FR3125939A1 - System for acquiring and processing chroma key type photographic images of a subject to be photographed - Google Patents

Abstract

The invention relates to a system for acquiring and processing chroma key type photographic images of a subject to be photographed comprising:-a green background (7); -a terminal (2) for acquiring and processing chroma key type photographic images comprising: -a camera (21); -a flash device (22); -an image processing unit (3), configured to store and process the photograph obtained with chroma key type processing;-a dispersion reflector (), interposed between the camera (21) and the flash device (22), and oriented facing the flash device (22), configured to reflect the incident light rays coming from the light source towards all directions in space according to a chosen maximum angle of reflection; and -a reflection module (5), incorporating an arrangement of at least two so-called orientation reflectors (51,52), arranged around the flash device (22), and able to redirect all the light rays reflected towards a same direction of space chosen to illuminate the subject (13), thus making it possible to obtain indirect rays parallel to each other, and a light of chosen intensity towards the subject (), the emitted light being configured to minimize shadows cast () of the subject () on said green background () by inducing cast shadows of reduced intensity and arranged behind the subject (13) to be photographed over a defined area (14) outside the field of visibility (α) of the camera (21).

Description

System for acquiring and processing chroma key type photographic images of a subject to be photographed

The present invention relates to a system for acquiring and processing chroma key type photographic images of a subject to be photographed.

Many advances have been made in the field of photographic keying via systems using green backgrounds, in order to digitally key a subject into a chosen background so that said keying appears natural and that the photograph as well obtained seems credible.

However, the main problem encountered by the existing systems is posed by the shadows cast by the subject on the green background creating zones interfering with the clipping, the current automatic clipping systems recognizing the shadows cast as belonging to the subject photographed.

Photo studio type systems are known involvingmany diffused lighting placed at different positions and angles of the subject to eliminate cast shadows.

Such systems have the disadvantage of being very bulky and difficult to set up.

These systems are also systematically chosen by existing systems, unlike front lighting, which gives cast shadows that interfere with any digital clipping.

Such systems also have the disadvantage of not being able to be parameterized correctly without professional knowledge.

There are also known systems for eliminating cast shadows digitally.

Such systems have the disadvantage of being subject to the vagaries of shadow identification errors.

The present invention overcomes these drawbacks.

The invention relates to a system for acquiring and processing chroma key type photographic images of a subject to be photographed, comprising:
A green background, configured to be placed at a chosen distance from the shooting module behind the subject to be photographed, and capable of forming a set of pixels with properties differentiated from the pixels forming the subject to be photographed on the digital rendering of the photograph as well obtained;
- a chroma key type photographic image acquisition and processing terminal comprising:
- A camera capable of photographing the subject inserted between the green background and the camera, configured to allow the acquisition and storage of a digital photograph of a subject located in front of the green background;
- A flash device, forming a light source, and placed at a chosen distance at the rear of the camera; And
- an image processing unit, configured to store and process the photograph obtained with a chroma key type processing.

• un réflecteur de dispersion intercalé entre l’appareil photographique et le dispositif de flash, et orienté face au dispositif de flash, configuré pour réfléchir les rayons lumineux incidents en provenance de la source lumineuse vers toutes les directions de l’espace selon un angle maximal de réflexion choisi,
• un module de réflexion, intégrant un agencement d’au moins deux réflecteurs dits d’orientation, disposé autour du dispositif de flash, et apte à réorienter parallèlement tous les rayons lumineux reflétés vers une même direction de l’espace choisie pour éclairer le sujet, permettant ainsi d’obtenir des rayons indirects parallèles entre eux, et une lumière d’intensité choisie vers le sujet, la lumière émise étant configurée pour minimiser les ombres portées du sujet sur ledit fond vert en induisant des ombres portées d’intensité réduite et disposées derrière le sujet à photographier sur une zone définie hors du champs de visibilité de l’appareil photographique.

