GB2464742A

GB2464742A - Method and Apparatus for 3-D Photography

Info

Publication number: GB2464742A
Application number: GB0819689A
Authority: GB
Inventors: James Perowne
Original assignee: LOBSTER POT PHOTOGRAPHY Ltd
Current assignee: LOBSTER POT PHOTOGRAPHY Ltd
Priority date: 2008-10-27
Filing date: 2008-10-27
Publication date: 2010-04-28
Anticipated expiration: 2028-10-27
Also published as: WO2010049680A2; GB2464742B; GB0819689D0; WO2010049680A3

Abstract

The present invention concerns the preparation of photographs of a subject for display against a so called true white background, especially the preparation of 3-D or 360 degree photographs used to display a subject in a website. The apparatus for the preparation of the photographs is a transparent circular table (fig 1, 1) with a support structure arranged to rotate the table (1) before a true white background formed by a light box 2. A guide 9 is provided to direct light into the foreground side edge 1a of the table so that during photography of a subject disposed in a field of view region 8, light from the guide 9 is discharged from the edge 1b of the table between the subject and the background towards the camera 3. The light discharged at edge 1b is adjusted to an intensity sufficient to eliminate a dark line which would otherwise be formed and require editing out of the photograph before it was useful. The light guide 9 may be a snoot.

Description

INTELLECTUAL

. .... PROPERTY OFFICE Application No. GBO8 19689.1 RTM Date:27 January 2009 The following terms are registered trademarks and should be read as such wherever they occur in this document: Adobe Photoshop Lastolite Elinchrom Intellectual Property Office is an operating name of the Patent Office www.ipo.gov.uk Method And Apparatus For 3-D Photography.

Technical Field

The present invention provides a method and apparatus for the preparation of so-called 3_D photographs sometimes known as 360 degree photography.

A 3-D photograph is a term in the art used to describe a compilation of a number of photographs of a subject each taken from a different point of view moving progressively around an axis of the subject so that, when viewed on a monitor, what appears to be a single image of the subject can be rotated before the viewer.

Such photographs are widely used in commerce to display images of products for sale in online catalogues or websites. The method and apparatus is not intended to produce images with the illusion of depth, as is the conventional meaning of the term 3-D photograph.

It is highly desirable that 3-D photographs of a subject prepared by a studio are supplied to a customer with an appearance as if they are floating in space against a true white background identified in the Adobe Photoshop RGB colour chart as 255.255.255 free of shadows, highlights and glare. The true white background is required, because without it the colours of the subject will be falsely presented. For this reason the websites of end users use it for the

background of their displayed products.

The standard for 3-D, commercial photography requires a photograph to be taken one at each 15° interval around the axis of the subject. Consequently for one full rotation of the subject on one axis, 24 photographs are acquired. If it is desired to produce a 3-D photograph capable of generating the illusion of rotation about more than one axis the number of photographs required increases very significantly.

Prior Art.

A conventional process for preparing 3-D photographs requires that the subject is deployed onto

a white table against a white background. A

photograph is taken and the subject is rotated by 15°, a further photograph is taken and the process repeated until the required sets of photographs has been taken.

These set of photographs is then uploaded in order into a computer for processing into a 3-D photograph.

The illumination of the subject invariably results in the formation of a shadow which appears in the photographs. Other images and reflections also commonly appear in the photograph and these must be eliminated in a photo editor after uploading. This process of editing is laborious, time-consuming and requires a certain level of skill.

In an effort to eliminate shadows from the photographs the inventors in GB 2405282 A have proposed presenting the subject to the camera on a transparent table so that shadows do not form on the surface supporting the subject. The white background is provided by a light box deployed vertically behind

the table. A camera is deployed to have a field of

view across the diameter of the table towards the light box. The transparent table is mounted for rotation, so that a subject placed axially on the table can be rotated before the camera with photographs being taken at the desired angular intervals. A purpose of the transparent table is to enable photographs to be taken of the underside of the subject by adjusting the camera field of view to look up through the underside of the table.

