JP2010157910A - Image display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image display device capable of more efficiently excluding unnecessary adjustment to visual point conversion to display an appropriate output image when a solid object exists on a road surface. <P>SOLUTION: The image display device (10) which performs the visual point conversion of an image around a vehicle obtained by an imaging means (12a) to display the image is provided with: a distance detection means (16a) for detecting a distance between the imaging means (12a) and an object; an angle calculation means (22) for calculating an angle formed of a line connecting a point on the object which is located in a perpendicular plane including an imaging axis of the imaging means (12a) and whose distance becomes a predetermined value (L<SB>0</SB>) with the imaging means (12a) to a perpendicular axis; a visual point conversion degree adjustment means (28) for adjusting the degree of visual point conversion based on the angle; and a solid object existence/nonexistence determination means (26) for determining the existence/nonexistence of the solid object based on a time variation of the angle wherein the visual point degree adjustment means (28) stops adjustment when it is determined that the solid object exists. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image display apparatus, and more particularly, to an image display apparatus that displays an image of a vehicle periphery obtained by an imaging unit by converting a viewpoint.

  Conventionally, a parking assist device for assisting parking by a driver is known. These devices generate an output image by converting the viewpoint of an input image obtained by imaging the periphery of the vehicle with a camera mounted on the vehicle, and display the output image to the driver. However, in these devices, when the angle of the camera with respect to the road surface (the angle of the imaging axis (optical axis) of the camera) changes due to road surface undulation and inclination, the loading of luggage on the vehicle, aging of the vehicle, etc. In some cases, viewpoint conversion to a desired output image cannot be performed, and as a result, an output image with a different scale or an output image with unnatural distortion correction may be generated.

  In order to solve this problem, Patent Document 1 uses a laser emitting device that emits a directional laser beam or a height sensor to measure the angle of the camera with respect to the road surface, and performs viewpoint conversion based on the measurement result. A technique for adjusting the degree and generating an output image corresponding to a change in the angle of the camera with respect to the road surface will be described.

  However, the apparatus described in Patent Document 1 is premised on the absence of a solid object such as a curb or a ring stop on the road surface. Therefore, when there is a three-dimensional object on the road surface, the degree of viewpoint conversion by misidentifying the surface of the three-dimensional object as a road surface even though the three-dimensional object does not actually affect the angle of the camera to the road surface. Therefore, an output image that gives a sense of incongruity to the driver is displayed.

On the other hand, the device described in Patent Document 2 specifies an area in image data where a solid object such as a curb or a ring stop exists based on two image data acquired continuously by the camera, and A point where the distance from the camera is a predetermined distance is detected using a laser radar corresponding to the camera, and an image corresponding to the detected point is included in an image region where the three-dimensional object exists. In this case, by recognizing that the point is not a road surface, an appropriate output image can be displayed without performing unnecessary adjustment in viewpoint conversion even when a three-dimensional object exists on the road surface.
JP 2003-274394 A JP 2008-34966 A

  However, since the apparatus described in Patent Document 2 needs to specify an area in image data where a three-dimensional object exists by performing image processing on at least two image data continuously acquired by a camera, the processing load is large. May adversely affect real-time performance.

  In view of this point, the present invention provides an image display device capable of displaying an appropriate output image by eliminating unnecessary adjustment for viewpoint conversion more efficiently when a three-dimensional object exists on the road surface. Objective.

  In order to achieve the above-mentioned object, an image display device according to a first invention is an image display device that displays an image of the periphery of a vehicle obtained by an imaging unit by converting the viewpoint, and includes the imaging unit and a subject. A line connecting the imaging means with a distance detecting means for detecting the distance between the imaging means and a point on the subject having a predetermined value within the vertical plane including the imaging axis of the imaging means with respect to the vertical axis An angle calculation unit that calculates an angle to be formed, a viewpoint conversion degree adjustment unit that adjusts a degree of viewpoint conversion based on the angle calculated by the angle calculation unit, and a three-dimensional image based on a change in angle calculated by the angle calculation unit. Three-dimensional object presence / absence determining means for determining the presence / absence of an object, wherein the viewpoint conversion adjusting means stops the adjustment when it is determined by the three-dimensional object presence / absence determining means that a three-dimensional object exists.