According to a general definition of the invention, the acquisition and processing terminal of the system for acquiring and processing chroma key type photographic images of a subject to be photographed comprises:

• a dispersion reflector interposed between the camera and the flash device, and oriented facing the flash device, configured to reflect the incident light rays coming from the light source towards all directions in space according to a maximum angle of chosen reflection,
• a reflection module, integrating an arrangement of at least two so-called orientation reflectors, arranged around the flash device, and capable of redirecting all the reflected light rays in parallel towards the same direction in space chosen to illuminate the subject, thus making it possible to obtain indirect rays parallel to each other, and a light of chosen intensity towards the subject, the emitted light being configured to minimize the shadows cast by the subject on said green background by inducing cast shadows of reduced intensity and arranged behind the subject to be photographed on a defined area outside the field of vision of the camera.

In practice, the reflection module comprises at least four orientation reflectors arranged below, above, to the right and to the left of the dispersion reflector, each reflector of the reflection module comprising a specific chosen orientation, configured to reflect the incident rays from the scatter reflector to the subject, and configured to allow the emission of indirect rays parallel to each other, and a light of chosen intensity towards the subject.

In addition, the processing unit is capable of digitally processing the photograph thus stored by identifying the pixels of said digital photograph defining the subject and the green background, the visible cast shadows being suppressed by the parallel incident light rays, and configured to perform automatic clipping of said subject by applying transparency properties to the pixels identified as belonging to the green background.

According to an embodiment in accordance with the invention, the orientation reflectors have a reflection surface incorporating a matt white reflective material capable of limiting the intensity of the light rays emitted towards the subject.

For example, the arrangement of so-called orientation reflectors belongs to the group formed by prisms with a trapezoidal base.

In practice, the system comprises printing means, capable of printing the photograph thus processed.

In practice, the acquisition and processing terminal includes a preview screen, configured to display the result after each shot for the user.

According to an embodiment in accordance with the invention, all the components of the system are integrated into a single box of chosen size.

For example, the camera is of the canon® type.

In practice, the system further includes means of photographic activation belonging to the group formed by manual using a wireless remote control, automatic through the application integrated in the computer after a countdown.

Advantageously, the system according to the invention makes it possible to eliminate the cast shadows visible with a particular frontal lighting and thus allow effective lighting of the subject while allowing the chroma key software to obtain an image comprising a precisely outlined subject.

Surprisingly, such lighting also makes it possible to limit the sensitivity of the sensor, thus making it possible to obtain a digital image with an extremely low noise level.

• représente schématiquement la borne du système dans une vue de droite conforme à l’invention ;
• représente schématiquement la borne du système dans une vue explosée de gauche conforme à l’invention ;
• représente schématiquement la borne du système dans une vue de face conforme à l’invention ;
• représente schématiquement la borne du système dans une vue de profil et explosée conforme à l’invention ;
• représente schématiquement une vue explosée des éléments d’éclairage et de prise de vue de la borne conforme à l’invention ;
• représente schématiquement une vue de profil des éléments d’éclairage et de prise de vue de la borne du système en fonctionnement conforme à l’invention ;
• représente schématiquement un second mode de réalisation conforme à l’invention ; et
• représente schématiquement le système selon l’invention en position de prise de vue d’un sujet à photographier.

Other advantages and characteristics of the invention will appear on examination of the description and the drawings in which:

• schematically represents the terminal of the system in a right view in accordance with the invention;
• schematically represents the terminal of the system in an exploded view from the left in accordance with the invention;
• schematically represents the terminal of the system in a front view in accordance with the invention;
• schematically represents the terminal of the system in a profile and exploded view in accordance with the invention;
• schematically represents an exploded view of the lighting and shooting elements of the bollard according to the invention;
• schematically represents a profile view of the lighting and shooting elements of the terminal of the system in operation according to the invention;
• schematically represents a second embodiment in accordance with the invention; And
• schematically represents the system according to the invention in the shooting position of a subject to be photographed.

With reference to FIGS. 1 to 8 , the system for acquiring and processing chroma key type photographic images of a subject to be photographed comprises a terminal 2 as well as a green background 7 placed at a chosen distance from said terminal 2 .

Terminal 2 of the system according to the invention comprises photographic means, lighting means, as well as means for processing the captured photograph.

Terminal 2 includes a camera 21, able to photograph the subject 13 inserted between the green background 7 and the camera 21.

