GB2535742A

GB2535742A - A three dimensional scanning apparatus and method

Info

Publication number: GB2535742A
Application number: GB1503165.1A
Authority: GB
Inventors: Ritchie Charles; Crawford Scott; Buchanan Scott
Original assignee: Score Group Ltd
Current assignee: Score Group Ltd
Priority date: 2015-02-25
Filing date: 2015-02-25
Publication date: 2016-08-31
Also published as: GB201503165D0

Abstract

A 3D scanning apparatus 1 comprising an image capturing master module 10 and one or more image capturing slave modules 11 that are removably and adjustably placed at or about the master module 10 in a cooperative relationship to create a larger system. The apparatus may also include cameras 21 that can be moveably mounted on the controller 10 and the or each sub module 11. The scanner system may also include a control arrangement to control the cameras automatically. Each capturing unit 10, 11 may also include a light source for illuminating the object to be scanned, this may involve shining light away from the object and using a reflective panel to direct diffuse light towards the object. Also claimed is a related kit and method.

Description

A THREE DIMENSIONAL SCANNING APPARATUS AND METHOD

FIELD OF THE INVENTION

The invention relates to a three dimensional scanning apparatus for scanning three dimensional objects, such as, for example, but not limited thereto, a three dimensional photo booth, and a corresponding method of three dimensional scanning.

BACKGROUND OF THE INVENTION

A variety of 3D scanning solutions exist which use a number of differing techniques, each with its own advantages and disadvantages. Examples include, but are not limited to, structured light device, white light device and photogrammetry based systems.

For the application of capturing 3D models of humans, photogrammetry based systems are preferred. Unlike white or structured light systems, this removes the need for continuous bright light or multiple flashes which can upset children, pets and photo sensitive subjects.

In all types of system, the range in size, maximum height of a human and a requirement to capture a full 360 degree model, requires systems which contain multiple, often expensive sensors.

Alternatively, by moving the sensor around the subject's body, a lower number can be used. In such an arrangement, however, scanning solutions rely on heavy fixed installations which are required to remain in one location. Typically, these scanning solutions rotate the scanning devices and as such, are highly complex and are very sensitive to any changes in their operating environment.

They often require bright lighting, are designed for a fixed object size and are time consuming to install and calibrate.

Automated scanning technology is also troublesome as to capture a 360 degree model demands rotational movement around the subject. During this time, the subject being scanned must remain perfectly still for a series of smaller scans that will be overlaid later to produce the 3D image.

The footfall through the current scanners is greatly reduced due to the time taken to capture a 3D image, as multiple scans and repeated checks are required to ensure that the various scans are consistent with each other or repeated when scans fail due to movement. This has led to static and slow machines which are not suitable for use at short duration events, for example, weddings or music festivals.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided a three dimensional scanning apparatus comprising: an image capturing master module; and one or more image capturing slave modules removably and adjustably placed at or about the master module in a cooperative relationship with the master module to create a larger system.

Thus, the invention provides a three dimensional scanning apparatus which is modular, portable and useable within a variety of different locations.

It will be appreciated that the invention is not limited to a specific number of slave modules. The number of slave modules is dictated primarily by the intended use of the apparatus, the size range and/or complexity of an object to be scanned.

Advantageously, the number and positions of slave modules in the apparatus can be adjusted as required both during and after assembly of the apparatus.

Preferably, the master module and the or each slave module are generally upright in use.

Preferably, the master module is configured to work as a standalone unit.

Preferably, a plurality of slave modules is provided.

Preferably, in an assembled apparatus, the or each slave module is located spaced apart from the master module. Where a plurality of slave modules is provided, the slave modules are preferably spaced apart from each other.

Preferably, in an assembled apparatus, the master module and the or each slave module are arranged along and define a perimeter and a central scannable area inside the perimeter. In use, the object to be scanned is placed generally centrally in the scannable area.

The perimeter can be a closed perimeter or an open perimeter. The perimeter may be of any suitable shape, e.g. generally circular, generally elliptic or another shape which may be a complex or irregular shape. In one arrangement, the perimeter includes a curve having an inner concave side and an outer convex side. Preferably, in use the object is placed on the inner side of the curve. One or more slave modules may be provided inside the perimeter and/or at a location where view of the object to be scanned is restricted by other features of the object.

In a preferred arrangement, the master module and a plurality of slave modules are arranged along and define a perimeter so as to capture multiple images of an object around a 360 degree area around the object.

Each of the master module and the or each slave module may be of a generally elongated configuration. Each of the master module and the or each slave module may comprise a generally elongated panel. The master module preferably has a greater overall width than that of the or each slave module. Preferably, each of the master module and the or each slave module comprises one or more cameras.

Preferably, the number of slave modules in each apparatus is variable, depending on the intended use of the apparatus, the size range and/or complexity of the objects to be scanned. Preferably, the position of the or each slave module in the apparatus is adjustable. Preferably, the position of the or each slave module in the apparatus is independently adjustable.

Preferably, the number of cameras in each of the master module and the or each slave module is variable. Preferably, the or each camera is movably mounted on the master module. Preferably, the or each camera is movably mounted on and the or each slave module. Preferably, the position of the or each camera on the respective master module and/or the or each slave module is adjustable.

Preferably, the position of the or each camera on the respective master module and/or the or each slave module is independently adjustable. Preferably, the position of the or each camera on the respective master module and/or the or each slave module is automatically adjustable depending on the size, shape and position of the object to be scanned. Preferably, linear position of the or each camera on the respective master module and/or the or each slave module is adjustable.

Preferably, the linear position of the or each camera on the respective master module and/or the or each slave module is adjustable along one or more axes of the respective master module and/or the or each slave module. Preferably, the one or more axes include at least a longitudinal axis of the respective master module and/or the or each slave module. Preferably, angular position of the or each camera on the respective master module and/or the or each slave module is adjustable. Preferably, the angular position of the or each camera on the respective master module and/or the or each slave modules is adjustable about one or more axes of the respective master module and/or the or each slave module. Preferably, the or each camera is rotatably mounted on the respective master module and/or the or each slave module.