  By the above-described means, the present invention provides an image display device capable of displaying an appropriate output image by eliminating unnecessary adjustment for viewpoint conversion more efficiently when a three-dimensional object exists on the road surface. it can.

  Hereinafter, an image display device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a block diagram illustrating a configuration of an image display apparatus according to the embodiment. As shown in FIG. 1, an image display apparatus 10 according to the present embodiment includes a vehicle body 11, cameras (imaging means) 12a to 12d, an image input device 14, laser radars (distance detection means) 16a to 16d, and a radar signal input device. 18, input synchronization device 20, angle calculation device (angle calculation means) 22, initial setup information storage unit 24, three-dimensional object detection device (three-dimensional object presence / absence determination means) 26, viewpoint conversion device 28 (viewpoint conversion degree adjustment means), video A synthesizer 30, a video output device 32, and a display 34 are provided.

  The cameras 12a to 12d are monocular cameras using semiconductor elements such as CCDs or CMOSs, and are equipped with wide-angle lenses or fish-eye lenses. FIG. 2 is a perspective view showing an arrangement example of the camera according to the embodiment. Four cameras 12 a to 12 d equipped with fisheye lenses are respectively installed on the front, rear, left and right of the vehicle body 11. It shows that it can be confirmed by imaging the entire periphery of

  The image input device 14 is a device for acquiring camera images output from the cameras 12a to 12d, and preferably acquires images output from the cameras 12a to 12d while synchronizing at regular intervals. To do.

  The laser radars 16a to 16d are devices for detecting the distance between each of the cameras 12a to 12d and a subject (for example, a road surface). For example, the laser irradiation direction is periodically changed in the horizontal and vertical directions. Is a two-dimensional scanning laser radar that detects the distance to the subject within the imaging range of the cameras 12a to 12d. The laser radars 16a to 16d are arranged in association with the cameras 12a to 12d, respectively. The laser radars 16a to 16d may be one-dimensional scan laser radars.

  The radar signal input device 18 is a device for acquiring laser radar measurement signals (horizontal angle, vertical angle, and distance to the object) output from each of the laser radars 16a to 16d. A radar measurement signal output from each of the laser radars 16a to 16d is acquired asynchronously for each period.

  The input synchronization device 20 is a device that adjusts the input timing of signals from the image input device 14 and the radar signal input device 18. For example, at the time T, the image IM (T) and the laser radar measurement signal LM (T) are obtained. Similarly, at the time T + 1, the image IM (T + 1) and the laser radar measurement signal LM (T + 1) can be associated with each other.

The angle calculation device 22 uses a distance from each of the cameras 12a to 12d to the subject, which is calculated based on the outputs of the laser radars 16a to 16d, in a vertical plane including each imaging axis of the cameras 12a to 12d. There the angle which the distance connecting the respective center points of the point and the camera 12a~12d on the subject to be the predetermined value L ₀ line (hereinafter. to "viewpoint conversion reference lines") are formed with respect to the vertical axis (Hereinafter referred to as “viewpoint conversion reference angle”). Note that the angle calculation device 22 may calculate the depression angle of the viewpoint conversion reference line as the viewpoint conversion reference angle.

The predetermined value L ₀ is one of the initial setup information stored in the initial setup information storage unit 24, and the imaging axes (optical axes) from each of the cameras 12a to 12d to the road surface when the road surface is horizontal. ) The distance above.

The initial setup information storage unit 24 is a device for storing various kinds of information. Laser radar distance measurement initial information (a horizontal angle HA, a vertical angle VA when the road surface is horizontal, a distance to the object (described above) It corresponds to the predetermined value L _0. )), and the depression angle τ, the focal length f, and the installation height H of the cameras 12a to 12d measured when the vehicle is on a horizontal plane. The initial setup information storage unit 24 stores information regarding the relative positional relationship between each of the cameras 12a to 12d and each of the laser radars 16a to 16d.

  The three-dimensional object detection device 26 is a device that determines the presence or absence of a three-dimensional object based on the viewpoint conversion reference angle calculated by the angle calculation device 22. For example, the three-dimensional object detection device 26 is based on a time change of the viewpoint conversion reference angle calculated by the angle calculation device 22. Then, the presence or absence of a three-dimensional object in each camera image of the cameras 12a to 12d is determined.

