DE102011104216A1 - Method for three-dimensional acquisition of object to be utilized in entertainment field, involves creating and storing image data set comprising coding for images of objects, captured by optical acquisition unit at different polar angles - Google Patents

Abstract

The method involves positioning a three-dimensional object (9) at a set of polar angles with respect to an optical acquisition unit (3a) e.g. digital video camera. An image of the object at each polar angle is captured by the optical acquisition unit. The object is positioned at another set of polar angles with respect to the optical acquisition unit. An image of the object at each of the latter polar angles is captured by the optical acquisition unit. An image data set comprising coding for the images of the objects is created and stored. Independent claims are also included for the following: (1) a device for three-dimensional acquisition of an object (2) a computer program product for three-dimensional acquisition of objects.

Description

The present description relates to a method for the three-dimensional detection of objects, a device for the three-dimensional detection of objects and a computer program product for carrying out a method according to the invention.

Due to the technical developments in terms of the most realistic representation of objects in the field of entertainment, product presentation and industrial production, ie in the field of "virtual reality" and "augmented reality", there is a need for real objects for further processing and to digitize presentation such that these objects can be displayed in three dimensions. In order to generate a three-dimensional representation, a three-dimensional model of the object must generally be present.

It is an object of the invention to provide a method for detecting three-dimensional objects as well as a corresponding computer program product and a corresponding device in order to generate the necessary information for a three-dimensional representation in a simple and time-saving manner.

The object is solved by the features of the independent claims. Preferred embodiments are subject of the dependent claims.

Detection method according to one aspect

• – Bereitstellen zumindest einer optischen Erfassungseinrichtung;
• – Anordnen eines dreidimensionalen Objekts mit einer Längsachse Z, wobei das Objekt um vorbestimmte Polarwinkel mit Bezug zu der Längsachse Z zu der zumindest einen optischen Erfassungseinrichtung positionierbar ist;
• – Bestimmen von N Polarwinkeln α₁ bis α_N;
• – Bestimmen von N Polarwinkeln β₁ bis β_N, wobei gilt: β_i = α_i + δ für alle i ∊ [1...N] mit der Polarwinkeldifferenz δ;
• – Durchführen der folgenden Erfassungsschritte für jedes i ∊ [1...N]: – Positionieren des Objekts mit dem Polarwinkel α_i zu der zumindest einen optischen Erfassungseinrichtung – Erfassen eines i-ten ersten Bildes L_i des Objekts mit einer der zumindest einen optischen Erfassungseinrichtung und Speichern des i-ten ersten Bildes L_i; – Positionieren des Objekts mit dem Polarwinkel β_i zu der zumindest einen optischen Erfassungseinrichtung – Erfassen eines i-ten zweiten Bildes R_i des Objekts mit einer der zumindest einen optischen Erfassungseinrichtung und Speichern des erfaßten i-ten zweiten Bildes R_i;
• – Erstellen und Speichern eines Bilddatensatzes umfassend eine erste Kodierung der ersten Bilder L₁...L_N des Objekts und eine zweite Kodierung der zweiten Bilder R₁...R_N des Objekts.

One aspect of the present invention relates to a method for the three-dimensional detection of objects with the steps:

• - providing at least one optical detection device;
• Arranging a three-dimensional object having a longitudinal axis Z, the object being positionable by predetermined polar angles with respect to the longitudinal axis Z to the at least one optical detection device;
• Determining N polar angles α ₁ to α _N ;
• - Determining N polar angles β ₁ to β _N , where: β _i = α _i + δ for all i ε [1 ... N] with the polar angle difference δ;
• - Performing the following detection steps for each i ε [1 ... N]: - Positioning of the object with the polar angle α _i to the at least one optical detection means - detecting an i-th first image L _{i of} the object with one of the at least one optical Detecting means and storing the ith first image L _i ; - Positioning the object with the polar angle β _i to the at least one optical detection means - Detecting an ith second image R _{i of} the object with one of the at least one optical detection means and storing the detected i-th second image R _i ;
• - Creating and storing an image data set comprising a first coding of the first images L ₁ ... L _{N of} the object and a second coding of the second images R ₁ ... R _{N of} the object.

Advantageously, an improved quality of the image data set is achieved with the method according to the invention, so that an improved three-dimensional representation of the object is made possible. Further advantageously, the method is automatically carried out, so that the image data set in a simple and time-saving manner can be produced feasible.

The object is optically detected by means of at least one optical detection device, wherein a digital image of the object is generated during each detection. It is understood that the generated image is generated in computer readable form so that the image is processable by a computer implemented method of the invention. For example, the object can be detected by a digital still camera or by a digital video camera. The captured or generated image of the object can be stored as such or in a further processed form on a storage medium. Preferably, exactly one optical detection device can be provided for detecting the object. Alternatively, however, it is also possible to provide two, three, four, five, or more optical detection devices which preferably permit simultaneous detection of the object from different angles or perspectives.

The arrangement of the three-dimensional object relative to the at least one optical detection device can be clearly described by three variables: the polar angle, the azimuth angle and the distance between the object and the optical detection device. Assuming that the object stands or is arranged on a surface during the detection and thus its longitudinal axis Z is defined by the vertical or perpendicular, the polar angle describes the relative rotation of the object about the longitudinal axis Z or the relative rotation of the object at least one optical detection device about the longitudinal axis Z with respect to a predeterminable zero point within an equatorial plane, which is oriented perpendicular to the longitudinal axis. The polar angle has a value range from 0 ° to 360 °. The azimuth angle describes the angle that the connecting line between the object and the optical detection device with the Includes longitudinal axis Z. The azimuth angle has a value range of -90 ° to 90 °. The sign of the azimuth angle can be defined such that the optical detection device is positioned for azimuth angles less than 0 ° below the equatorial plane, ie shifted from the equatorial plane against the oriented longitudinal axis Z or in the direction of the center of the earth. Accordingly, the optical detection device for azimuth angle is greater than 0 ° then positioned above the equatorial plane.

