FR2963836A1 - Light box i.e. parallelepiped light caisson, for image processing and capturing device to e.g. capture animated photo of object, has lighting and backlighting units whose light intensities are mutually adapted with respect to one another - Google Patents

Abstract

The box has a lighting system comprising a backlighting unit (8), and a direct lighting unit (7) producing direct lighting inside the box. The lighting and backlighting units possess respective light intensities that are mutually adapted with respect to one another. The backlighting unit is formed of an illuminating and diffusing substrate that is associated with a lighting source e.g. fluorescent tube and/or LED and/or flash lamp and/or organic LED device. A support on which a real object (4) to be treated is arranged, forms a floor plate (10) of the box. An independent claim is also included for a method for capturing an image of an object to be visualized in a fixed or animated manner.

Description

LIGHT BOX FOR IMAGE CAPTURE OF AN OBJECT AND ANIMATED VISUALIZATION

The invention relates to a light box assisting in the shooting of an object or even an individual, intended in particular to be reproduced in two dimensions on a display screen and possibly to be displayed animated by relative displacement. from the point of vision.

The invention will be more particularly described in the use of a box Io light for the photographic representation on a display screen, but applies to any image capture, including for the representation of these images on a support for 'impression.

In recent years, devices have appeared on the market to quickly and simply perform visualizations or animations of objects on a computer screen. Such devices make it possible to capture images of an object and, by processing them by a suitable software, to visualize said object on a screen and preferably in an animated manner.

These devices are designed for easy and quick use by any audience. The photographed object is thus reproduced almost instantaneously on the computer screen, the representation being usable immediately to be for example put online on the Internet, especially on remote commerce sites. Such devices use in a known manner a light box (or light box) in which is placed the object to be reproduced on screen, the box being connected to the computer equipped with the appropriate software.

The light box in the form of a closed enclosure has lighting and optionally a turntable on which is arranged the object to be photographed under 360 °. Means of shooting, such as a camera, are associated with the box, either inside it or outside, then being implemented through a door or hatch left behind. open on one side of the box.

The illumination of the object is provided by one or more light sources placed inside the box and manually controlled Io by switches or dimmers, or electronically controlled from the computer.

The lighting and the background on which the object is photographed are decisive for obtaining an image with a white background and without shadows. However, the current lighting systems do not make it possible to obtain images with a perfectly white background. The user is then required to perform, with the aid of the computer, additional operations of clipping and retouching the images, which ultimately adds to the process and time.

Thus, although some lighting systems are nevertheless specifically chosen and positioned to provide the most homogeneous lighting possible accompanied by a relative whiteness of the background, disadvantages are still present such as: - A background that is not entirely uniform. Indeed, while the edges are white, the central area is more or less grayish. - The side parts of the object which are too bright with consequent overexposure sometimes very important of these 5 areas, especially for products with a glossy surface. The white support on which rests the object which appears very often of grayish color on the final image obtained. The invention therefore aims to provide a light box that does not have the disadvantages of the prior art and facilitates the process of computerized processing of the captured images, providing a rendering of the object on a perfectly white background. According to the invention, the light box comprises a lighting system comprising first lighting means producing a direct illumination inside the box, and a support on which is intended to be arranged the object to be treated. and characterized in that the illumination system further comprises second illumination means constituting backlighting means, the respective light intensities of the first illumination means and backlight means being mutually adapted. one with respect to the other.

The variation of light intensity which is jointly adapted between the first and second illumination means makes it possible to simplify the image processing method while avoiding any retouching of the background, since it provides a visual of the object on a background which is directly perfectly white. .

According to one characteristic, the first lighting means are extinguished while the backlight means are turned on.

This implementation makes it possible, according to a preferred variant of the image capture and processing method, to simplify the computerized processing step.

The first illuminated means of illumination make it possible to correctly illuminate the object for a faithful photographic reproduction, whereas when extinguished and associated with a lighting and an adapted intensity of the backlighting means, the object is visualized in against the light on a perfectly white background. The fusion of the images obtained allows an optimal rendering of the object on a perfectly white background. The process is extremely fast and requires no editing or redrawing of the image. Io Advantageously, the backlight means are arranged on at least one of the inner faces of the box, the one intended to be parallel to the plane containing the objective of the shooting means, the object to be treated being placed between this face of the box and the means of taking is view. Preferably, the backlight means are also arranged at the support of the object.

The support may constitute the floor of the box or a support attached to the floor, the support (the floor or the one attached) being preferably rotatable.

When the backlighting means are integrated in the support of the object, the rotary support or the floor are thus backlit.