  The viewpoint conversion device 28 maps the image acquired by the image input device 14 to a planar projection, a bowl-shaped model, or the like using, for example, a method described in JP-A-10-211849, JP-A-2003-274394, or the like. Then, the image is converted to a planar view image and prepared for video composition, and the cameras 12a to 12d capture images based on the depression angles τ of the cameras 12a to 12d stored in the initial setup information storage unit 24. The viewpoint of the captured camera image.

Further, the viewpoint conversion device 28, when the vehicle becomes a value distance on the imaging axis is not the predetermined value L ₀ from each to the road surface of the camera 12a~12d close to uphill or downhill, the angle calculating device The degree of viewpoint conversion is adjusted in accordance with the viewpoint conversion reference angle output by 22.

  Note that the viewpoint conversion device 28 determines the viewpoint conversion reference angle output by the angle calculation device 22 when the three-dimensional object detection device 26 determines that a three-dimensional object is present at the position where the laser beams of the laser radars 16a to 16d are irradiated. The adjustment of the degree of viewpoint conversion according to is canceled. This is to prevent the viewpoint conversion from being executed while misidentifying the surface of the three-dimensional object as a road surface.

  FIG. 3 is a diagram illustrating the perspective conversion principle according to the embodiment. In the perspective transformation shown in FIG. 3, the perspective transformation is performed when the position data of the road surface image is projected from the camera position R onto the screen plane P at the focal length f. Assume that the camera 12a is located at a point R (0, 0, H) on the Z axis and monitors an image on the road surface (xy coordinate plane) at a depression angle (looking-down angle) τ. In this case, as shown in the following equation (1), the two-dimensional coordinates (α, β) on the screen plane P (on the imaging screen) can be converted into coordinates (overhead view coordinates) on the road surface (reverse perspective conversion). .

つまり、上記式（１）を用いることにより、図４に示すように変換前イメージＩ１を変換後イメージＩ２へと変換でき、投影画像データ（俯瞰画像）を作成できる。

That is, by using the above formula (1), the pre-conversion image I1 can be converted into the post-conversion image I2 as shown in FIG. 4, and projection image data (overhead image) can be created.

  The video synthesizing apparatus 30 uses, for example, the cameras 12a to 12d adjusted by the viewpoint conversion apparatus 28 using a method described in Japanese Patent Application Laid-Open Nos. 2003-91720, 2002-166802, 3300334, and the like. Is a device that synthesizes four images from a single image.

  The video output device 32 is a device for converting the synthesized overhead view image into a video signal or the like and outputting it.

  The display 34 is for presenting the driver with a bird's-eye view image that has been subjected to luminance correction processing. In general, a liquid crystal monitor or a navigation monitor can be applied to the display 34.

  Next, the operation of the image display apparatus 10 according to the present embodiment will be described with reference to FIG. FIG. 5 is a flowchart illustrating the operation of the image display apparatus 10 according to the embodiment.

  First, the image display device 10 captures images from the cameras 12a to 12d into the system by the image input device 14 (step S1). The image display device 10 may capture an image at an arbitrary timing, but it is desirable to capture all the cameras 12a to 12d in synchronization, and the image capturing speed is close to real time. It is desirable that it is 30 fps or more.

  Further, the image display device 10 takes in the laser radar measurement signal from the laser radars 16a to 16d into the system by the radar signal input device 18 (step S2). The speed of capturing the signal is preferably 30 Hz or more in order to be close to real time.

  Thereafter, the image display device 10 causes the input synchronization device 20 to generate a trigger for acquiring the image captured in step S1 and the laser radar measurement signal captured in step S2, and performs information acquisition (step S3).

  Since the image display device 10 captures data into the system in parallel processing in steps S1 and S2, the information acquisition trigger is generated asynchronously separately from the processing in steps S1 and S2, and is close to real time. Data acquisition is performed at a frequency of 30 times / s or more.

  In the data acquisition, the latest information is acquired from the data captured in the processes of step S1 and step S2. The image display apparatus 10 performs the processing from step S1 to step S3 on all the sets of the cameras 12a to 12d and the laser radars 16a to 16d.

  Thereafter, the image display apparatus 10 performs viewpoint conversion of the image captured in step S1 by the viewpoint conversion apparatus 28 based on the initial setup information (for example, the depression angle τ) stored in the initial setup information storage unit 24. The image is projected onto a virtual horizontal plane (step S4).