Determining N polar angles α ₁ to α _N may include freely selecting the polar angles, where N is a natural number. Preferably, however, the value range of the polar angle is divided into equal intervals. For example, the polar angles may be determined by the relationship α _i = i × 360 ° / N for all i ε [1 ... N]. In this case, the value for N, for example, 2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 16, 18, 20, 24, 30, 36, 40, 45, 48, 60, 72, etc. be. More preferably, N is chosen such that α _{i is} an integer. More preferably, the difference of the polar angle α _i between adjacent positions for all selected polar angle α _{i is} equal. In other words, an equidistant division of the value range of the polar angle can take place.

For each predetermined polar angle α _i , a relative positioning of the object with one of the predetermined polar angles α _i to the at least one optical detection device takes place. In this case, the relative positioning can be effected by a displacement or rotation of the object and / or by a displacement or rotation of the at least one optical detection device. The positioning is preferably carried out by a drive motor. Advantageously, all predetermined and by the polar angle α _i defined positions are approached by the computer-controlled drive and the object can be optically detected in this position. More preferably, the azimuth angle for the predetermined polar angle α _{i is} constant, in particular equal to 0 °. For every i-th of the N positions of the object with the associated polar angle α _i , the optical detection and storage of an associated i-th first image L _{i of} the object takes place.

By choosing the polar angles α _i , associated further N polar angles β ₁ to β _{N are} defined by the relationship β _i = α _i + δ for all i ε [1 ... N]. In this case, the difference between two mutually associated polar angles is designated as the polar angle difference δ. The polar angle difference δ is preferably selected such that the Euclidean distance between the position of the optical detection device associated with the polar angle α _i and the position of the optical detection device associated with the polar angle β _i approximately corresponds to the distance d of the eyes or the pupillary distance of a human , The distance d may be about 50 mm to about 75 mm, in particular about 60 mm to about 65 mm. Depending on the distance R between the object and the optical detection device, the corresponding polar angle difference δ can be calculated by the relationship sin (δ / 2) = d / 2R, ie δ = 2arcsin (d / 2R). The polar angle difference δ is preferably between about 3 ° and about 20 °, more preferably between about 5 ° and about 10 °. Advantageously, a possible realistic stereoscopic effect is achieved in a viewer by this polar angle difference δ when an image data set acquired in this configuration is visualized at a later time. More preferably, the azimuth angle is identical for each position corresponding to two associated polar angles α _i and β _i . Particularly preferably, for all i [1... N] for the polar angles, β _i = α _i + δ = α _j with j ε [1... N]. In other words, the polar angle β _{i of} the i-th second image corresponds to the polar angle α _{j of} the j-th first image. Thus, particularly advantageously, the first and second images can be detected with exactly one optical detection device.

For each calculated polar angle β _i , a relative positioning of the object with one of the predetermined polar angles β _i to the at least one optical detection device takes place. As already described above, the relative positioning can take place by a displacement or rotation of the object and / or by a displacement or rotation of the at least one optical detection device. For each i-th of the N positions of the object with the associated polar angle β _i , the optical detection and storage of an associated i-th second image R _{i of} the object takes place.

The detected first and second images can be combined to form an image data set and stored. To the first images L ₁ ... L _N , which are preferably designed to be perceived in a later visualization by a left eye of the observer, of the second images R ₁ ... R _{N of} the object, which are preferably swept In order to be distinguished by a right eye of the viewer in a later visualization, the first and second images can be encoded accordingly.

The coding can be effected, for example, by storing the first and second images separately in the image data record, so that one of the first and one of the second images can be read out and visualized by a corresponding readout. In particular, each of the first images and each of the second images may be provided with a sequential number so that the associated first and second images may be identified.

More preferably, each of the first images may be filtered with a first filter as a preferred first encoding, and each of the second images may be filtered with a second filter as a preferred second encoding, whereby the two filtered images may be combined to form a resulting image. For example, the resulting image may have an RGB format (red-green-blue format) wherein a brightness of each first image is stored as a red value and a brightness of every other image is stored as a green value. The resulting composite image includes only red and green, each color representing a different angle of view.

Preferably, two optical detectors are provided which are positioned spaced from each other by the polar angle difference δ relative to the longitudinal axis Z of the object to simultaneously detect the i-th first image L _i and the ith second image R _{i of} the object. Advantageously, the time required for the detection of the object can thus be reduced.

Preferably, the distance between the two optical detection means can be kept constant by a rigid connection, whereby advantageously an improved constancy of the stereoscopic effect can be realized. Further advantageously, only one drive is necessary to position the two optical detection devices, wherein the positioning by the rigid connection takes place synchronously or together.

• – Erstellen eines ersten Tessellationsmodells anhand der ersten Bilder L₁...L_N des Objekts umfassend M_L erste Flächenelemente;
• – Erstellen eines ersten Texturmodells für alle M_L ersten Flächenelemente anhand der ersten Bilder L₁...L_N des Objekts;
• – Erstellen eines zweiten Tessellationsmodells anhand der zweiten Bilder R₁...R_N des Objekts umfassend M_R erste Flächenelemente;
• – Erstellen eines zweiten Texturmodells für alle M_R zweiten Flächenelemente anhand der zweiten Bilder R₁...R_N des Objekts.