Figures 1A to 2A are diagrams to illustrate a prior art apparatus and method used in the preparation of 3-D photographs. Figures lB and 2B illustrate examples of a single photograph produced by means of the apparatus of figures 1A and 2A.

Referring to figures 1A and 2A the apparatus comprises a table 1 mounted for rotation on a support structure which were the sake of this explanation and simplicity is omitted from the drawing. The table is made from a transparent clear material and is mounted horizontally in front of a light box 2. The light boxes are proprietary apparatus, such as that made by Lastolite. The light box comprises a white fabric stretched across a supporting frame into which are directed conventional studio flashlights so producing a brightly illuminated true white background to the subject. The subject in this instance is a sandle "S" disposed centrally on the table. A camera 3 is

disposed facing the background and the subject and

supported by conventional studio apparatus such as a tripod so that the subject and background falls within the camera field of view 6. Figure lB illustrates the camera field of view. The light source 4 illuminates the front of the subject. With commercial 3-D photography it is commonly required to photograph the subject with the camera looking down as illustrated at an angle of about 25 to 30°. In this case it can be seen that the camera looks through the transparent table to the true white background 2 behind the table 1. The edge of the table appears as a dark line 5 in the field of view above the image of the subject "S" The image is photographed, usually digitally, and after digitising is uploaded into a computer for image processing. In order to eliminate any unwanted

peripheral background, particularly the dark line

produced by the edge of the table, the image is cropped at the crop mask indicated by dotted line 7.

So long as the subject "5" is accurately centred on the table the crop mask will be identical for each of the 24 images to be generated in a set for a 3-D image and the process of cropping the subsequent images can be automated.

Figure 2A illustrates the same apparatus in use to photograph a subject "S" taller than that illustrated in figure IA. Here it can be seen that the subject occludes the black line 5 caused by the edge of the transparent table. When uploaded into the computer four segments of the black line must be carefully and laboriously edited out of the image by a studio operator and at present there is no way of reliably automating this process. Bearing in mind there will be 24 images for the 360° set, and in each case the black line will be different, this makes the preparation of a 3-D image for a subject of this sort very labour intensive and time-consuming.

S

The obvious answer to this problem is to enlarge the table, however, this presents practical difficulties in that the table rapidly becomes extremely large, even for subjects of modest size such as a desk chair. If the table becomes large the supporting structure has to become correspondingly large. It quickly becomes impossible to produce the table from a single sheet of transparent clear material, and even sooner than this the transparent clear material of the table will begin to sag from mechanical stress which tends to produce unwanted reflections, which appear in the photograph.

Statement of Invention.

According to a first aspect of the present invention there is provided an apparatus for use in preparing photographs of a subject comprising: a transparent table supported above the ground to

present a field of view region before a white

background whereby, by illuminating a front view of a subject to a level less than the background luminance the background appears as a true white background in a photograph of the subject.

According to a second aspect of the present invention there is provided an apparatus for use in preparing photographs of a subject comprising: a table transparent to visible white light, supported above the ground to present a field of view region before a

background whereby, to present a subject for

photographing in the field of view region, and

means disposed outside the field of view region

is provided to direct light to radiate from an edge of the table lying in the field of view region towards a viewer.

According to a third aspect of the present invention there is provided an apparatus for use in preparing photographs of a subject comprising: a table transparent to visible white light, supported above the ground to present a field of view region before a background to support a subject for photographing in

the field of view region, and

a light guide to direct light from a source into a light receiving edge of the table so that the light is radiated from a region of the table adjacent an edge of the table lying in the field of view region towards a viewer.

According to a fourth aspect of the present invention there is provided a transparent table supported to present a subject for photography, and a centring camera disposed to simultaneously present an image of a subject on the table and a centring target or graticule, in a monitor, whereby the subject can be accurately positioned at a photographic axis represented by the target or graticule.

In the previous aspects, the table may be mounted for rotation about a vertical axis to facilitate photographing the subject at several angularly spaced intervals.