By way of non-limiting example, the camera is of the canon® brand, the only brand to provide the source codes (SDK) allowing its remote control.

Terminal 2 further comprises lighting means arranged in a box 9, and comprising a flash device 22, a dispersion reflector 4, and a reflection module 5.

In practice, the camera 21 is arranged centrally and vertically on the front face of the reflection module 5.

By way of non-limiting example, the flash device 22 has a power of 400 Watts/second adjustable in power if necessary. Its triggering is wired by the camera.

The flash device 22, forming a light source, and disposed at a chosen distance to the rear of the camera 21, and capable of directly illuminating the dispersion reflector 4, said dispersion reflector 4 being positioned directly behind the camera photographic 21.

The dispersion reflector 4, interposed between the camera 21 and the flash device 22, and oriented facing the flash device 22, configured to reflect the incident light rays coming from the light source towards all directions in space according to a chosen maximum angle of reflection.

In practice, the maximum angle chosen is 180°.

According to a particular embodiment of the invention, the dispersion reflector 4 comprises a portion of a sphere 30 centimeters in diameter, covered with a material having neutral reflective properties, and whose flat face is directly in contact with the camera. 21.

Terminal 2 of the system according to the invention further comprises a reflection module 5, integrating an arrangement of at least two so-called orientation reflectors 51, 52, arranged around the flash device 22, and able to redirect all the rays in parallel. light reflected by the dispersion reflector 4 towards the same direction in space, chosen to illuminate the subject 13, and thus making it possible to obtain indirect rays parallel to each other having a single orientation.

In practice, the reflection module comprises at least four orientation reflectors 51, 52, 53, 54 arranged below, above, to the right and to the left of the dispersion reflector 4, each reflector of the reflection module comprising a own orientation chosen, configured to reflect the incident rays coming from the scattering reflector 4 towards the subject 13, and configured to allow the emission of indirect rays parallel to each other.

According to a particular embodiment of the invention, the reflection module 5 comprises a top reflector 51, placed above the flash device 22, and a bottom reflector 52 placed below the flash device 22, the two reflectors forming a chosen angle depending on the photographic area to be covered.

According to a first embodiment of the invention, the reflection module 5 further comprises right 53 and left 54 reflectors, parallel to each other, and fixed integrally to the top 51 and bottom 52 reflectors, making it possible to form said reflection module 5 .

According to a second embodiment of the invention, the right 53 and left 54 reflectors are arranged at an angle identical to the top 51 and bottom 52 reflectors.

By way of example, the assembly forming the reflection module 5 describes a prism with a trapezoidal base, having the flash device 22 on its smallest face, the latter allowing a good distribution of the light around the camera in order to to obtain a uniform green background 7.

By way of non-limiting example, the orientation reflectors 51,52,53,54 have a matte white reflection surface incorporating a reflective material capable of limiting the intensity of the light rays emitted towards the subject belonging to the group formed

In practice, the flash device 22 emits light unidirectionally towards the dispersion reflector 4, the light rays being dispersed at 180° towards the internal faces of the reflection module 5, said light rays being finally reflected by the orientation reflectors 51, 52 unilaterally towards the subject 13 to be photographed and the green background 7, said light rays thus reflected being mutually parallel.

In addition, the reflection module 5 comprises a diffuser 11, configured to be traversed by the light reflected by the orientation reflectors 51,52, said diffuser comprises transparency properties chosen to allow the incident rays to maintain their orientation towards each other. relative to the others, while decreasing the intensity of said light rays.

According to a particular embodiment of the invention, the diffuser 11 comprising a flat surface composed of matt white frosted plexiglass, and having a circular opening of chosen diameter, said diameter being defined as the exact diameter of the objective of the camera 21, and thus allowing the lens to be inserted, thus keeping it in place in the center of the front face of the reflection module 5.

Such an arrangement with diffuser 11 makes it possible to obtain a softer light, forming shadows cast attenuated and less contrasted on the green background 7, while the central position of the camera 21 allows a uniform light on the subject 13 and allows to obtain uniform front lighting over the entire shooting zone defined by the shooting angle α without the subject 13 having to stick to the green background 7 to limit the shadows cast, and makes it possible to avoid using a flash with too much power to obtain satisfactory lighting.