Preferably, the method comprises creating the image data set, further comprising the following steps:

• - Creating a first Tessellationsmodells based on the first images L ₁ ... L _{N of} the object comprising M _L first surface elements;
• - Creating a first texture model for all M _L first surface elements based on the first images L ₁ ... L _{N of} the object;
• - Creating a second Tessellationsmodells based on the second images R ₁ ... R _{N of} the object comprising M _R first surface elements;
• - Creating a second texture model for all M _R second surface elements based on the second images R ₁ ... R _{N of} the object.

The first and the second tessellation model as well as the first and second texture model are expediently created in the same way, so that the representation of the first tessellation model and the first texture model will be described in detail below for both models.

The first tessellation model comprises an approximation of the surface of the detected or virtual object by a plurality of two-dimensional triangles, wherein the vertices of each triangle preferably lie exactly on the surface of the virtual object. To create the first tessellation model, it is preferable to perform the steps of cropping, shaping and surface smoothing.

Particularly preferably, an exemption of the detected object from the background also detected takes place. For this purpose, the background can be selected in an initial step of the method such that the background is designed monochrome or monochrome, wherein the hue (for example, represented in the RGB color space) does not find itself in the object to be detected. Such a method is known by the term "blue box", wherein a monochrome blue background is selected and the object positioned in front of or on the background does not have this blue tone.

By a logical XOR operation of a color coding (eg the RGB value) of each detected pixel of the first image with the color coding of the background color, a black-and-white representation results, in which, for example, white means the value "false" and black the Value "true" represents. In this black-and-white representation, all black areas belong to the detected object. In other words, a black silhouette of the object in the associated position results for each detected first image. If the areas of the silhouette are again occupied with the detected colors of the object, the result is a first image released from the background. The background can be replaced after being cleared by any background, such as a monochrome background or any scene.

The created silhouette of the first image or the silhouettes of the plurality of first images may be used to create a three-dimensional solid model of the detected object. The method known as the "silhouette method" utilizes the knowledge that the detected object is always within its silhouette. The silhouette generated from the i-th of the first images, together with the position of the optical detector associated with the i-th first image, defines a cone-shaped volume with the tip of the cone at the position of the optical detector and the outline of the silhouette the lateral surface defined by the irregular cone. Within the volume of the cone is the detected object. This applies to all cone-shaped volumes defined by the N first images and positions of the optical detection device. Therefore, the three-dimensional volume model of the detected object can be calculated by the intersection of all the cone-shaped volumes. The three-dimensional space is preferably subdivided into hexahedral volume elements (so-called voxels). An exemplary method for shaping forms then checks for all voxels whether a voxel lies at least partially or completely within all cone-shaped volumes and then marks this as belonging to the detected object. The result is a voxel-defined convex hull of the detected object.

The envelope of the detected object defined by the voxels comprises a step caused by the hexahedral shape of the voxels. In order to produce the smoothest possible surface of the detected object, surface smoothing is preferably carried out. This can be done by a tessellation (for example, a Delaunay triangulation) of the points lying on the surface by means of triangles. More preferably, the points on the surface of the detected object can be approximated, for example by a spline function, whereby a smoothing of the surface can be achieved. The result of the tessellation is a wireframe model of the detected object.

The triangular areas defined by the wireframe model can then be provided with textures taken from the acquired first images to produce a texture model. Preferably, the normal vector is calculated for each triangular area and the position of the optical detection device is determined which has the smallest angular distance from this normal vector. The first image detected from this position of the optical detection device thus corresponds substantially to a plan view of the triangular surface. Furthermore, a section of this first image can be selected which corresponds in its extent to the triangular area in order to take over the texture of this section for this triangular area. Preferably, the texture from the section of the first image can be adapted by interpolation or Kriging to a different geometry of the triangular area. The texturing of the triangular surfaces of the tessellation model or of the wireframe model advantageously produces a realistic three-dimensional representation or visualization of the object.

It is understood that with the aid of the tessellation models and the texture models also positions of the object can be generated by interpolation, which was not approached during the detection of the object by the at least one optical detection device. However, since the interpolation could affect the image quality, it is preferable to optically detect as many positions as possible. By independently providing the optically captured images of the object to a viewer's left and right eyes in an image data set, the quality of the visualization is advantageously increased. However, it is understood that the creation of the tessellation models and the texture models is not necessary, since the optically captured images as such or after performing the exemption can already be used for three-dimensional visualization.

Preferably, the method comprises the further step:
Representing the image data set by means of an output device, wherein an i-tes of the first images L _i is detectable only from the left eye of a viewer and wherein an associated i-tes the second images R _i is detectable only from the right eye of the viewer.

The representation of the image data record by means of the output device can be carried out simultaneously with the creation of the image data record or later on the basis of a stored image data record. The output device may comprise, for example, at least one screen or at least one projector.

For example, color coding or polarization coding of the first images L _i and the second images R _i can take place, the viewer wearing a corresponding device (3D glasses) in front of his eyes so that the first images L _{i can} only be detected by the left eye of the observer and the second images R _{i can} only be detected by the right eye of the observer. Such 3D glasses can be designed, for example, to position a red foil in front of the left eye and a green foil in front of the right eye.

In order to enable a three-dimensional visualization in color, the 3D glasses, for example, for the left and right eye slides or have lenses with different polarization properties. Accordingly, the screen or the projector must display the first images with a correspondingly different polarization of the light than the second images.