According to a fifth aspect of the present invention there is provided a transparent table supported for rotation and to present a subject for photography, in a field of view region, said apparatus providing a rotor disposed above the table and coupled thereto for synchronous rotation, whereby a floppy subject may be suspended in the field of view region.

According to a sixth aspect of the present invention there is provided a method of preparing a photograph comprising deploying a subject on a transparent table in a field of view region, arranging the illumination of a true white background and a face of the subject facing a camera and while photographing the subject, introducing light to a light receiving edge of the table so that the light is guided through the table to radiate towards the camera from a region adjacent the edge of the table at an intensity sufficient to render the edge invisible.

Brief Description Of The Drawings.

An apparatus and method embodying the present invention, will now be described, by way of example only, with reference to the accompanying illustrative figures, in which: figure 3A is a perspective view of a first embodiment of the present invention, figure 3B is an enlarged detail of part of the apparatus shown in figure 3A figure 3C is a diagrammatic elevation illustrating certain features of the apparatus shown in figure 3A in operation, figure of 3D is a single cell of a set of 3-D images produced using the apparatus of figures 3, figure 4A is a diagram illustrating a problem experienced with axially centring a subject on the table, and figure 4B shows four cells from a 3-D set illustrating the consequences of off centring the subject, figure 4C is a diagram of the apparatus of figure 3A used to alleviate off-centring, figure 4D is a diagram of a variant of the embodiment of figure 4C, figure 5A is a side elevation diagram of the apparatus of figure 3A illustrating the use of an overlying supporting rotor, and figure 5B is a plan view diagram of the apparatus of figure 3A illustrating a support rotor.

Detailed Description of Drawings.

Figure 3A is a perspective illustration on embodiment of an apparatus suitable for use in taking photographs which appear against a true white background. A true white background is believed to be desirable in order that the colours of the subjects photographed are uniformly influenced by the background. The end users

may also find a true white background more apt to

manipulation for their own purposes. The apparatus is especially adapted to prepare 3-D photographs.

The apparatus comprises a clear transparent support table 1 to support the subject "S" in a field of view region generally indicated by the phantom outline 8, which it is intended will be the region at 9 E

which the field of view of the camera 3 will be

directed. The apparatus is constructed, as is explained in more detail below, so that, apart from the table 1, the components of the apparatus do not

intrude into the field of view.

A light guide is provided by a snoot 9 shown attached to a conventional studio light 10 arranged to project light into a light receiving portion la of an edge of the table 1 so that light L is guided through the table towards a portion lb of the edge of the table lying in the field of view region where it is emitted at Le back towards the camera 3. As may be understood from figure 3A the portion of the edge

lying in the field of view region is substantially

opposite the light receiving portion of the table edge.

The snoot 9 has a receiving collar 11 adapted to couple with and receive light from the studio light 10. The snoot 9 has opposing side walls and upper and lower panels of an opaque material which extend from the collar 11 to an emitting port 12. The prototype snoot 9 was constructed from a card like material.

The emitting port 12 is an elongate rectangular slot adapted to accommodate the light receiving portion la of the table edge so that substantially all the light from the source is directed into the edge. The edge of the table is cut substantially square to the upper and lower major surfaces so that the table edge remains strong. The snoot 9 will preferably be lined with a reflective material to improve the efficiency of the snoot.

In the figures the components of the camera 3, light source 4, snoot 9 and light 10 are shown without visible support to simplify the drawings. However, in practice these components may be supported on conventional studio light and camera stands, or alternatively supporting brackets intended for the purpose of supporting these components may be integrally formed with the apparatus.

The result of the arrangement of the light guide is that light from the studio light 10 is transmitted into the light receiving portion la of the table edge, and most of the light is than transmitted through the material of the table 1 towards the opposite edge of

the table lb.

As has previously been explained the edge of the table appearing in the field of view region 8 appears

as a dark line against the background. It has been

theorised that this is caused by light from other sources in the apparatus being diverted away from the viewer by the optical effects at the edge lb. The viewer in this case may be regarded as the camera.