Preferably, one or more driving means, such as motors, may be provided for moving each camera.

Preferably, the apparatus comprises a control arrangement configured to control positions of the cameras of the master module and/or the or each slave module automatically, depending on the size, shape and position of the object to be scanned. Preferably, the control arrangement is configured to control the cameras of the master module and/or the or each slave module to capture images simultaneously. The control arrangement preferably comprises a computer.

Preferably, the apparatus comprises a system of continuous wiring connecting the master module and the or each slave module to the control arrangement and a storage device. Preferably, the master module and the or each slave module are each continuously wired to the control arrangement and the storage device via appropriately sized network hubs or switches. This provides for a dramatic increase in the speed of information transfer back to the control arrangement, with a corresponding decrease in the time taken to take each image and an increase in throughput. Thus, the apparatus is able to capture, store and process a plurality of images from a plurality of cameras in a relatively short period of time allowing for a rapid turnover of objects photographed.

Thus, the apparatus of the invention provides for more accurate, compared with existing devices, capturing of images of objects of varying sizes and heights while maximising image resolution for a given number of cameras and object size. In addition, by providing additional slave modules to cover areas where view is restricted by other features or shape of the object is complex, the apparatus of the invention allows irregular objects to be scanned. Adjustability the cameras ensures that the camera is positioned such that the object fills the image frame and maintains maximum resolution of the images on smaller objects. Since all the images are taken simultaneously there is no time for the object to move. This prevents any disjoint between images and avoids the need for a repeat scan This is particularly advantageous with children and pets.

Preferably, the master module comprises at least one light source for illuminating the object to be scanned. Preferably, the or each slave module comprises at least one light source for illuminating the object to be scanned.

Preferably, the light source is mounted on or adjacent to the or each camera of the respective master module and/or the or each slave module. Preferably, in the embodiment where the cameras are movably mounted on the respective master module and/or the or each slave module, the light source is mounted so as to move together with the respective camera. Preferably, the light source is mounted on the respective master module and/or the or each slave module so as to shine light in the direction away from the object to be scanned and the respective master module and/or the or each slave module comprises a reflective panel configured to diffuse the light from the respective light source and to direct the diffused light towards the object to be scanned. Preferably, each of the master module and the or each slave module comprises a front side, which in use faces the object to be scanned and a rear side, which in use faces away from the object to be scanned. Preferably, the light source is mounted on the rear side of respective master module and/or the or each slave module. Preferably, the reflective panel is provided at the rear side of the respective master module and/or the or each slave module. Preferably, one or more of the master module and the or each slave module comprise a light diffusing panel at the front side to further diffuse light and to minimise lens flares on an opposing camera. The light diffusing panel at the front side may be provided in the form of a frosted glass panel.

Mounting the light sources on movable cameras directs maximum light at the object to be scanned and thus maximises the brightness of the object and, as a result, enables faster shutter speeds and lower noise camera settings (for ISO compliance) to be used. Mounting the light sources on the rear sides of the modules while using reflective back panels enables diffusion of light and minimises the effects caused by other lighting sources on the opposite side of the object. This is assisted further by the inclusion of light diffusion panelling at the front.

In one arrangement, the apparatus is a photo booth having walls defined by the master module and the or each slave module.

According to a second aspect of the present invention, there is provided a method of scanning a three dimensional object, the method comprising the steps of: providing a three dimensional scanning apparatus comprising: an image capturing master module; and one or more image capturing slave modules removably and adjustably placing the or each slave module at or about the master module in a cooperative relationship with the master module to create a larger system.

Preferably, the method further includes the step of placing an object in a a central scannable area defined by the master module and the or each slave module and scanning the object with the master module and the or each slave module.

The method preferably includes providing a suitable number of slave modules depending on the intended use of the apparatus, the size range and/or complexity of the object to be scanned. Preferably, the method includes adjusting the position of the or each slave module in the apparatus. Preferably, the method includes adjusting the position of the or each slave module in the apparatus independently. Preferably, the method includes locating the or each slave module in a spaced apart relationship with the master module.

Preferably, the method includes arranging the master module and the or each slave module along a perimeter and defining a central scannable area inside the perimeter. Preferably, the method includes placing an object to be scanned generally centrally in the scannable area.

The method may include providing one or more slave modules inside the perimeter and/or at a location where view of the object to be scanned is restricted by other features of the object.

Preferably, the method includes arranging the master module and a plurality of slave modules along a perimeter so as to capture multiple images of an object around a 360 scannable area around the object.

Preferably, the method includes selecting a suitable number of slave modules depending on the intended use of the apparatus, the size range and/or complexity of an object to be scanned. Preferably, the method includes placing the slave modules spaced apart from each other.

Preferably, the method includes providing each of the master module and the or each slave module with one or more cameras.

Preferably, the method includes connecting the master module and the or each slave module to a control arrangement and a storage device via continuous wiring.

Preferably, the method includes varying the number of cameras in each of the master module depending on the intended use of the apparatus, the size range and/or complexity of the object to be scanned.

Preferably, the method includes movably mounting the or each camera is on the master module and/or the or each slave module. Preferably, the method includes adjusting position of the or each camera on the respective master module and/or the or each slave module depending on the intended use of the apparatus, the size range and/or complexity of the object to be scanned. Preferably, the method includes adjusting the position of the or each camera independently. Preferably, the method includes adjusting the position of the or each camera automatically depending on the size, shape and position of the object to be scanned.

Preferably, the method includes adjusting linear position of the or each camera. Preferably, the method includes adjusting linear position of the or each camera along one or more axes of the respective master module and/or the or each slave module. Preferably, the one or more axes include at least a longitudinal axis of the respective master module and/or the or each slave module. Preferably, the method includes adjusting angular position of the or each camera. Preferably, the method includes adjusting angular position of the or each camera about one or more axes of the respective master module and/or the or each slave module. Preferably, the method includes rotatably mounting the or each camera on the respective master module and/or the or each slave module.