Further, color coding may also be performed so that the wavelength ranges of the blue, green and red light are respectively divided so that each region of the blue, green and red light is assigned to the left eye which is different from the area of blue, green and red respectively. green and red light, which is assigned to the right eye. This preferred method is also known as "interference filter technology". For example, the primary colors of the first images may be represented by the following wavelengths: red about 629 nm, green about 532 nm, blue about 446 nm. Of these, the fundamental colors of the second images may differ with the following wavelengths red about 615 nm, green about 518 nm, about blue 432 nm. The assignment of the first images for the left eye and the second images for the right eye is carried out with a 3D glasses, which has selective interference filters for the left and right eye filters out the corresponding wavelength triple.

More preferably, the output device can comprise exactly two screens or projectors, one of which is assigned to the left eye of the observer and the other of the two to the right eye. Thus, for example, a 3D glasses two projectors or screens include and corresponding eyepieces so that the viewer the first images is projected directly onto the retina of the left eye and the second images corresponding to the right eye.

More preferably, an interactive representation of the image data set, so that the viewer via an interface (for example, a mouse, a trackball, a touchpad, a keyboard, a touch screen, etc.) can select which associated pair of the first and second images is displayed. Advantageously, the viewer can rotate and move the three-dimensionally visualized object as desired. Particularly preferably, the image data set can be displayed as a three-dimensional film, in particular if the object has been detected by means of at least one video camera as an optical detection device.

• – Bestimmen von M Azimutwinkeln θ₁ bis θ_M;
• – Durchführen der N Erfassungsschritte für jedes j ∊ [1...M] mit den Schritten – Positionieren des Objekts mit dem Azimutwinkel θ_j zu der zumindest einen optischen Erfassungseinrichtung; – Positionieren des Objekts mit dem Polarwinkel α_i zu der zumindest einen optischen Erfassungseinrichtung – Erfassen eines ersten Bildes L_i,j des Objekts mit einer der zumindest einen optischen Erfassungseinrichtung und Speichern des ersten Bildes L_i,j; – Positionieren des Objekts mit dem Polarwinkel β_i zu der zumindest einen optischen Erfassungseinrichtung – Erfassen eines zweiten Bildes R_i,j des Objekts mit einer der zumindest einen optischen Erfassungseinrichtung und Speichern des erfaßten zweiten Bildes R_i,j;
• – Erstellen und Speichern eines Bilddatensatzes umfassend eine erste Kodierung der ersten Bilder L₁...L_N×M des Objekts und eine zweite Kodierung der zweiten Bilder R₁...R_N×M des Objekts.

Preferably, the method comprises the further step:

• Determining M azimuth angles θ ₁ to θ _M ;
• - performing the N detection steps for each j ε [1 ... M] with the steps of - positioning the object with the azimuth angle θ _j to the at least one optical detection device; - Positioning the object with the polar angle α _i to the at least one optical detection means - Detecting a first image L _{i, j of} the object with one of the at least one optical detection means and storing the first image L _{i, j} ; Positioning the object with the polar angle β _i to the at least one optical detection device, capturing a second image R _{i, j of} the object with one of the at least one optical detection device and storing the detected second image R _{i, j} ;
• - Creating and storing an image data set comprising a first coding of the first images L ₁ ... L _{N × M of} the object and a second coding of the second images R ₁ ... R _{N × M of} the object.

Determining M azimuth angles θ ₁ to θ _M may include freely selecting the azimuth angles, where M is a natural number. Preferably, however, the value range of the azimuth angle is divided into equally large intervals. For example, the azimuth angles may be determined by the relationship θ _j = j × 180 ° / M for all j ε [1 ... M]. The value for M may be, for example, 2, 3, 4, 5, 6, 9, 10, 15, 18, 20, 30, 45, 60, etc. More preferably, M is chosen such that θ _{j is} an integer. More preferably, the difference of the azimuth angle θ _i between adjacent positions is the same for all selected azimuth angles θ _i . In other words, an equidistant division of the value range of the azimuth angle can take place.

For each predetermined azimuth angle θ _j , relative positioning of the object at one of the predetermined azimuth angles θ _j and all of the predetermined polar angles α _i and β _i to the at least one optical detection device occurs. In other words, a surface detection of the outer shell of the object takes place. In this case, the relative positioning takes place in accordance with the predetermined azimuth angle θ _j expediently by a displacement or rotation of the at least one optical detection device, preferably by means of a motor drive. Advantageously, all predefined N × M positions defined by the polar angles α _i , β _i and azimuth angles θ _j can be approached by the computer-controlled drive and the object can be optically detected in these positions.

Device According to one aspect

• – zumindest eine optische Erfassungseinrichtung;
• – eine Objektaufnahme, durch welche ein dreidimensionales Objekt aufnehmbar ist,
• – einen Antrieb, wobei die Objektaufnahme mittels des Antriebs um eine Längsachse Z in einem vorbestimmbaren Polarwinkel relativ zu der zumindest einen optischen Erfassungseinrichtung positionierbar ist;
• – eine Steuereinrichtung, welche ausgelegt ist, um N Polarwinkeln α₁ bis α_N und N Polarwinkeln β₁ bis β_N bereitzustellen, wobei gilt: β_i = α_i + δ für alle i ∊ [1...N] mit der Polarwinkeldifferenz δ und wobei die Steuereinrichtung ausgelegt ist für jedes i ∊ [1...N] folgende Schritte durchzuführen: – Positionieren des Objekts mit dem Polarwinkel α_i zu der zumindest einen optischen Erfassungseinrichtung mittels des Antriebs; – Erfassen eines i-ten ersten Bildes L_i des Objekts mittels einer der zumindest einen optischen Erfassungseinrichtung und Speichern des i-ten ersten Bildes L_i in einem Datenspeicher; – Positionieren des Objekts mit dem Polarwinkel β_i zu der zumindest einen optischen Erfassungseinrichtung mittels des Antriebs; – Erfassen eines i-ten zweiten Bildes R_i des Objekts mit einer der zumindest einen optischen Erfassungseinrichtung und Speichern des erfaßten i-ten zweiten Bildes R_i;
• – eine Signalverarbeitungseinrichtung, welche ausgelegt ist, einen Bilddatensatzes umfassend eine erste Kodierung der ersten Bilder L₁...L_N des Objekts und eine zweite Kodierung der zweiten Bilder R₁...R_N des Objekts zu erstellen und zu speichern.