The result of deploying the light guide and source as described is believed to be that a significant portion of the light "L" transmitted from the studio light 10 impinges on the edge lb of the table within the field of view region 8 and is reflected or refracted back towards the viewer. The result is that with suitable adjustment of the intensity of the light 10 the dark

line 5 disappears from the field of view and

photographs taken with this arrangement appear as shown on figure 3D. Thus no post photographic editing of the photographs is required in order to remove the four portions of dark line 5 shown in figure 2B.

In practice the light level may depend upon the factors such as the width or diameter of the table 1 the table thickness, the material from which the table is made and the condition of the edge lb, however, in the prototype embodiment of the invention using a table formed for example of poly(methyl methacrylate) (PMMA) approximately l.5m in diameter and 12mm thick a light source of 400w provided by an Elinchrom Style 400BX studio lamp delivered through a snoot with a slot width of approximately 300mm at full power was sufficient to eliminate the dark line at the edge lb. Larger tables and or longer edges lb are likely to require more powerful light sources.

Other means of introducing light to the light receiving edge have been considered including a light source such as shaped LED's adapted to conform to the light receiving portion lb or lenses or mirrors shaped to direct light into the edge. However, the present solution of a snoot provides a simple inexpensive and effective solution to the problem of delivering light to the light receiving edge from a conventional studio light source. The side walls and upper and lower panels of the snoot prevent light scattering away from the studio light 10 which alleviates any disruption of the photographers desired lighting of the subject.

For the purpose of clarification the term "clear transparent" means a table formed so that it transmits visible white light with a near uniform attenuation across the visible spectrum so that a true white light source viewed through the table is not corrupted by filtering.

As can be seen in figure 3A the table 1 is made circular to be convenient to mount for rotation about a vertical axis. Mounting for rotation is achieved by a support structure comprising a ground engageable framework 13 which supports a horizontal "C" shaped support member 14. The "C" shaped support member has a radially inner edge 15 with a smaller diameter than the edge diameter of the table 1. With the table 1 overlying and coaxial with the axis of the "C" shaped support member 14, a bearing surface is formed. It will be noted that the field of view region is formed between the ends of the "C" shaped support member 14 where table 1 is unsupported.

A radially and peripherally extending cut-out 14a of the "C" shaped member 14 is removed adjacent the light receiving portion la and substantially opposite the gap in the ends of the "C" shaped portion. The cut-out 14a enables the snoot to be presented to the light receiving edge la of the table 1 unobstructed by the "C" shaped member 14.

Into the bearing surface are set conventional ball bearings rollers 16 spaced at substantially equal angular intervals around the inner rim of the "C" shaped support member 14. Although the bearing surface in the present embodiment is provided by means of roller bearings 16, any suitable alternative Four rollers 17 are mounted on vertical axes to engage the edge of the table 1 so that the table is constrained to rotate around a defined vertical axis central to the four rollers 17.

One of the four rollers 17' is coupled by a belt drive to a rotary motor 18.

Twenty four notches 19 are formed into the rim edge of the table 1 and a micro-switch 20 is arranged to bear against the rim edge with sufficient force to be actuated when it engages each notch 19. The micro-switch provides a sensor to detect the angular position of the table and generate a signal to actuate the shutter of the camera 3.

Alternative forms of angular sensor are contemplated by the inventor including an optical sensor arranged to be responsive to markings on the edge of the table or a sensor coupled to one of the rollers. Alternative shutter and light synchronising mechanisms may provide for variation in the predetermined angular interval so that photos might be taken at 30 degree intervals or 7.5 degree intervals.

When the motor 18 is operated with a sublect axially located on the table within the field of view region 8, the table will be rotated by the rollers 17' as it couples the table to the drive motor 18. In this example every 15° of rotation the shutter of the camera will be actuated to take a photograph synchronised with the generation of light from the light source 10, thus a sequence of twenty four photographs of the subject will be produced in one 3600 rotation of the table in a highly automated manner.