Preferably, the method comprises using a control arrangement to control positions of the cameras of the master module and/or the or each slave module automatically, depending on the size, shape and position of the object to be scanned.

Preferably, the method comprises capturing a plurality of images of the object being scanned simultaneously. Preferably, the method comprises capturing all the images of the object being scanned simultaneously. Preferably, the method comprises using a control arrangement to control the cameras of the master module and/or the or each slave module to capture the images of the object being scanned simultaneously.

Preferably, the method comprises providing the master module and/or the or each slave module with at least one light source for illuminating the object to be scanned. Preferably, the method comprises mounting the light source on or adjacent to the or each camera of the respective master module and/or the or each slave module. Preferably, where the cameras are movably mounted on the respective master module and/or the or each slave module, the method includes mounting the light source so as to move together with the respective camera. Preferably, the method comprises mounting the light source on the respective master module and/or the or each slave module so as to shine light in the direction away from the object to be scanned and providing the respective master module and/or the or each slave module with a reflective panel configured to diffuse the light from the respective light source and to direct the diffused light towards the object to be scanned. Preferably, the method comprises mounting the light source on a rear side of respective master module and/or the or each slave module. Preferably, the method comprises mounting the reflective panel at the rear side of the respective master module and/or the or each slave module. Preferably, the method comprises providing one or more of the master module and the or each slave module with a light diffusing panel at a front side of the respective master module and/or the or each slave module to further diffuse light and to minimise lens flares on an opposing camera.

In one arrangement, the method comprises forming a photo booth having walls defined by the master module and the or each slave module.

According to a third aspect of the present invention, there is provided a kit of parts for assembling a three dimensional scanning apparatus comprising: an image capturing master module; and one or more image capturing slave modules removably and adjustably placeable at or about the master module in a cooperative relationship with the master module to create a larger system.

All essential, preferred or optional features or steps of one of the first, second or third aspect of the invention can be provided in conjunction with the features of the other of the first, second or third aspect of the invention and vice versa.

The invention provides a three dimensional scanning apparatus and method as defined in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention are described hereinafter with reference to the accompanying drawings in which: Figure la is a perspective view of an apparatus in accordance with the invention in accordance with one configuration; Figure 2 is a plan view of the apparatus of Figure 1; Figure 3 is a perspective view of an apparatus in accordance with the invention in accordance with another configuration; Figure 4 is a plan view of the apparatus of Figure 3; Figure 5 is a side view of a master module of the apparatuses of Figures 1 to 4; Figure 6 is a front view of the master module of Figure 5; Figure 7 is a perspective view of the master module of Figures 5 and 6; Figure 8 is a plan view of the master module of Figures 5 to 7; Figure 9 is an enlarged view of area N of Figure 5; Figure 10 is an enlarged view of area M of Figure 6; Figure 11 is an enlarged view of area L of Figure 7; Figure 12 is a side view of a slave module of the apparatuses of Figures 1 to 4; Figure 13 is a front view of the slave module of Figure 12; Figure 14 is a perspective view of the slave module of Figures 12 and 13; Figure 15 is an enlarged view of area W of Figure 13; Figure 16 is an enlarged view of area V of Figure 14; Figure 17 is an enlarged view of area U of Figure 15; Figure 18 is a schematic illustration of network equipment of the apparatuses of Figures 1 to 4; and Figure 19 is a schematic illustration of power supply of the master module of Figures 5 and 6 and the slave module of Figures 12 and 13; and Figure 20 is a schematic elevation of a scannable area of the apparatuses of Figures 1 to 4; Figures 21 to 24 are illustrations for Equations 1 to 4, respectively for calculating angular positions of cameras of the apparatuses of Figures 1 to 4.

DETAILED DESCRIPTION OF THE INVENTION

Referring to Figures 1 to 25, an apparatus for three dimensional scanning and a corresponding method in accordance with the present invention will now be jointly described. The apparatus of the invention is indicated generally by reference numerals 1 in Figures 1 and 2 and 100 in Figures 3 and 4. The apparatuses 1 and 100 differ only their shapes in plan view and the number of slave modules employed in the apparatuses 1 and 100. Therefore, common features of apparatuses 1, 100 have been assigned common reference numerals and the description below of these common features is to be understood as the common description of both apparatuses 1 and 100, unless otherwise stated.

In the presently described embodiment, the apparatus 1, 100 is provided in the form of a photo booth, preferably, but not exclusively, a portable photo booth for taking 3D images of humans or animals. It will be appreciated that the invention is not limited to this particular form and purpose and other arrangements would be apparent to a person skilled in the art. Specifically, scale and specific configuration of the apparatus me vary depending the intended use of the apparatus, the size range and/or complexity of the objects to be scanned. Other fields of use the apparatus may include, but not limited thereto, the entertainment industry in the production of movies and video games. Other common applications of this technology include industrial design, orthotics and prosthetics, reverse engineering and prototyping, criminology, geology and paleontology, entertainment industry, reconstruction of objects of historical, cultural or other interest and general documentation.

Referring initially to Figures 1 to 17 the three dimensional scanning apparatus 1, 100 comprises an image capturing master module 10 and a plurality of image capturing slave modules 11 removably and adjustably placed about the master module 10 in a cooperative relationship with the master module 10 to create a larger system.

It will be appreciated that the invention is not limited to a specific number of slave modules 11. The number of slave modules 11 the position of the or each slave module 11 in the apparatus 1, 100 is dictated primarily by the intended use of the apparatus 1, 100, the size range and/or complexity of an object to be scanned.

The number and positions of the or each slave module 11 in the apparatus 1, 100 can be adjusted as required both during and after assembly of the apparatus 1, 100. The master module 10 and the slave modules 11 are arranged along and define a perimeter and a central scannable area 60 inside the perimeter so as to capture multiple images of an object (not shown in the drawings) around a 360 degree area around the object. The object is normally placed centrally in the scannable area 60.