One aspect of the present invention relates to an apparatus for the three-dimensional detection of objects comprising:

• - At least one optical detection device;
• An object receptacle, by means of which a three-dimensional object can be accommodated,
• A drive, wherein the object receptacle can be positioned by means of the drive about a longitudinal axis Z in a predeterminable polar angle relative to the at least one optical detection device;
• A control device which is designed to provide N polar angles α ₁ to α _N and N polar angles β ₁ to β _N , where β _i = α _i + δ for all i ε [1 ... N] with the polar angle difference δ and wherein the control device is designed to carry out the following steps for each i ε [1 ... N]: - Positioning of the object with the polar angle α _i to the at least one optical detection means by means of the drive; Detecting an i-th first image L _{i of} the object by means of one of the at least one optical detection device and storing the i-th first image L _i in a data memory; - Positioning of the object with the polar angle β _i to the at least one optical detection means by means of the drive; Acquiring an i-th second image R _{i of} the object with one of the at least one optical detection means and storing the detected i-th second image R _i ;
• - A signal processing device which is designed to create an image data set comprising a first coding of the first images L ₁ ... L _{N of} the object and a second encoding of the second images R ₁ ... R _{N of} the object and to store.

Advantageously, the device can automatically detect an object three-dimensionally and, in particular, control the positioning of the object relative to the at least one optical detection device so that the object can be detected with little handling effort.

By the at least one optical detection device, a digital image of the object can be generated, which is then processable by a computer-implemented method. For this purpose, the optical detection device comprises at least one digital image sensor, such as a CCD sensor or a CMOS sensor, which may preferably be part of a digital still camera or a digital video camera. Particularly preferably, the captured images can be read out by the optical detection device by means of the "picture transfer protocol" (PTP).

The apparatus further preferably comprises at least one storage medium which can store the images captured by the optical detection means. Particularly preferably, the captured images are transmitted directly to the storage medium, in particular by means of the picture transfer protocol, and stored there, so that advantageously no storage medium has to be provided in the optical detection device. The storage medium may be, for example, a memory module (for example a RAM or EEPROM memory module), a floppy disk and / or a hard disk. The storage medium may in particular be part of a computer, which is connected to the at least one optical detection device via a "universal serial bus" (USB) connection, for example.

The object holder is designed to record a three-dimensional object at least in regions. For example, the object receptacle may have an area to which the object to be detected can be placed. More preferably, the surface may be concave in order to place the object in regions in the concave depression, whereby the object is fixed laterally. For example, a spherical object can not roll out of the concave trough.

For each predetermined polar angle α _i or β _i , a relative positioning of the object with one of the predetermined polar angles α _i or β _i to the at least one optical detection device takes place by means of the drive. The drive can be controlled or regulated by the control device. In other words, the drive can approach the predetermined position within a predeterminable tolerance. For this purpose, the drive may comprise, for example, a stepping motor.

The drive positions the object receptacle relative to the at least one optical detection device. In other words, the object holder can be moved by the drive. Alternatively or additionally, the optical detection device can be moved by means of the drive.

Preferably, the object receptacle has a turntable, which is rotatable about the longitudinal axis Z.

Preferably, the at least one optical detection device is attached to a detection device holder, which is pivotable about the longitudinal axis Z and / or which is pivotable along a vertical axis Z to the longitudinal axis Z pivot axis. As a result, advantageously different azimuth angles can be set.

Particularly preferably, the object holder has a monochrome coloring in order to advantageously facilitate the cropping of the object. More preferably, the device comprises at least one artificial light source to illuminate the object. In particular, the at least one artificial light source can be controlled by the control device. Thus, for example, the at least one artificial light source can only be lit when the object is detected by the at least one optical detection device. In particular, the artificial light source may be an electronic flash, which is expediently ignited merely for detecting the object.

The signal processing device can in particular form a unit with the control device and be part of a computer, for example. The signal processing device is designed to generate an image data set which comprises a first coding of the first images and a second coding of the second images. Particularly preferably, the signal processing device comprises integrated circuits (IC) or digital signal processors (DSP), which perform a corresponding coding of the images.

Preferably, the apparatus comprises two optical detectors positioned relative to the longitudinal axis Z spaced from each other by the polar angle difference δ, the i-th first image L _i and the ith second image R _{i of} the object being simultaneously detectable.

Preferably, the two optical detection means are rigidly connected to each other, so that in particular only one drive is necessary in the event that the optical detection means are moved for positioning. Particularly preferably, the distance between the optical detection devices, ie the distance between their optical axes when entering the detection devices, is approximately the distance d of the eyes or the pupillary distance of a person. The distance d is preferably about 50 mm to about 75 mm, in particular about 60 mm to about 65 mm.