The diagram of figures 4A and 4B illustrate a further problem with producing a 3-D photograph using apparatus such as that shown. Figure 4A illustrates the subject "S", in this case a wine glass, incorrectly located off of the axis of rotation "C" of the table 1. The resulting eccentric rotation of the subject leads to a sequence of photographs as illustrated in figure 4B. The subject in the resulting compiled 3-D photograph will appear to move from side to side in the viewer's screen and get larger and smaller as it rotates, this is highly undesirable. It is not possible to mark the axis on the table since this mark will show in photographs or at the least be very difficult to view by the photographer.

Accordingly the present invention provides a further centre monitoring camera 21 located with a field of view over the axis, preferably vertically over the axis of rotation of the table 1. The camera is connected by wires or wirelessly to a conventional video display unit 22. A targeting sight can be provided by means of the camera, which identifies the axis of rotation of the table 1 on the monitor. The target sight may be provided either by a graticule, generated digitally within the monitor, or presented

on a transparency within the field of view of the

centring camera 21 between the centring camera lens and the table 1, or as in the present case is a target 23 mounted on a panel beneath the table 21. To further assist the photographer the target may take the form of an outline or silhouette of the plan view of the specific subject. In use a subject "S" is moved toward the axis of rotation of the table and is accurately positioned by reference to the monitor 22.

Figure 4D illustrates a variant of the apparatus of figure 4C in which the centring camera 21' is mounted beneath the table 1 to look up through a transparent target 22' through the table 1. This allows for the subject to be photographed from beneath the table by repositioning the camera 3 without suffering unwanted reflections from an overlying sighting camera.

A further problem frequently encountered with photographing floppy subjects, particularly the preparation of photographs for 3-D images of a subject including at least some floppy portions, such as the ankle straps of the sandal shown as subject "S" in figures 5A and 5B, is the requirement to present the floppy portions as they would appear in use. The floppy portions of the subject therefore require support apart from the table 1. Although in some instances this can be provided by some form of framework, in most cases the framework will appear in the 3-D photographs, which is also undesirable, as it adversely influences the appearance of the subject.

Accordingly as the diagram of figures SA and 5B illustrate, the present invention provides a rotor 24 mounted coaxially above the table 1. The rotor 24 is supported by columns 25 extending one each up from the axis of each roller 17 to a position outside the field of view region 8. The rotor 24 comprises a rim 26 which engages with guides 27 extending from the upper portions of the columns 25. The rotor 24 is coupled to the drive roller 17' by a friction roller 28. The relative sizes of the rotor rim 26 and friction roller 27 are selected so that the rotor will rotate synchronously with the table 1. Spokes 29, of which the example has four but which may be as many as desired, extend from the rim to support a hub 30.

Conveniently the targeting camera 21 may be mounted on the hub 30. Guy lines 31 may depend from the spokes or rim of the rotor as required and attached to support the floppy portions of the subject "S".

A suspension "C" ring 32 is mounted on the columns 25 from which a tent 33 of white photographer's fabric depends to the table 1. This acts to exclude unwanted sources of light from the surroundings. By illuminating the tent 33 from outside, using for example the light source 4, the light falling on the subject is rendered relatively diffuse and uniform. A window 34 is formed into the

fabric of the tent 33 opposite the field of view

region 8. A shroud 35 formed of the same fabric is attached to the edges of the window 34 to extend to and closely engage around the lens of a camera 3 so that reflections of the camera 3 which can otherwise

appear within the table field of view region are

minimised to unobtrusive reflections of the camera lens.

The suspension "C" ring and fabric tent also provide the photographer with means to conveniently deploy light baffles such as black panels, out of the field of view region, for example to the sides of the subject "S". Such light sinks can be useful to reduce glare which can otherwise adversely affect the quality of a photograph.