In Figures 1 and 2, the master module 10 and the slave modules 11 are arranged to define a circle. In Figures 3 and 4, the master module 10 and the slave modules 11 are arranged to define a rod shape with rounded ends. In the assembled apparatuses 1, 100 the slave modules 11 are located spaced apart from the master module 10 and from each other.

It will be appreciated that in other variations, the perimeter defined by the master module 10 and the slave modules 11 can be a closed perimeter or an open perimeter. The perimeter may be of any suitable shape, e.g. generally circular, generally elliptic or another shape which may be a complex or irregular shape. The perimeter may include a curve having an inner concave side and an outer convex side wherein the object to be scanned is placed on the inner side of the curve. The modularity of apparatus 1, 100 allows for a variety of differing configurations.

Although not shown in the drawings, one or more slave modules 11 may be provided inside the perimeter and/or at a location where view of an object to be scanned is restricted by other features of the object.

The master module 10 and the slave modules 11 are of a generally elongated configuration and comprise respective generally elongated panels 101 and 111. One panel 111 is provided in each slave module 11 and three panels 101 are provided the master module 10. The panels 101 and 111 include respective top plates 17 and 32. In the presently described embodiment, the master module 10 has a greater overall width than that of the slave module 11. In use, the master module 10 and the slave modules 11 are positioned generally upright. Each of the master module 10 and slave module 11 comprises a front side 96, which in use faces the object to be scanned and a rear side 98, which in use faces away from the object to be scanned.

If required, the master module 10 can function as a standalone unit.

The master module 10 is affixed to the ground via a base plate 18. The slave module 11 is affixed to the ground via a base plate 33. The base plates 18, 33 can be made of metal, such as for example, steel, or plastic.

Each of the master module 10 and the slave modules 11 comprises several cameras 21. The master module 10 has twelve cameras 21, four cameras 21 per each panel 101. The slave module 11 has four cameras in its single panel 101.

The number of cameras 21 in each of the master module 10 and the slave module 11 can be varied if required to suit, for example, a particular size or shape of the object to be scanned. Each camera 21 is movably mounted on a respective threaded guide rod 16 provided in the respective master module 10 and slave module 11. The position of each camera 21 on the respective master module 10 and slave module 11 is independently adjustable. The position of each camera 21 on the respective master module 10 and slave module 11 is adjustable automatically depending on the size, shape and position of the object to be scanned. Vertical position, i.e. height, of each camera 21 on the respective master module 10 and slave module 11 is adjustable by mounting the camera to move along a longitudinal (vertical in use) axis X (see Figures 6, 11, 13 and 17) of the respective master module 10 and slave module 11. Angular position, i.e. rotation, of the or each camera 21 on the respective master module 10 and slave module 11 is adjustable by rotatably mounting the camera to rotate about two axes, the longitudinal axis X and a horizontal axis Z lying in a plane parallel to the panel 101, 111 (see Figures 6, 11, 13 and 17) of the respective master module 10 and slave module 11.

Referring to Figures 5 to 17, each camera 21 is mounted on the respective master module 10 and slave module 11 via a mounting bracket 70. Each mounting bracket 70 comprises a front part 19 and a back part 20 which are coupled together, for example by bolting, screwing, gluing or snap-fitting, around threaded guide rods 16. Each camera bracket 70 houses a threaded bar adapter 54 which closely couples with a thread of one of these threaded guide rods 16 such that rotating that threaded guide rod 16 causes the camera 21 attached to it via the threaded bar adapter to raise or lower. Each camera 21 is connected to a separate threaded guide rod 16 and therefore can be independently raised or lowered. Each threaded guide rod 16 is attached to a respective stepper motor 14 via a grub screw 52.

Each stepper motor 14 is in turn connected to a stepper motor bracket 13 on the base plate 18, 33. Each threaded guide rod 16 is rotatably mounted in the top plate 17, 32 via a respective bearing arrangement 26. It should be noted that belt driven or other alternatives may be used to adjust the height of the cameras 21 in a similar manner and the description given above does not intent to limit the mode of operation of the cameras 21 to this type of automation and the description of the threaded guide rod arrangement given. The stepper motors 14 are controlled by respective local controllers 49, 37 located on the base plates 18, 33 of the master module 10 and the slave module 11 within respective housings 81, 83.

Each camera 21 is provided with a pair of limit switches 25, an upper switch and a lower switch. The switches 25 are connected to the local controller 49, 37. The controller 49, 37 monitors and interrupts/stops the stepper motors 14 if a collision is detected with brackets 70 of the other cameras 21.

Each camera 21 is attached to a servo motor 51 allowing the camera 21 to be rotated about the vertical axis X and the horizontal axis Z. The servo motor 51 is in turn fixed to the front part 19 of the bracket 70 of the camera 21. The servo motor 51 is controlled by the local controller 49, 37.

The local controllers 49, 37 are also configured to issue commands to the cameras 21 to capture and save images locally or to network storage.

The local controllers 49, 37 form part of a control arrangement (not indicated by a reference numeral) of the apparatus 1, 100 configured to control positions of the cameras 21 automatically, depending on the size, shape and position of the object to be scanned. The control arrangement is also configured to control the cameras 21 to capture images simultaneously.

The control arrangement may comprise a central controller, typically a computer. The central controller may be located on or adjacent the master module 10.

The apparatus 1, 100 comprises a system of continuous wiring connecting the master module 10 and each slave module 11 to a central controller and a storage device via network hubs or switches. This provides for a dramatic increase in the speed of information transfer back to the controller, with a corresponding decrease in the time taken to take each image and an increase in throughput. Thus, the apparatus 1, 100 is able to capture, store and process a plurality of images from a plurality of cameras 21 in a relatively short period of time allowing for a rapid turnover of objects photographed.