Preferably, the signal processing device is designed to produce an image data record,
wherein by means of the signal processing device a first tessellation model can be generated on the basis of the first images L ₁ ... L _{N of} the object comprising M _L first surface elements,
wherein by means of the signal processing device, a first texture model for all M _L first surface elements based on the first images L ₁ ... L _{N of} the object is generated,
wherein by means of the signal processing means a second tessellation model based on the second images R ₁ ... R _{N of} the object comprising M _R first surface elements is generated and
wherein by means of the signal processing means a second texture model for all M _R second surface elements based on the second images R ₁ ... R _{N of} the object can be generated.

Computer program product according to one aspect

One aspect of the present invention relates to a computer program product embodied, in particular, as a signal and / or a data stream comprising computer readable instructions, which instructions perform a method of the invention when loaded and executed on a suitable computer system.

In other words, a computer program product is provided which comprises program parts for carrying out the method according to the invention or a preferred embodiment thereof. In other words, the method according to the invention can be a computer-implemented method. Further provided is a computer program which, when loaded on a computer, may perform the method according to the invention or a preferred embodiment. The computer may be part of the device according to the invention. For example, the computer may comprise the control device and / or the signal processing device. In other words, the control device and / or the signal processing device can be designed to load and execute computer-readable instructions, which in particular can be loaded by the computer program product according to the invention.

Furthermore, a computer-readable storage medium is provided on which such a computer program is stored. This storage medium may comprise, for example, a compact disc, a digital versatile disc, an SD card, a floppy disk, a hard disk or a memory module.

figure description

Hereinafter, preferred embodiments of the present invention will be described by way of example with reference to the accompanying drawings. Individual features of the preferred embodiments shown may be combined to other preferred embodiments. Show it:

1 a perspective view of a schematic structure of a preferred embodiment of an apparatus for three-dimensional detection of objects;

2 the structure of in 1 shown embodiment in a plan view;

3 the operating principle of the silhouette process;

4 the operating principle of the silhouette method with at least a first and at least a second optical detection device;

5 a flowchart of a preferred embodiment of the method for three-dimensional detection of objects;

6a - 6c Three exemplary tessellation models of an object with different resolutions.

The 1 and 2 show a schematic structure of a preferred embodiment of a device 1 for the three-dimensional capture of objects. The device 1 in this embodiment comprises two optical detectors 3a . 3b , which preferably by a common detector holder 5 are rigidly connected. Furthermore, the device comprises 1 an object shot 7 which is a three-dimensional object 9 can record. Preferably, the object holder 7 as a turntable 7 be formed, which by a drive 11 can be rotated about a longitudinal axis Z. As a result, a predeterminable polar angle α _{i is} relative between the first optical detection device 3a and the object 9 and a predeterminable polar angle β _i relative between the second optical detection means 3b and the object 9 adjustable.

The object shot 7 or the turntable 7 and an optional background element 8th can be designed monochrome or monochrome, wherein the hue is preferably not in the object to be detected 9 find yourself again. For example, turntables 7 or background element 8th be monochrome blue.

A control device 13 is designed to provide N polar angles α ₁ to α _N and N polar angles β ₁ to β _N , where β _i = α _i + δ for all i ε [1 ... N] with the polar angle difference δ. The polar angle difference δ is preferably selected such that the Euclidean distance between the first optical detection device 3a and the second optical detection device 3b preferably about 60 mm to about 65 mm, which corresponds approximately to the pupillary distance of a human. as a result, the polar angle difference is 8th preferably about 5 ° to about 10 °. Next is the positioning of the turntable 7 by the control device 13 performed, wherein the control device 13 the drive 11 so controls that with the drive 11 connected turntables 7 the desired N positions defined by the polar angles α _i are reached in succession. For this purpose, the drive preferably comprises a stepper motor.

The control device 13 further causes the detection of an i-th first image L _{i of} the object 9 by means of the first optical detection device 3a and acquiring an i-th second image R _{i of} the object 9 by means of the second optical detection device 3b as soon as the turntable 7 has reached the associated predetermined position. Preferably, the device comprises 1 at least one artificial light source 17 , which in particular by the control device 13 is controlled and is only lit when the object 9 is optically detected. The detected first image L _i and the second image R _{i of} the object 9 are then over the data lines 15a . 15b to the control device 13 transferred and there in a data store 19 stored readable.

A signal processing device 21 is adapted to generate from the detected first and second images an image data set which comprises a first coding of the first images L ₁ ... L _{N of} the object 9 and a second coding of the second images R ₁ ... R _{N of} the object 9 includes. The image data set may preferably also be in the data memory 19 be stored readable.

3 shows the functional principle of the silhouette process. Shown are exemplary five optical detectors 3a to 3e in different positions relative to the object 9 , It will be understood that alternatively, a single optical detector may be positioned corresponding to these five positions.

In order to generate a three-dimensional volume model of the detected object from a plurality of N captured images, the respective skins are generated for each of the N images as described above. The silhouette generated from the first image defines, together with the assigned position, the optical detection device 3a a cone-shaped volume 4a , wherein the tip of the cone at the position of the optical detection device 3a and the outline of the silhouette defines the lateral surface of the irregular cone. Accordingly, the silhouette of the second image together with the associated position defines the optical detection device 3b a similar cone-shaped volume 4b and so on.

The detected object 9 must be within the intersection 23 all conical volumes are located. The goodness of the adaptation of the intersection 23 to the actual outlines of the object 9 ie the maximum spatial resolution of the object 9 is determined among other things by the number of positions to which the object 9 by one of the optical detectors 3a - 3e was detected. By selecting the size of the volume elements (voxels) 25 to subdivide the space, the actual resolution achieved can be reduced. An exemplary method for shaping forms checks for all voxels whether a voxel lies at least partially or completely within all cone-shaped volumes and then marks this voxel as the detected object 9 properly. The resulting convex hull 27 of the detected object 9 represented in the in 2 Case shown the actual shell of the object 9 only inadequate, resulting in a reduction of the voxels 25 is improvable.