  Thereafter, the image display device 10 uses the angle calculation device 22 to determine the viewpoint conversion reference angle for each set of the cameras 12a to 12d and the laser radars 16a to 16d based on the laser radar measurement signal acquired by the trigger of step S3. Is calculated.

  FIGS. 6 to 10 are diagrams illustrating a method in which the angle calculation device 22 calculates the viewpoint conversion reference angle, where an axis obtained by projecting the optical axis of the camera onto the road surface (horizontal plane) is a Y axis, and is orthogonal to the Y axis direction. The horizontal axis is defined as the X axis, and the axis orthogonal to the XY plane and passing through the center point of the camera is defined as the Z axis. When this is applied to a set of a camera 12a and a laser radar 16a attached to the front, a coordinate system as shown in FIGS. 6 and 7 is taken. The coordinate position relationship is the same for the sets of cameras 12b to 12d and laser radars 16b to 16d installed on the left side, right side, and rear side of the vehicle.

Laser radar distance measurement initial information stored in the initial setup information storage unit 24 (when the road surface is horizontal, the angle θ _HA on the XY plane formed by the viewpoint conversion reference line and the Y axis, the viewpoint conversion reference line and Z The angle θ _VA on the YZ plane formed by the axis and the distance L ₀ to the target are set in advance as θ _HA = 0 ° and θ _VA = 135 ° as shown in FIGS.

Figure 8 is a diagram showing the positional relationship between the laser radar 16a and the road surface in the case of uphill, the point s ₀ is located at the center point of the laser radar 16a stored in the initial setup information storage section 24 , point d ₀ is a point on the imaginary horizontal plane H of the laser beam of the laser radar 16a lands, the distance between the point s ₀ and the point d ₀ has a value L ₀ which is set in advance.

If a vehicle on the inclined is approaching as shown in Figure 8, the laser radar 16a receives the laser beam reflected at point d _0, not the point d _r, detects the distance L between the point s ₀ and the point d _r To do. Since the value of the distance L is different from the predetermined value L ₀ , the angle calculation means 22 scans the laser radar 16 a in the vehicle front-rear direction on the Y axis to derive a point c where the distance becomes the predetermined value L _0, and a predetermined viewpoint conversion reference angle theta (e.g., an initial set-up information storing unit stored in the 24 angle theta _VA, may be a depression angle tau.) calculating a deviation angle Δθ from. The deviation angle Δθ is an angle formed between the line segment s ₀ · d ₀ and the line segment s ₀ · c. For example, when the uphill extends from the origin O with the gradient Φ, It is represented by a function of L as shown in equation (2).

図９は、下り坂の場合における位置関係を示す図である。この場合、レーザレーダ１６ａの中心点ｓ_０とレーザレーダ１６ａで検出した点ｄ_ｒとの間の距離Ｌは、初期セットアップ情報格納部２４に格納されている所定値Ｌ_０（点ｓ_０と点ｄ_０との間の距離）よりも長い距離となる。角度算出装置２２は、上り坂の場合と同様に、レーザレーダ１６ａをＹ軸上で車両前後方向に走査して距離が所定値Ｌ_０となる点ｃを導き出し、所定の視点変換基準角度θからのズレ角Δθを算出する。ズレ角Δθは、線分ｓ_０・ｄ_０と線分ｓ_０・ｃとの間に形成される角度であり、例えば、下り坂が原点Ｏから勾配Φで始まる場合には、以下の式（３）のようなＬの関数で表わされる。

FIG. 9 is a diagram showing a positional relationship in the case of a downhill. In this case, the distance L, the initial setup information storage unit a predetermined value stored in 24 L _{0 (the} point s ₀ and the point between the center point s ₀ and the laser radar 16a d _r point detected by the laser radar 16a a longer distance than the distance) between the d _0. Angle calculating device 22, as in the case of uphill, the laser radar 16a distance scanned in the longitudinal direction of the vehicle is derived a point c becomes the predetermined value L ₀ on the Y-axis, from a predetermined viewpoint conversion reference angle θ The deviation angle Δθ is calculated. The deviation angle Δθ is an angle formed between the line segment s ₀ · d ₀ and the line segment s ₀ · c. For example, when the downhill starts from the origin O with the gradient Φ, the following equation ( It is expressed by a function of L like 3).