Each camera 21 is connected to the local controller 49, 37 via a flexible cable (not shown). The controllers 49, 37 are in turn connected via respective cables 42 to the central controller via suitable high speed network cable (such as CATS/5E/6/7/8 or fibre optic or similar). The cables 42 may be connected to the central controller via an optional local network switch (not shown), which can be added to increase bandwidth. The cables 42 are preferably bundled cables carrying network communications and optionally power supply between the modules 10, 11 and the central controller.

The local controller 49, 37 includes a microprocessor (not shown), such as, for example, but not limited thereto, a Raspberry Pi TM and a separate motor control board (not shown), which in turn are connected to the stepper motors 14 and servos 51. The microprocessor and the motor control board are used to regulate the frequency of the stepper motors 14 and servos 51 with minimal interruption to the ongoing processes. It will be appreciated that various other local controllers 49, 37 can be used such as, but not limited thereto, Inte/TM, AMDTM or ARMTm processors. With reference to Figures 18 and 19, the master module 10 is also used to house an operator interface 85, optional local network control equipment 87 connected to main network control equipment 89 and network attached storage 91, all connected using via cables 42. The housings 81, 83 may also enclose network power distribution and converter equipment 77. The power distribution and converter equipment 77 may be configured to convert a standard 240V AC power supply to 5V Dc power to the local controllers 49, 37 and 12/24V DC to the stepper motors 14 and the servo motors 51. Optionally, power distribution equipment can be included in the master module 10. This allows for the central connection and control of slave module power. Where this option is chosen, a plurality of quick coupling sockets (not shown) can be provided at the master module 10 for allowing connection of a single cable carrying both network signals and power. The connector type used for this system is typically a D type twenty five pin connector (not shown). The connector provides three wires for power and sixteen wires for communications, grouped into two sets of four pair Ethernet type connections. Other connectors are available depending on the density of cameras 21 installed, with D type connectors continuing to one hundred or one hundred and four contacts. Alternatively, slave modules 11 can be powered separately via their own dedicated supplies. The choice will depend on the power available at the scanner operating location and is chosen as part of the system specification.

It will be appreciated that many other network and control equipment configurations are possible, any of which may be used to drive the motors 14, 51. This description is not intended to limit the choice of motors, networking equipment, controllers or cabling and associated connectors.

The cameras 21 may designed specifically for use with the local controller 49, 37. Combined, these form a lost cost, yet high performance image capture solution, while providing low level access to the sensor and the ability to programme the local controller 49, 37 to perform a combination of standard and customised digital camera functions and programmable processing and networking capabilities.

In addition the cameras 21 are quickly interchangeable and due to their low cost, can be used in high quantities at a reasonable cost, increasing the sensor count for the end user at any given price point. It will be appreciated that various other cameras can be used, including, but not limited thereto, webcams or digital camera packages.

Each of the master module 10 and slave modules 11 comprises respective light sources 24, 39 for illuminating the object to be scanned. Each light source 24, 39 is mounted on or adjacent to each camera 21 of the respective master module 10 and slave module 11. Each light source 24, 39 is mounted so as to move together with the respective camera 21. Each light source 24, 39 is mounted on the respective rear sides 98 of master module 10 and slave module 11 so as to shine light in the direction away from the object to be scanned. Each of the master module 10 and slave module 11 comprises a respective reflective panel 23, 38 configured to diffuse the light from the respective light source 24, 39 and to direct the diffused light towards the object to be scanned. Each reflective panel 23, 38 is provided at the rear side 98 of the respective master module 10 and slave module 11. The light sources 24, 39 may comprise LEDs. LEDs provide the advantages of lower power usage and are robust enough to endure the shocks entailed with moving the slave modules 11. The LEDs are connected to the power distribution equipment by cables 43, 50 Additionally, each of the master module 10 and slave modules 11 comprise a light diffusing panel 46, 47 at the front side 96 to further diffuse light and to minimise lens flares on an opposing camera 21. The light diffusing panel 46, 47 may be made from a suitable light dispersing material, for example, PerspexTM or frosted glass.

An example of arranging the master module 10 and the slave modules 11 in the apparatus 1, 100 and setting up cameras 21 will be described below. It will be appreciated that the following description is not intended to limit the configurations that can be used by the apparatus 1, 100 of the invention.

Arrangement of modules (Figures 1 to 4) In the presently described example, the master module 10 and slave modules 11 are mutually arranged such any area of the object to be captured must be visible from a minimum, but is not limited to, three cameras 21. Rotation and offset of the cameras 21 must be minimised to reduce the change in the objects appearance between the adjacent captured images. For master modules 10 and slave modules 11 placed in an inward facing curve as shown in Figures 1 to 4, typically, but not exclusively, a maximum rotation, i.e. angular offset, of 30 degrees should be allowed between two neighbouring modules, with smaller rotation producing better results. For a 360 degree enclosure, a minimum of twelve modules, one master module 10 and eleven slave modules 11 is optimal, but the invention is not limited thereto. This ensures that the rotation of the modules does not exceed 30 degrees. However, this assumes that the object to be photographed is placed centrally within the apparatus 1, 100. Higher or lower number of modules can also be utilised. The rotation r is calculated as: r = 360/number of modules or r = 360/ (no of slave modules + number of master modules). The layout and calculation are typically done at system setup with the cameras 21 moving only vertically between the scanning processes to adjust for height variables. A maximum object shape and size must be specified before arranging the modules.

Next, the minimum distance from the object is calculated based on the number of cameras, visible angles of view of the camera and the object size. At curved regions of the perimeter defined by the modules 10, 11, each single camera 21 is expected to capture a full object diameter in the horizontal plane. The minimum distance in this plane (horizontal) is calculated using the following equation:-Minimum distance for horizontal = (2"tan(CAMERA_Horizontal ANGLE OF VIEW*0.5)/object diameter) In the vertical plane, a minimum of two cameras 21 are expected to cover the full object height. The following equation is used to calculate the minimum distance in this plane: Distancefor vertical = ((2"tan(CAMERA_Ve rtical ANGLE OF VIEW*0.5)/(2"( object height/number of cameras))) Where the cameras 21 are positioned such that their planes of view are parallel, such as with adjacent modules 10, 11 at straight regions of the perimeter defined by the modules 10, 11 (Figures 3 and 4), an additional equation applies: Maximum Gap between modules = minimum distance for vertical plane * tan(horizontal angle of view /2).