4 shows the principle of operation of the silhouette method carried out with a device comprising five first optical detection devices 3a . 3c . 3e . 3g . 3i and five second optical detectors 3b . 3d . 3f . 3h . 3y having. The second optical detection devices 3b . 3d . 3f . 3h . 3y are each a first optical detection device 3a . 3c . 3e . 3g . 3i assigned, the angle 8th between two associated first and second detection means about an axis Z of the object 9 as a function of the distance R of the detection devices from the axis Z such it is chosen that the Euclidean distance between two associated first and second detection means is about 50 mm to about 80 mm. It is understood that, alternatively, a single optical detection device according to the in 4 ten positions shown can be positioned. Alternatively, a first optical detection device 3a and a second optical detection device 3b be coupled to each other by the relative positions shown to the object 9 take one after the other.

Capturing the object 9 is preferably carried out at the same time by the at least one first optical detection device 3a . 3c . 3e . 3g . 3i and the associated second optical detection device (s) 3b . 3d . 3f . 3h . 3y , It is understood that a plurality of optical detection means may be positioned equidistantly around a circumference around the object, each optical detection means serving as first and second optical detection means. For this purpose, the distance between two of the equidistantly positioned optical detection devices is preferably between about 50 mm to about 80 mm or more preferably between about 60 mm to about 65 mm.

The creation of a three-dimensional volume model of the detected object 9 takes place for by means of the first optical detection means 3a . 3c . 3e . 3g . 3i captured images like 3 explained. In addition, independently of this, the creation of a three-dimensional volume model of the detected object takes place 9 by means of the second optical detection means 3b . 3d . 3f . 3h . 3y captured images analogous to how 3 explained. This results in two independent volume models, which can form the basis of an image data set for visualizations comprising a first and second coding, wherein the provided for the left and right eye of the viewer visualizations or images or first and second coding can be separated from each other.

The 5 shows a flowchart of a preferred embodiment of the method for three-dimensional detection of objects. For the creation of the solid model by the silhouette method, it may be necessary to first perform a calibration step S1 for calibrating the apparatus in order to correlate the image position of an imaged dot within a captured image with the spatial position in the three spatial directions. For this purpose, in the calibration step S1, prior to taking an object, a known, measured calibration pattern, for example the one shown in FIG 5 shown grid pattern, taken by the object shot and detected in predetermined positions by means of the first and second optical detection means, wherein the positions associated with the first and second images are generated. From the known geometry of the calibration pattern and the associated detected first and second images, the required calibration parameters can be calculated in a calibration step S3. Advantageously, a calibration can be used to detect a variety of objects detected with a device having a consistent acquisition geometry. Alternatively, calibration points may be located on the object receptacle which are detected upon detection of the first and second images and allow correlation of positions in a captured image with spatial positions from each of the captured images.

The method for detecting a three-dimensional object to be performed after the calibration steps S1 and S3 comprises performing N-times detection steps S5, as described above for each of the N detection steps positioning the object with a predetermined polar angle α _i to the at least one optical detection means , detecting an i-th first image L _{i of} the object with one of the at least one optical detection device, storing the i-th first image L _i , positioning the object with a polar angle β _i to the at least one optical detection device, detection of an i-th second image R _{i of} the object with one of the at least one optical detection means and storing the detected i-th second image R _i .

Based on the detected first and second images, a first tessellation model can be created in a tessellation step S7 on the basis of the acquired first images, and a second tessellation model can be created on the basis of the second images. Each Tessellationsmodell includes the spatial coordinates of the detected object. In order to calculate these spatial coordinates, preferably the calibration parameters calculated in the calibration step S3 are used. The spatial coordinates of the object are combined into triangles in each of the tessellation models, which approximate or approximate the surface of the detected object. Is exemplary in the 6a - 6c presented three tessellation models of an object with different resolutions. It shows the 6a a tessellation model with 12954 triangles, the 6b a tessellation model with 1558 triangles and the 6c a tessellation model with 638 triangles.

Further with reference to 5 For example, in a texturing step S9, a first texture model and a second texture model can be calculated using the first and second tesselation models. To select the optimum first and second captured images needed for texturing, those in the calibration step may be used 53 calculated calibration parameters are used.

In a coding step S11, the first and second texture models can be stored coded in an image data record on a storage medium. In other words, the stored image data set comprises a first coding of the first images of the object and a second coding of the second images of the object.

LIST OF REFERENCE NUMBERS

1

Device for the three-dimensional detection of objects

3a, 3b

optical detection device

4a, b

cone-shaped volume

5

Detector holder

7

Object holder, turntable

8th

Background element

9

object

11

drive

13

control device

15a, b

data lines

17

light source

19

data storage

21

Signal processing device

23

intersection

25

voxel

Z

longitudinal axis

Claims (11)