図１０は、路面上に立体物が存在する場合の位置関係を示す図である。この場合、レーザレーダ１６ａの中心点ｓ_０とレーザレーダ１６ａで検出した点ｄ_ｒとの間の距離Ｌは、初期セットアップ情報格納部２４に格納されている所定値Ｌ_０（点ｓ_０と点ｄ_０との間の距離）よりも短い距離となる。角度算出装置２２は、上り坂や下り坂の場合と同様に、レーザレーダ１６ａをＹ軸上で車両前後方向に走査して距離が所定値Ｌ_０となる点ｃを導き出し、所定の視点変換基準角度θからのズレ角Δθを算出する。ズレ角Δθは、線分ｓ_０・ｄ_０と線分ｓ_０・ｃとの間に形成される角度であり、上り坂や下り坂の場合と比べて大きな値となる。なお、距離Ｌが所定値Ｌ_０となる点が存在せず点ｃを導き出せない場合、角度算出装置２２は、ズレ角Δθを所定の最大値に設定する。

FIG. 10 is a diagram illustrating a positional relationship when a three-dimensional object exists on the road surface. In this case, the distance L, the initial setup information storage unit a predetermined value stored in 24 L _{0 (the} point s ₀ and the point between the center point s ₀ and the laser radar 16a d _r point detected by the laser radar 16a a shorter distance than the distance) between the d _0. Angle calculating device 22, as in the case of uphill and downhill, derive c that distance by scanning the laser radar 16a in the longitudinal direction of the vehicle on the Y axis is equal to a predetermined value L _0, predetermined viewpoint conversion reference A deviation angle Δθ from the angle θ is calculated. The deviation angle Δθ is an angle formed between the line segment s ₀ · d ₀ and the line segment s ₀ · c, and has a larger value than that of the uphill or downhill. If there is no point where the distance L is the predetermined value L ₀ and the point c cannot be derived, the angle calculation device 22 sets the deviation angle Δθ to a predetermined maximum value.

  Thereafter, the image display device 10 acquires the deviation angle Δθ from the predetermined viewpoint conversion reference angle θ calculated by the angle calculation device 22, and when the deviation angle Δθ is substantially equal to zero (YES in step S6), the road surface Shifts to step S9 without adjusting the viewpoint conversion degree.

  On the other hand, when the deviation angle Δθ is not zero (NO in step S6), the image display device 10 uses the three-dimensional object detection device 26 to determine whether a three-dimensional object exists in the camera image based on the magnitude of the deviation angle Δθ. It is determined whether or not (step S7).

  FIG. 11 is a diagram showing a temporal transition of the deviation angle Δθ, where the vertical axis is the deviation angle Δθ and the horizontal axis is the time t. FIG. 11 shows a transition of the deviation angle Δθ when the host vehicle approaches an uphill or a downhill by a broken line, and shows a transition of the deviation angle Δθ when the host vehicle approaches a three-dimensional object by a solid line.

  When the value of the deviation angle Δθ exceeds the threshold value TH, the image display device 10 determines that a three-dimensional object exists in the camera image (YES in step S7), and the three-dimensional object is displayed on the road surface. However, it is assumed that the road surface itself remains horizontal, and the process proceeds to step S9 without adjusting the viewpoint conversion degree.

  Further, the image display device 10 determines that the three-dimensional object is not present in the camera image when the value of the deviation angle Δθ is not zero but does not exceed the threshold value TH by the three-dimensional object detection device 26 (NO in step S7). ), The viewpoint conversion degree is adjusted based on the value of the deviation angle Δθ with respect to the predetermined viewpoint conversion reference angle θ calculated by the angle calculation device 22 assuming that the host vehicle is approaching the slope (step S8).

  Thereafter, the image display apparatus 10 uses the four images from the cameras 12a to 12d whose viewpoints are converted in step S4 by the video composition apparatus 30, or four from the cameras 12a to 12d whose degree of viewpoint conversion is adjusted in step S8. The sheets of images are synthesized using a technique as in the prior art (step S9). For image synthesis, for example, α blending is used to synthesize overlapping regions in front, rear, left, and right. In this embodiment, the front and rear images are combined with α value = 100%, and the left and right images are combined with α value = 0%.