Advantageously, the backlighting means are formed of at least one illuminating and diffusing substrate, the substrate being transparent with diffusing function, or being translucent, and associated with one or more light sources. The substrate is for example glass, or plastic material of the polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polycarbonate, polyethylene type.

The first and second illumination means comprise fluorescent tubes and / or light-emitting diodes and / or flash lamps also referred to as "Intense Pulsed Light" devices, and / or organic light-emitting diode (OLED) devices.

Io The first illumination means providing direct illumination are positioned at least at a face of the box opposite to a face provided with the backlighting means.

Preferably, the inside of the box (its inner faces) contains reflective panels for reflecting the direct illumination.

Advantageously, the box further comprises additional lighting means constituting a system for locating and centering the support of the object inside the box and the object itself on its support.

In a variant, the box comprises a plurality of shooting means which are preferably arranged in a quarter circle centered towards the object and inscribed in a plane perpendicular to the support of the object. The invention also relates to a capture and image processing device comprising a light box as described above.

Finally, the invention relates to a method of capturing images of an object 3o to visualize in the form of a still or animated photo, using the light box of the invention. The method operates for a given position of the object: - either in a simple shooting by adjusting the intensity of the first lighting means on the one hand and backlighting means on the other hand, or in one double shooting, the first shooting being carried out with the first lighting means turned on, and the second shooting being triggered after having switched off the first lighting means and switched on and / or intensified the backlighting means . The present invention is now described by way of purely illustrative and non-limiting examples of the scope of the invention, and from the accompanying drawings, in which: FIG. 1 schematically shows a device for generating a d still images, or animated by moving the point of vision around the object, the device incorporating a light box according to the invention; Figure 2 schematically illustrates a light box of the invention, the interior of which is represented by transparency for ease of understanding; FIG. 3 illustrates an exemplary embodiment of the direct lighting means of the light box; Figure 4 illustrates a partial sectional and schematic view of the backlighting means of the light box; Figures 5A and 5B schematically illustrate the images of the object being processed; Figure 5C schematically illustrates the final 2-D visualization image in a 3-D space obtained after processing; Figures 6 and 7 are two alternative embodiments of the light box, respectively without and with a backlit rotatable support attached to the floor, and showing a system for locating and positioning the object in the center of the box .

The light box of the invention is intended to be an example of a device for generating still or moving images in order to display on a computer screen a representation of an object or even of an individual, fixed or animated by moving the point of vision around the object.

1o is schematically illustrated such a device 2 comprising the light box 1 inside which is placed the real object 4 to be reproduced in photography or in photographic animation, shooting means 3 for photographing the object (capturing images), a module 5 for processing shots taken, such as software is integrated with a computer, and a viewing screen 6 such as a computer screen.

The light box 1 makes it possible to capture images of the real object in optimal lighting conditions in order to simplify the operations performed by the processing module, and to display on the screen quickly and without retouching the object.

The shooting means 3 are arranged inside or outside the box. They are connected to the processing module 5, itself connected to the screen 6.

With reference to FIG. 2, the box 1 is preferably in the form of a parallelepipedic box, of dimensions adapted to the type of object 4 to be treated. Also, all kinds of dimensions are conceivable, including dimensions appropriate to the reception of the whole of an individual inside the box.

The box 1 comprises a floor 10 intended to rest horizontally in the sitting position of the box for its operation, a ceiling 11, a bottom wall or bottom 12, a front wall or facade 13 opposite the bottom 12, and opposite side walls 14 and 15 transverse to the bottom and to the facade.

Io The floor 12 serves directly to support the object 4. However, a support 9 separate from the floor and attached to the latter can be envisaged (Figure 5).

In the remainder of the description, all the features referring to the support of the object will be understood as relating to a support attached to the floor or the floor directly.

The box has on one of its faces an opening 16 allowing access to its interior in order to deposit the object to be treated. The opening is intended to remain open or to be partially or fully closed. In addition, the arrangement of the shooting means may be outside or inside the box.

The image-capturing objective of the shooting means 3 is arranged in a plane parallel, inclined or perpendicular to the aperture 16. The imaging means are thus arranged with respect to the object to be photographed. front view, and / or diving and / or underwater. It essentially matters according to the invention that the viewing angle of the lens intersects a plane or a set of backlit planes. The support of the object can be rotated 360 ° in order to capture images of the entire periphery of the object in order to realize an animated representation of the object by apparent displacement of the vision point around said object.

Moreover, it is conceivable to use several means of shooting that would be housed at different locations. In particular, they would be positioned along a quarter-circle inscribed in a plane perpendicular to the rotary support in order to easily generate all the necessary shots for viewing the object in the space along a half-sphere.