Method for the three-dimensional detection of objects, comprising the steps of: - providing at least one optical detection device ( 3a . 3b ); Arranging a three-dimensional object ( 9 ) with a longitudinal axis (Z), wherein the object at predetermined polar angles with respect to the longitudinal axis (Z) to the at least one optical detection device ( 3a . 3b ) is positionable; Determining N polar angles α ₁ to α _N ; Determining N polar angles β ₁ to β _N , where: β _i = α _i + δ for all 1 ε [1 ... N] with the polar angle difference δ; - Performing the following detection steps for each i ε [1 ... N]: - Positioning of the object with the polar angle α _i to the at least one optical detection means - detecting an i-th first image L _{i of} the object with one of the at least one optical Detecting means and storing the ith first image L _i ; - Positioning the object with the polar angle β _i to the at least one optical detection means - Detecting an ith second image R _{i of} the object with one of the at least one optical detection means and storing the detected i-th second image R _i ; - Creating and storing an image data set comprising a first coding of the first images L ₁ ... L _{N of} the object and a second coding of the second images R ₁ ... R _{N of} the object. Method according to claim 1, wherein two optical detection devices ( 3a . 3b ) which are relative to the longitudinal axis (Z) of the object ( 9 ) are positioned at a distance from each other by the polar angle difference δ to simultaneously detect the i-th first image L _i and the i-th second image R _{i of} the object. The method of claim 1 or 2, wherein the creation of the image data set comprises the following steps: - creating a first Tessellationsmodell based on the first images L ₁ ... L _{N of} the object comprising M _L first surface elements; Creation of a first texture model for all M _L first surface elements on the basis of the first images L ₁ ... L _{N of} the object (FIG. 9 ); - Creating a second Tessellationsmodells based on the second images R ₁ ... R _{N of} the object comprising M _R first surface elements; Creation of a second texture model for all M _R second surface elements on the basis of the second images R ₁ ... R _{N of} the object (FIG. 9 ). Method according to one of the preceding claims, comprising the further step of: - displaying the image data record by means of an output device, wherein one of the first images L _i is detectable only by the left eye of a viewer and wherein an associated i-tes of the second images R _i only from the right eye of the viewer is detectable. Method according to one of the preceding claims, comprising the further step: - determining M azimuth angles θ ₁ to θ _M ; - performing the N acquisition steps for each j ε [1 ... M] with the steps - positioning the object ( 9 with the azimuth angle θ _j to the at least one optical detection device; - positioning the object ( 9 ) with the polar angle α _i to the at least one optical detection device - detecting a first image L _{i, j of} the object ( 9 ) with one of the at least one optical Detection device ( 3a . 3b ) and storing the first image L _{i, j} ; - positioning the object ( 9 ) with the polar angle β _i to the at least one optical detection device - detecting a second image R _{i, j of} the object ( 9 ) with one of the at least one optical detection device ( 3a . 3b ) and storing the captured second image - creating and storing an image data set comprising a first coding of the first images L ₁ ... L _{N × M of} the object ( 9 ) and a second coding of the second images R ₁ ... R _{N × M of} the object ( 9 ). Contraption ( 1 ) for the three-dimensional detection of objects comprising: - at least one optical detection device ( 3a . 3b ); - an object image ( 7 ), through which a three-dimensional object ( 9 ) is receivable, - a drive ( 11 ), wherein the object receptacle by means of the drive about a longitudinal axis (Z) in a predeterminable polar angle relative to the at least one optical detection device ( 3a . 3b ) is positionable; A control device ( 13 ) which is designed to provide N polar angles α _i to α _N and N polar angles β ₁ to β _N , where β _i = α _i + δ for old i ε [1 ... N] with the polar angle difference δ and the control device ( 13 ) is designed for each i ε [1 ... N] following steps: - Positioning of the object ( 9 ) with the polar angle α _i to the at least one optical detection device ( 3a . 3b ) by means of the drive ( 11 ); Acquiring an i-th first image L _{i of} the object ( 9 ) by means of one of the at least one optical detection device ( 3a . 3b ) and storing the i-th first image L _i in a data memory ( 19 ); - positioning the object ( 9 ) with the polar angle β _i to the at least one optical detection device ( 3a . 3b ) by means of the drive ( 11 ); Detecting an i-th second image R _{i of} the object ( 9 ) with one of the at least one optical detection device ( 3a . 3b ) and storing the detected i-th second image R _i ; A signal processing device ( 21 ), which is designed to have an image data set comprising a first coding of the first images L ₁ ... L _{N of} the object ( 9 ) and a second coding of the second images R ₁ ... R _{N of} the object ( 9 ) to create and save. Apparatus according to claim 6, comprising two optical detection devices ( 3a . 3b ), which are relative to the longitudinal axis (Z) by the polar angle difference 8th are positioned at a distance from one another, the i-th first image L _i and the ith second image R _{i of} the object ( 9 ) are simultaneously detectable. Apparatus according to claim 6 or 7, wherein the signal processing device ( 21 ) is designed to create an image data record, wherein by means of the signal processing device ( 21 ) a first Tessellationsmodell based on the first images L ₁ ... L _{N of} the object ( 9 ) comprising M _L first surface elements is generated, wherein by means of the signal processing means ( 21 ) a first texture model for all M _L first surface elements based on the first images L ₁ ... L _{N of} the object ( 9 ) is generated, wherein by means of the signal processing means ( 21 ) a second tessellation model based on the second images R ₁ ... R _{N of} the object ( 9 ) comprising M _R first surface elements is producible and wherein by means of the signal processing device ( 21 ) a second texture model for all M _R second surface elements based on the second images R ₁ ... R _{N of} the object ( 9 ) is producible. Device according to one of claims 6 to 8, wherein the object receiving a turntable ( 7 ) which is rotatable about the longitudinal axis (Z). Device according to one of claims 6 to 8, wherein the at least one optical detection device ( 3a . 3b ) at a detector fixture ( 5 ), which is pivotable about the longitudinal axis (Z) and / or which is pivotable along a pivot axis perpendicular to the longitudinal axis (Z). Computer program product, in particular embodied as a signal and / or as a data stream comprising computer readable instructions, said instructions performing a method according to any one of claims 1 to 5 when loaded and executed on a suitable computer system.

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