This ensures each spot on the object is visible from at least two cameras.

Once the minimum and maximum distances required in all cases are known, a value between the two is selected when assembling/adjusting the apparatus 1, 100 for a specific maximum height.

Camera Height (Figure 20) By default and determined through experimentation, the height h1 of the uppermost camera 21 P1 is set to 20% above the height of the object, with the remaining cameras 21 P2, 21 P3 and 21 P4 spread equally over the height of the module. The main aim is to position each camera 21 so that it can clearly see the top of the object, while minimising the difference in angle of rotation between the adjacent cameras 21, thereby maximising the chance of a successful scan. In addition, this value can be adjusted to suit the application via the operator interface.

This allows the user to raise the cameras 21 to cope with object containing internal inclusions or obstructions.

In addition to capturing the same spot on an object from cameras 21 in adjacent modules 10, 11, several angles in the vertical plane are taken of the object as shown in Figure 20. This minimises the effect of blind spots caused by protruding and recessed areas. With reference to figure 20, the intention is to maximise the overlap of the visible area of the cameras (21 P1 to 21 P4) and therefore maximise the resolution of the captured images and subsequent 3D model; while also capturing the object from a raised position (such as at 21 P1 and 21 P2) as well as a lowered one (at 21 P3 and 21 P4) to create a minimum of one, but preferably several, stereo views per module 10, 11.

Furthermore, by moving the cameras 21 closer to an object and lowering the cameras 21 before scanning smaller objects, higher density information can be captured due to the increased number of cameras 21 covering any one point.

As such, the apparatus 1, 100 can be optimised for objects of varying height by allowing the positions of the cameras 21 to be adjusted to suit the application, either by changing minimum distance (dg) from the object to be scanned or adjusting heights h1 to h4 of the cameras 21 P1 to 21 P4.

Camera Angle (Figures 20 to 24) The minimum number of cameras 21 per module 10, 11 is two, however this requires that the upper camera 21 be positioned such that the field of view can see both points A (farthest uppermost point) and B (closest lowermost point) of the object, while the lower camera 21 must be able to see points B and C (closest uppermost point), both completely overlapping so as to capture each spot from two locations (or in stereo). This may require that the cameras 21 are moved away from the object and subsequently reduces the resolution of the captured images, when compared to a system with a higher numbers of cameras 21.

In order to demonstrate how the above principles are applied, the method used for determining the angle of the camera (ACV) relative to the horizontal plane for higher numbers of cameras 21, is outlined below with reference to Figures 20 to 24.

Although a module 10, 11 of four cameras 21 is shown in Figure 20, modules 10, 11 containing differing numbers can be produced using a similar approach to the one outlined below, including three, five, six and seven camera module varieties. Nevertheless, the principle that at least two of these cameras 21 should be able to see any point on the object, must be maintained.

Equation 1 Camera 21 P1 is positioned such that the top edge of the picture is level with the maximum required height, at the farthest point (point A) of the object scanning area. The position can be adjusted manually or utilising the equation: Require °. Ingle = 90 1:Pertkat -ha. + tan

where h1 is the height of camera 21 P1, h0 is the height of the object, dO is the diameter of the object and dg is the distance from the camera 21 P1 to the object.

Equation 2 Camera 21 P2 is positioned such that the bottom edge of the picture is level with the front of the base of the scanning area (point B). The position can be adjusted manually or utilising the equation:-vertical. angle of f.& Required ngase= 180 + tan where h2 is the height of camera 21 P2, dg is the diameter of the object and dg is the distance from the camera to the object.

Equation 3 Camera 21 P3 is positioned such that the top edge of the picture is level with the closest point of the top of the photo area (point C). The position can be adjusted manually or utilising the equation:- Fier vert e oft,iect.-where h3 is the height of camera 21 P3, h0 is the height of the object and dg is the distance from the camera to the object.

Equation 4 Camera 21 P4 is positioned such that the top edge of the picture is level with the closest point of the bottom of the scanning area (point B). The position can be adjusted manually or utilising the equation:-Required ngie = 180 vertical enigle o where h4 is the height of camera 21 P4 and dg is the distance from the camera to the object.

Module Automation The adjustment of the cameras height and angular positions can be either calculated using the equations above, or manually selected using the operator interface. A positioning option screen can be called on the interface, either by clicking/touching an icon or by typing a special code on the entry screen.

Under automatic operation, the operator enters an object height and diameter and the software then uses the equations above to calculate the minimum distance from the camera 21 and the required height and angle of each camera 21.

These values are stored for each module 10, 11 and camera 21 within a file held on the network attached storage. As the modules is powered up, or upon receipt of a special broadcast message, the network file is read and checked for the settings associated with it (using MAC address or similar unique identifier). If none exist, the current defaults are loaded from the network in the same way.

The data can be stored and retrieved in a number of ways and the following description is not intended to limit the ways in which this is implemented. The data can be stored in a text string which begins with the MAC address of the local controller 49, 37 connected to the height and position stepper motors 14 and servo motors 51. The next value indicates the number of cameras 21 connected to the motors 14, 51, followed by the height and angle setting for each. As the file is being read and data unpacked, starting with the lowest camera 21 on a module 10, 11, each in turn is sent to the bottom using stepper motors 14 driving the threaded guide rods 16. The limit switches 25 are connected to a digital input on the local controller 49, 37, which monitor and interrupt/stop the stepper motors 14 if a collision is detected. The limit switch 25 reading is compared to a mask to determine whether it is the expected limit, if not, an error is raised. If it is correct, a step counter is reset. This is repeated for each of the connected cameras 21 to zero the position counter subsequently used to track the camera position.