The box 1 comprises a lighting system illuminating its interior and breaking down according to the invention into: first lighting means 7 providing direct illumination on the object 4, second lighting means 8 providing a diffusing light on the one hand, on the inner face of the box (here bottom 12) opposite to the positioning plane of the objective of the shooting means 3, and on the other hand, the support on which rests the object (here floor 10).

The first and second illumination means 7 and 8 are operated (on or off) according to the image capture method employed which is described below.

The first lighting means 7 are light sources such as light emitting diodes ("LED" or "LED" in English), or flash lamps or fluorescent tubes. A combination of 30 different types of light sources is conceivable. These lighting means are preferably arranged on the height of the box, along the angles 17 and 18 connecting the front wall 13 to the respective side walls 14 and 15. Combined with interior panels of reflective material preferably side walls, the ceiling and the facade, the lighting means provide illumination of the entire box, and more particularly, of the portion of the object located in front of the objective of the means of shooting 3.

The light sources 7 positioned in the two facing angles 17 and 18 may advantageously be supplemented by light sources placed on the ceiling or at selected locations inside the box.

By way of example, the direct illumination means 7 in the corners consist, as illustrated in FIG. 3, of two bars 70 and 71 carrying LEDs 72. The bars are associated with one another according to their larger size. extension and form an obtuse angle, of the order of 100 to 140 °. Assembled at one corner of the box, the two bars are arranged so that the generated concavity is turned facing the angle of the box.

This reverse V-shaped lighting configuration homogenizes the light emission in the different directions of the space inside the box. Indeed, the disadvantage of an LED is to present variations of the light spectrum between the periphery of its emitted beam and the central zone thereof, the emitted beam having a diffusion angle between 120 and 180 °. Arranging different LEDs at different emission angles makes it possible to correct spectrum variations by mixing the emitted beams, generating a homogenization of the emitted light spectrum and illuminating the object.

The second illumination means 8 constitute, according to the invention, zones of backlighting.

The backlighting zones are formed from diffusing substrates with associated light sources.

FIG. 4 illustrates an exemplary embodiment of the backlighting means comprising a diffusing substrate 80 and light sources 81.

The substrate 80 consists of a transparent or translucent plate, for example based on glass, or plastics material such as polymethyl methacrylate (PMMA), polycarbonate, polyvinyl chloride (PVC), polyethylene. The diffusing function is carried out in a known manner in the mass of the substrate (surface roughness of the substrate or integration of a diffusing organic layer in the substrate), or by being attached to one of the faces of the substrate by a diffusing film. plastic for example.

The light sources 81 are of the LED type, or flash lamps, or still fluorescent tube. The light sources 81 are distributed on the side of one of the faces 82 of the substrate. In the mounted position of the lighting means 8 in the box, the substrate 80, which can in particular constitute the floor 10 of the box and the support of the object, has its face 82 (that associated with the light sources) arranged in a manner opposite to the inside of the box. The light sources 81 are thus arranged under the support of the object 4.

Alternatively, the light sources could be arranged at the edge of the substrate 80.

It is also conceivable to use in another variant of diffusing lighting means, an organic light-emitting diode device, called "OLED" for "Organic Light Emitting Diodes" in Io English, the device being designed specifically to illuminate only on one side and diffusively.

The lighting of the first and second lighting means is preferably controlled in a dissociated manner in order to independently control the variation of light intensity (of a maximum of intensity until extinction) of each of the means. The ignition and dimming are performed using a set of potentiometers placed on the box, or using an electronic card controlled via the computer.

In particular, fluorescent tube illumination is preferably controlled by a dimmable electronic ballast from a digital or analog signal sent by the electronic card.

LED lighting is controlled by PWM modulated power supply (Pulse Width Modulation).

The first and second lighting means are therefore controlled according to the image capture method used. According to the invention, two variants of the image capture method are envisaged. The first variant consists in taking a single shot for each of the positions imposed on the object, by ideally adjusting the intensity of the first and second lighting means 7 and 8.

This first variant is particularly suitable for shooting objects having a matte, non-reflective texture. Such objects accept an intense backlight by the second lighting means 8 and without risk of reflection of this backlight by the surface of the object to be photographed. It is then possible to implement a sufficient intensity of backlight to obtain a perfectly white background without significantly disturbing the direct illumination of the object by the first lighting means 7.

The second variant of the method consists in taking two successive shots of the object in each of the positions imposed vis-à-vis the objective. This second variant is more particularly suitable for objects with large reflective surfaces and whose direct lighting can be disturbed by the reflection of the backlight if it is intense.