Claims

Claims 1. An apparatus for use in preparing photographs of a subject comprising: a clear transparent support table to support thesubject in a field of view region, anda light guide arranged to project light into a light receiving portion of an edge of the table so that light is guided through the table towards a portion of the edge of the table lying in the field of view region.
2. An apparatus according to claim 1 wherein the light receiving portion is opposite the portion of theedge lying in the field of view region.
3. An apparatus according to one of claims 1 or 2 wherein the light guide is a snoot with a receiving dock adapted to receive light from a conventional light source and an emitting port adapted to engage closely with the light receiving portion of the table edge so that substantially all the light from the source can be directed into the edge.
4. An apparatus according to claim 3 wherein the emitting port is a slot formed in the body of the snoot which closely engages the surfaces of the table adjacent the light receiving portion.
5. An apparatus according to claim 3 or claim 4 wherein the snoot is lined with a reflective material.
6. An apparatus according to any one of the preceding claims wherein the light guide comprises means to prevent light scattering away from the light receiving edge of the table.
7. An apparatus according to any one of the preceding claims wherein the table is mounted for rotation.
8. An apparatus according to claim 7 wherein the light guide is fixedly mounted with respect to thetable.
9. Apparatus according to one of claims 7 or 8 wherein the table is circular and mounted on a ground engageable support structure having an arrangement of bearings and guides to constrain the table to rotate about a vertical axis.
10. Apparatus according to claim 9 wherein none of the support structure lies within the field of view region.
11. Apparatus according to one of claims 9 or 10 comprising a motor coupled to rotate the table.
12. Apparatus according to one of claims 9 to 11 including a sensor able to detect when the table is rotated a predetermined angular interval and to emit signals to actuate the shutter of a camera.
13. Apparatus according to anyone of claims 7 to 12 wherein a sighting camera is arranged to have a field of view above or below the table to look up or down along the axis of rotation of the table and provided with a sight indicative of the location of the axis of rotation of the table.
14. Apparatus according to anyone of claims 7 to 13 wherein a rotor is mounted to rotate coaxially and synchronously above the table whereby the subject may be further supported by guy lines depending from the rotor.
15. Apparatus according to any one of the preceding claims wherein, a tent depends from an overlying supporting frame to the rim of the table, and includes a window opposing the field of view region to enable a S camera to be directed at the field of view region, and a shroud extending from the window to engage with the lens of a camera.
16. A method of preparing photographs comprising the steps of: disposing a subject on a clear transparentsupport table in a field of view of a camera,projecting light into a light receiving portion of an edge of the table towards a portion of an edge of the table in the field of view, and simultaneouslyphotographing the subject in the field of view.
17. A method according to claim 16 comprising the step of photographing the subject against a true whitebackground.
18. A method according to claim 16 or 17 comprising the step of rotating the table by a predetermined angular increment and repeating the steps of claim 16.
19. A method according to claime 18 comprising repeating the steps of claims 16 to 18 until the table returns to its starting angular position.
20. A method according to any one of claims 16 to 19 comprising uploading all the photographs of the subject to a computer, and compiling the set of photographs into a 3-D image.
21. A method according to claim 16 comprising producing the photographs against a true whitebackground, without any post photography editingrequired other than cropping away unwanted peripheral images.
22. A method according to any one of claims 18 to 21 comprising; simultaneously viewing a target provided to indicate the rotary axis of the table and the position of the subject on the table through a sighting camera arranged with a field of view looking down onto the table or looking up through the table.
23. A method according to any one of claims 18 to 22 comprising suspending floppy portions of a subject by guy lines depending from a rotor deployed co-axially overlying the axis of the table and driven to rotate synchronously with the rotation of the table.
24. A photograph produced by a method according to any one of claims 16 to 23.
25. A3-D photograph produced according to claim 24.
26. An apparatus f or use in preparing photographs of a subject comprising: a clear transparent support table, said table mounted for rotation about an vertical axis and tosupport the subject in a field of view region anda sighting camera arranged to have a field ofview looking down on or up under the table along the axis of rotation of the table in order to simultaneously view the subject and a centring target to indicate the accurate centring of the subject.
27. An apparatus for use in preparing photographs of a subject comprising: a clear transparent support table, said table mounted for rotation about a vertical axis and tosupport the subject in a field of view region anda rotor disposed overlying the table to rotate concentrically and synchronously therewith whereby floppy portions of a subject can be supported above the table by fixing them relative to the rotor.