Next, starting with the top camera 21 P1, each in turn is sent to the top of the module 10, 11. Each module is stepped once and counter incremented. The limit switches 25 are then checked in a similar method as previously described to detect and determine whether the correct upper limit has been reached. The total number of steps for the known height is then logged and the height of each step calculated by dividing the known height of the module by the number of steps.

If the position data has been successfully read and no errors occur when zeroing the camera's 21 position and calculating the actual height of a step, the process continues and starting with the top camera 21 P1, each is stepped upwards in turn to its set height, while a signal is sent to a servo motor 51 to drive it to the required angle.

Each camera 21 can in turn be set in manual mode. Using the position options screen, the operator can select a checkbox which can be password protected. The height can then be adjusted manually. As the operator does so, the software checks that it does not conflict with the other cameras' 21 positions and raises an error if this is the case. Once it has been set, the network file is updated and a broadcast message sent to all local controllers 49, 37 to check and re-adjust their positions via the file.

The present invention provides a three dimensional scanning apparatus 1, 100 which is modular, portable and useable within a variety of different locations. Thus, the apparatus 1, 100 provides for more accurate, compared with existing devices, capturing of images of objects of varying sizes and heights while maximising image resolution for a given number of cameras and object size. In addition, by providing additional slave modules 11 to cover areas where view is restricted by other features or shape of the object is complex, the apparatus 1, 100 allows irregular objects to be scanned. Adjustability the cameras 21 ensures that the camera 21 is positioned such that the object fills the image frame and maintains maximum resolution of the images on smaller objects. Since all the images are taken simultaneously there is no time for the object to move. This prevents any disjoint between images and avoids the need for a repeat scan. This is particularly advantageous with children and pets.

Mounting the light sources 24, 39 on movable cameras 21 directs maximum light at the object to be scanned and thus maximises the brightness of the object and, as a result, enables faster shutter speeds and lower noise camera settings (for ISO compliance) to be used. Mounting the light sources 24, 39 on the rear sides 98 of the modules 10, 11 while using reflective back panels 23, 38 enables diffusion of light and minimises the effects caused by other lighting sources on the opposite side of the object. This is assisted further by the inclusion of light diffusion panelling 46, 47 at the front sides 96 of the modules 10, 11.

Modifications are possible within the scope of the invention, the invention being defined in the appended claims.