The first shot is made under direct illumination of the object via the first lighting means 7, ensuring an enhancement of the object. The intensity of the lighting means, the nature of these means and their number will be chosen according to subjective criteria defined by the operator related to the manner of highlighting the whole of the object or even a part only of the object.

When the first shot is taken, the second lighting means can be turned off or on. The second shot is triggered after having switched off the first lighting means 7 and switched on or intensified the second lighting means 8 providing diffusing light. This light produces a backlight on the background of the shooting means and at the s of the seat of the object, so that a backlit shot is made, the captured object being cut out perfectly on the bottom of the image.

FIGS. 5A and 5B respectively illustrate the two shots thus obtained: Io The image of the object by the first shot (FIG. 5A) exposes the correctly illuminated object without overexposed edge, without milky reflection, with however a background more or less grayish; The image of the object by the second shot (FIG. 5B) makes it possible to obtain a dark object standing out against a perfectly white background.

By a computer processing of fusion of these two images via the module 5, the final image obtained, illustrated in FIG. 5C, provides the object correctly visualized on a perfectly white background. Computer processing is within the reach of the person skilled in the art. Two distinct treatments are proposed here as examples.

The first processing is to extract the background of the second shot to incorporate it at the first shot, or to add an alpha channel to the computer file of the first shot. Such a treatment also makes it easy to create a selection of the background or the outline of the photographed object to modify the background or incorporate the object into another background. The other processing consists of combining the RGB values of each pixel of the first shot with the RGB values of the same pixel of the second shot, while assigning a weighting coefficient which is a function of the value of the RGB components. from the second shot.

It is also important that the object is properly positioned inside the box with respect to the objective of the shooting means capturing the images of the object. With reference to FIGS. 6 and 7, the centering of the object on the floor 10 or the centering of the rotary support 9 to receive the object on the floor 10 is facilitated by a marking system 90 obtained in particular by laser beams. Preferably, the laser beams provide a locating system 90 forming a cross pattern whose intersection constitutes the center of the target area of the objective of the imaging means. The beams are produced by a source 92 arranged at the ceiling 11 and facing the floor. The ignition of the source is preferably electronically controlled.

Claims (11)

REVENDICATIONS1. A light box (1) for capturing images having a lighting system comprising first lighting means (7) providing direct illumination inside the box, and a support (10, 9) on which is intended to be arranged the object to be treated, characterized in that the lighting system further comprises second lighting means (8) constituting backlighting means, the respective light intensities of the first lighting means (7) and backlighting means (8) being mutually adapted to each other. 2. Light box according to claim 1, characterized in that the first lighting means (7) are extinguished while the backlighting means (8) are on. 3. Light box according to claim 1 or 2, characterized in that the backlighting means (8) are arranged on at least one of the inner faces of the box, and preferably at the level of the support (12). , 9). 4. Light box according to any one of the preceding claims, characterized in that the support is the floor (10) of the box or a support (9) attached to the floor, the support being preferably rotatable. 5. Light box according to any one of the preceding claims, characterized in that the backlighting means (8) are formed of at least one illuminating and diffusing substrate, the substrate being transparent diffusing function, or being translucent , and associated with one or more light sources. Light box according to one of the preceding claims, characterized in that the first lighting means (7) and the second lighting means (8) comprise fluorescent tubes and / or light-emitting diodes and / or flash lamps and / or organic light-emitting diode devices, said first lighting means (7) and the second lighting means (8) preferably being of variable intensity. s 7. Light box according to any one of the preceding claims, characterized in that the first illumination means (7) are positioned at least at a face of the box opposite to a face provided with the means of retro- lighting (8). 8. A light box according to any preceding claim Io, characterized in that it comprises additional lighting means (91) constituting a tracking and centering system (9). 9. A light box according to any one of the preceding claims, characterized in that it comprises a plurality of means is shooting (3) arranged in a quarter circle in a plane which is perpendicular to the support of the 'object. An image capture and processing apparatus comprising a light box according to any one of the preceding claims. 11. A method of capturing images of an object to be viewed in a fixed or animated manner, using a light box according to any one of the preceding claims, characterized in that it operates for a given position of the object : - either in a simple shooting by adjusting the intensity of the first lighting means (7) on the one hand and the backlighting means (8) 25 on the other hand, - or in a double setting of view, the first shooting being performed with the first lighting means (7) turned on, and the second shooting being triggered after switching off the first lighting means (7) and switched on and / or intensified the means of backlight (8).