance calculation result is set to 0 value when the sum of the first video signal and the second video signal is equal to or less than a predetermined value. Distance detection method.   The angle of view adjustment between a color image and a distance image from a camera that shoots a color image is performed by changing a region of effective pixels of an image sensor used for distance detection. The distance detection method as described in any one.   The distance according to any one of claims 1 to 11, wherein a delay circuit for adjusting a time lag caused by a calculation process between the color video signal and the distance video signal is provided in an output line of the color video signal. Detection method.   The distance detection method according to any one of claims 1 to 12, wherein the calculation process of the distance video signal is performed with an accuracy according to the number of gradation bits of the camera-captured video. First video signal detecting means for irradiating the subject with light whose intensity is modulated with the first characteristic and detecting a change in reflected light from the subject to be a first video signal:
Second video signal detecting means for irradiating the subject with light that is intensity-modulated with a second characteristic different from the first characteristic, and detecting a change in reflected light from the subject to obtain a second video signal:
Distance video calculation means for performing distance calculation calculation from the first video signal and the second video signal according to the following formula 1, and setting the distance between the subject and the distance video indicated by the brightness of the image; and distance A distance detection device comprising at least output means for outputting an image.

(Here, d is the distance, V1 is the first video signal, V2 is the second video signal, and α is a constant.)   15. The distance according to claim 14, wherein the first video signal and the second video signal are alternately acquired for each frame of the television video signal, and the distance video is sequentially updated in units of frames. Detection device.   16. The distance detecting apparatus according to claim 14, wherein the first video signal and the second video signal are stored in a memory and then read out for calculation. First video signal detecting means for irradiating the subject with light whose intensity is modulated with the first characteristic and detecting a change in reflected light from the subject to be a first video signal:
Second video signal detection means for irradiating the subject with light that is intensity-modulated with a second characteristic different from the first characteristic, and detecting a change in reflected light from the subject to obtain a second video signal:
Third video signal detecting means for photographing a subject and detecting a third video signal without irradiating light:
From the first video signal, the second video signal, and the third video signal, a distance calculation calculation is performed by the following formula 2, and a distance video in which the distance to the subject is indicated by the brightness of the image is obtained. A distance detection apparatus comprising at least a distance image calculation means; and an output means for outputting a distance image.

(Where d is the distance, V1 is the first video signal, V2 is the second video signal, V3 is the third video signal, and α and β are constants.)   The first video signal, the second video signal, and the third video signal are acquired within a frame of a television video signal, and the distance video signal is updated and output at a video rate. Item 18. The distance detection device according to Item 17.   The distance detecting device according to claim 17 or 18, wherein the first video signal, the second video signal, and the third video signal are stored in a memory and then read out for calculation.   20. The distance detecting device according to claim 14, wherein an image obtained by binarizing the calculated distance video signal with a predetermined video level is simultaneously output.   Provided with a filter that smoothes the boundary line of the binarized image by performing majority decision on the image binarized at a predetermined threshold video level by taking the sum of the level values of a plurality of pixels around the pixel. 21. The distance detecting device according to claim 20, wherein   The distance detection device according to claim 14, wherein the value of the constant α is variable in the mathematical expression.   23. The distance calculation result is set to 0 value when the sum of the first video signal and the second video signal is equal to or less than a predetermined value. Distance detection device.   The angle of view adjustment between a color image and a distance image from a camera that shoots a color image is performed by changing an effective pixel area of an image sensor used for distance detection. The distance detection apparatus as described in any one.   The distance according to any one of claims 14 to 24, wherein a delay circuit that adjusts a time lag caused by arithmetic processing between the color video signal and the distance video signal is provided in an output line of the color video signal. Detection device.   The distance detection device according to any one of claims 14 to 25, wherein the calculation processing of the distance video signal is calculated with an accuracy according to the number of gradation bits of the camera-captured video.

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