Claims

CLAIMS: 1. A three dimensional scanning apparatus comprising: an image capturing master module; and one or more image capturing slave modules removably and adjustably placed at or about the master module in a cooperative relationship with the master module to create a larger system.
2. An apparatus as claimed in claim 1, wherein the number and positions of slave modules in the apparatus are adjustable.
3. An apparatus as claimed in claim 1 or claim 2, wherein in an assembled apparatus the or each slave module is located spaced apart from the master module.
4. An apparatus as claimed in any preceding claim, wherein a plurality of slave modules is provided.
5. An apparatus as claimed in claim 4, wherein the slave modules are spaced apart from each other.
6. An apparatus as claimed in any preceding claim, wherein the master module and the or each slave module are arranged along and define a perimeter and a central scannable area inside the perimeter.
7. An apparatus as claimed in claim 6, wherein one or more additional slave modules may be provided inside the perimeter and/or at a location where view of an object to be scanned is restricted by other features of the object.
8. An apparatus as claimed in claim 6 or claim 7, wherein the master module and a plurality of slave modules are arranged along and define the perimeter so as to capture multiple images of an object around a 360 degree area around the object.
9. An apparatus as claimed in any preceding claim, wherein the number of slave modules in the apparatus is variable, depending on the intended use of the apparatus, the size range and/or complexity of objects to be scanned.
10. An apparatus as claimed in any preceding claim, wherein the position of the or each slave module in the assembled apparatus is adjustable.
11. An apparatus as claimed in any preceding claim, wherein the master module has a greater overall width than that of the or each slave module.
12. An apparatus as claimed in any preceding claim, wherein each of the master module and the or each slave module comprises one or more cameras.
13. An apparatus as claimed in claim 12, wherein the number of cameras in each of the master module and the or each slave module is variable.
14. An apparatus as claimed in claim 12 or claim 13, wherein the or each camera is movably mounted.
15. An apparatus as claimed in claim 14, wherein the position of the or each camera is adjustable.
16. An apparatus as claimed in claim 15, wherein the position of the or each camera is automatically adjustable based upon determination of the size, shape and position of an object to be scanned.
17. An apparatus as claimed in claim 15 or claim 16, wherein linear position of the or each camera is adjustable.
18. An apparatus as claimed in claim 17, wherein the linear position of the or each camera is adjustable along at least a longitudinal axis of the respective master module and/or the or each slave module.
19. An apparatus as claimed in any one of claims 15 to 18, wherein angular position of the or each camera is adjustable.
20. An apparatus as claimed in claim 19, wherein the or each camera is rotatably mounted.
21. An apparatus as claimed in any one of claims 14 to 20, wherein one or more driving means, such as motors, is provided for moving each camera.
22. An apparatus as claimed in any one of claims 15 to 21, wherein the apparatus comprises a control arrangement configured to control positions of the or each cameras automatically based upon determination of the size, shape and position of an object to be scanned.
23. An apparatus as claimed in claim 22, wherein the control arrangement is configured to control the cameras of the master module and/or the or each slave module to capture images simultaneously.
24. An apparatus as claimed in claim 22 or claim 23, wherein the control arrangement comprises a computer.
25. An apparatus as claimed in any one of claims 22 to 24, wherein the apparatus comprises a system of continuous wiring connecting the master module and the or each slave module to the control arrangement and a storage device.
26. An apparatus as claimed in any one of claims 12 to 25, wherein each of the master module and the or each slave module comprises at least one light source for illuminating the object to be scanned.
27. An apparatus as claimed in claim 26, wherein the light source is mounted on or adjacent to the or each camera.
28. An apparatus as claimed in claim 27 and any one of claims 14 to 20, wherein the light source is mounted so as to move together with the respective camera.
29. An apparatus as claimed in any one of claims 26 to 28, wherein the light source is mounted on the respective master module and/or the or each slave module so as to shine light in the direction away from the object to be scanned and the respective master module and/or the or each slave module comprises a reflective panel configured to diffuse the light from the respective light source and to direct the diffused light towards the object to be scanned.
30. An apparatus as claimed in claim 29, wherein each of the master module and the or each slave module comprises a front side, which in use faces the object to be scanned and a rear side, which in use faces away from the object to be scanned, wherein, the light source is mounted on the rear side of the respective master module and/or the or each slave module and the reflective panel is provided at the rear side of the respective master module and/or the or each slave module.
31. An apparatus as claimed in claim 30, wherein one or more of the master module and the or each slave module comprise a light diffusing panel at a front side of the respective master module and/or the or each slave module.
32. An apparatus as claimed in any preceding claim, wherein the apparatus is a photo booth having walls defined by the master module and the or each slave module.
33. A kit of parts for assembling a three dimensional scanning apparatus comprising: an image capturing master module; and one or more image capturing slave modules removably and adjustably placeable at or about the master module in a cooperative relationship with the master module to create a larger system.
34. A kit of parts as claimed in claim 33, wherein the apparatus is in accordance with any one of claims 1 to 32.
35. A method of scanning a three dimensional object, the method comprising the steps of: providing a three dimensional scanning apparatus comprising: an image capturing master module; and one or more image capturing slave modules; removably and adjustably placing the or each slave module at or about the master module in a cooperative relationship with the master module to create a larger system.
36. A method of claim 35, wherein the method further includes the step of placing an object in a central scannable area defined by the master module and the or each slave module and scanning the object with the master module and the or each slave module.
37. A method of claim 35 or claim 36, wherein the method includes providing a suitable number of slave modules depending on the intended use of the apparatus, the size range and/or complexity of the object to be scanned.
38. A method of any one of claims 35 to 37, wherein the method includes adjusting the position of the or each slave module in the apparatus.
39. A method of any one of claims 35 to 38, wherein the method includes locating the or each slave module in a spaced apart relationship with the master module.
40. A method of any one of claims 35 to 39, wherein the method includes arranging the master module and the or each slave module along a perimeter, defining a central scannable area inside the perimeter, and placing an object to be scanned generally centrally in the scannable area.
41. A method of claim 40, wherein the method includes providing one or more slave modules inside the perimeter and/or at a location where view of the object to be scanned is restricted by other features of the object.
42. A method of claim 40 or claim 41, wherein the method includes arranging the master module and a plurality of slave modules along a perimeter so as to capture multiple images of an object around a 360 scannable area around the object.
43. A method of any one of claims 35 to 42, wherein the method includes providing a plurality of slave modules.
44. A method of claim 43, wherein the method includes placing the slave modules spaced apart from each other.
45. A method of any one of claims 35 to 44, wherein the method includes providing each of the master module and the or each slave module with one or more cameras.
46. A method of claim 45, wherein the method includes varying the number of cameras in each of the master module depending on the intended use of the apparatus, the size range and/or complexity of the object to be scanned.
47. A method of claim 45 or claim 46, wherein the method includes movably mounting the or each camera is on the master module and/or the or each slave module.
48. A method of claim 47, wherein the method includes adjusting position of the or each camera on the respective master module and/or the or each slave module depending on the intended use of the apparatus, the size range and/or complexity of the object to be scanned.
49. A method of claim 48, wherein the method includes adjusting the position of the or each camera automatically depending on the size, shape and position of the object to be scanned.
50. A method of claim 48 or claim 49, wherein the method includes adjusting linear position of the or each camera.
51. A method of claim 50, wherein the method includes adjusting linear position of the or each camera along at least a longitudinal axis of the respective master module and/or the or each slave module.
52. A method of any one of claims 48 to 51, wherein the method includes adjusting angular position of the or each camera.
53. A method of claim 52, wherein the method includes rotatably mounting the or each camera on the respective master module and/or the or each slave module.
54. A method of any one of claims 48 to 53, wherein the method comprises using a control arrangement to control positions of the cameras of the master module and/or the or each slave module automatically depending on the size, shape and position of the object to be scanned.
55. A method of claim 54, wherein the method comprises capturing a plurality of images of the object being scanned simultaneously.
56. A method of claim 54 or claim 55, wherein the method includes connecting the master module and the or each slave module to the control arrangement and a storage device via continuous wiring.
57. A method of any one of claims 45 to 56, wherein the method comprises providing the master module and/or the or each slave module with at least one light source for illuminating the object to be scanned.
58. A method of claim 57, wherein the method comprises mounting the light source on or adjacent to the or each camera of the respective master module and/or the or each slave module.
59. A method of claim 58 and any one of claims 47 to 53, wherein the method includes mounting the light source so as to move together with the respective camera.
60. A method of any one of claims 57 to 59, wherein the method comprises mounting the light source on the respective master module and/or the or each slave module so as to shine light in the direction away from the object to be scanned and providing the respective master module and/or the or each slave module with a reflective panel configured to diffuse the light from the respective light source and to direct the diffused light towards the object to be scanned.
61. A method of claim 60, wherein the method comprises mounting the light source on a rear side of respective master module and/or the or each slave module and mounting the reflective panel at the rear side of the respective master module and/or the or each slave module.
62. A method of claim 61, wherein the method comprises providing one or more of the master module and the or each slave module with a light diffusing panel at a front side of the respective master module and/or the or each slave module.
63. A method of any one of claims 35 to 62, wherein the method comprises forming a photo booth having walls defined by the master module and the or each slave module.
64. An apparatus substantially as herein described with reference to and as shown in the accompanying drawings.
65. A method substantially as herein described with reference to the accompanying drawings.