  Thereafter, the image display device 10 converts the image synthesized in step S9 into a video signal or the like by the video output device 32, and outputs it to the display 34 (step S10).

  Thereafter, the image display device 10 repeats the steps from Step S1 to Step S10 until the display process is terminated (NO in Step S11), for example, by stopping the engine of the vehicle, and the display process is terminated. If it is determined that it should be performed (YES in step S11), the process is terminated.

  As described above, the image display apparatus 10 according to the embodiment determines whether or not a three-dimensional object exists on the road surface based on the deviation angle Δθ with respect to the predetermined viewpoint conversion reference angle θ, and the deviation angle Δθ is not zero. Only when it is determined that a three-dimensional object does not exist, adjustment for viewpoint conversion is executed, so that unnecessary adjustment for viewpoint conversion by misidentifying the surface of the three-dimensional object as a road surface is efficiently eliminated. Thus, an output image that has been appropriately converted in viewpoint can be displayed on the display 34.

  The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the above-described embodiment, the three-dimensional object detection device 26 adjusts the degree of viewpoint conversion based on the temporal transition of the deviation angle Δθ from the predetermined viewpoint conversion reference angle θ, but the viewpoint conversion reference angle itself (predetermined The degree of viewpoint conversion may be adjusted on the basis of the temporal transition of the difference angle Δθ added to or subtracted from the viewpoint conversion reference angle θ), or based on the temporal transition of the distance L detected by the laser radar. Then, the degree of viewpoint conversion may be adjusted.

  Further, the three-dimensional object detection device 26 may adjust the degree of viewpoint conversion based on the transition with respect to the movement distance of the host vehicle at the viewpoint conversion reference angle, the deviation angle Δθ, and the distance L. This is to cope with the case where the host vehicle moves intermittently while changing the speed.

  The three-dimensional object detection device 26 stops adjusting the degree of viewpoint conversion when a three-dimensional object exists on the road surface, but adjusts the degree of viewpoint conversion when a local dent or groove exists on the road surface. You may make it cancel.

It is a block diagram which shows the structure of the image display apparatus which concerns on embodiment. It is a perspective view which shows arrangement | positioning of the camera which concerns on embodiment. It is a figure which shows the perspective transformation principle which concerns on embodiment. It is a figure which shows the image before and after perspective transformation which concerns on embodiment. It is a flowchart which shows operation | movement of the image display apparatus which concerns on embodiment. It is the figure which shows the coordinate system of the camera which concerns on embodiment, and a laser radar (the 1). FIG. 6 is a diagram (part 2) illustrating a coordinate system of a camera and a laser radar according to the embodiment. It is a figure which shows the positional relationship between the laser radar and the road surface in the case of an uphill. It is a figure which shows the positional relationship between the laser radar and the road surface in the case of a downhill. It is a figure which shows the positional relationship between a laser radar and a road surface in case a solid object exists on a road surface. It is a figure which shows the time transition of the deviation | shift angle from a viewpoint conversion reference | standard angle.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image display apparatus 11 Car body 12a, 12b, 12c, 12d Camera 14 Image input apparatus 16a, 16b, 16c, 16d Laser radar 18 Radar signal input apparatus 20 Input synchronization apparatus 22 Angle calculation apparatus 24 Initial setup information storage part 26 Three-dimensional object detection Device 28 Viewpoint conversion device 30 Video composition device 32 Video output device 34 Display P Screen plane I1 Image before conversion I2 Image after conversion

Claims (1)

An image display device that displays an image of the surroundings of a vehicle obtained by an imaging means by converting the viewpoint,
Distance detecting means for detecting a distance between the imaging means and the subject;
An angle calculating means for calculating an angle formed with respect to the vertical axis by a line connecting a point on the subject having a predetermined value within the vertical plane including the imaging axis of the imaging means and the imaging means;
Viewpoint conversion degree adjusting means for adjusting the degree of viewpoint conversion based on the angle calculated by the angle calculating means;
Solid object presence / absence determining means for determining the presence or absence of a three-dimensional object based on a change in angle calculated by the angle calculating means;
The viewpoint conversion adjusting means stops the adjustment when the three-dimensional object existence determining means determines that a three-dimensional object exists;
An image display device characterized by that.

Images