The arrangement also makes it possible to limit the sensitivity of the sensor of the camera 21 to ISOs less than or equal to ISO 200, thus allowing a limitation of the noise on the digital rendering of the photograph thus taken and thus improving the definition of said photograph. .

In practice, the light emitted by the orientation reflectors 51, 52 is configured to minimize the shadows cast by the subject 13 on said green background 7, by inducing cast shadows of reduced intensity and arranged behind the subject 13 to be photographed on a defined zone 14 outside the field of visibility α of the camera 21.

Surprisingly, the reduction in the intensity of the incident rays coupled with their parallel orientation thus obtained, makes it possible to minimize the shadows cast while softening the hardness of said shadows cast on the green background 7, and thus making it possible to identify in a manner much more precisely the pixels belonging to the green background 7, the pixels identified as belonging to the subject 13 for processing.

In practice, all the components of the photographic means, the lighting means and the reflection means are integrated into a single box of chosen size, allowing their implementation according to frontal lighting of the subject 13.

Terminal 2 for acquiring and processing chroma key type photographic images further comprises an image processing unit 3, configured to store and process the photograph obtained with chroma key type processing, and configured to automatically process digitally the photograph thus stored by identifying the pixels of said digital photograph defining the subject 13 and the green background 7, the visible cast shadows being suppressed by the parallel incident light rays.

Once the pixels have been identified and assigned, the processing unit is configured to carry out an automatic clipping of said subject 13 by applying transparency properties to the pixels identified as belonging to the green background 7.

In practice, the processing unit is configured to include the reflection parameters of the reflection module 5, the parameters of the flash device used, of the diffuser and of the properties of the green background 7, of the camera used in the processing carried out .

The parameters belong without limitation to the group formed by the power of the lighting of the flash device 22, the color, orientation, angle, luminous intensity of the lighting obtained, sensitivity of the sensor of the camera 21, aperture and speed of shutter of the camera 21.

According to a particular embodiment of the invention, the processing unit can then receive a command defining the background to be applied by a user once the automatic clipping has been carried out, and thus allow the automatic assembly of the selected background with the subject 13 thus diverted.

According to an alternative embodiment of the invention, the processing unit 3 is configured to allow the recording of the image on a green background 7, the image with assembled background and the image with application of transparency properties to the green background 7.

According to another alternative embodiment of the invention, the processing unit 3 is configured to allow the assembly of at least two different photos of subjects with application of transparency properties to the green background 7, and capable of applying a background selected by the user on two subjects integrated into the image, making it possible to obtain a multiple definition image of the number of stitched images and the basic resolution of each shot, and thus obtain for a large number of assembled images, i.e. at least five images, a resolution superior to the most advanced sensors on the market.

The processing unit 3 is configured to allow the construction of a dynamic image with the possibility of adding the images taken making it possible to obtain an image of added resolution.

By way of example, the processing unit 3 comprises a computer which is responsible for storing and processing the digital photographs of the subject 13.

According to one embodiment of the invention, the terminal 2 of the system according to the invention further comprises printing means, capable of printing the photograph as soon as the processing and the assembly are carried out, said printed images leaving through a print output 81.

The acquisition and processing terminal 2 according to the invention further comprises a preview screen 12, configured to display the assembly and processing result after each shot for the user.

The system according to the invention further comprises a green background 7 is configured to be placed at a chosen distance from the terminal 2 behind the subject 13 to be photographed, and capable of forming a set of pixels of properties differentiated from the pixels forming the subject to be photographed. photograph on the digital rendering of the photograph thus obtained.

By way of non-limiting example, the green background 7 is composed of a matte green colored carpet, said carpet making it possible to avoid a hot spot linked to lighting of the subject 13 from the front.

In practice, the system according to the invention further comprises a means of activating the photographic shooting belonging to the group formed by manual using a wireless remote control, automatically via the application integrated in the unit processing after a countdown.

Advantageously, the arrangement of the terminal 2 and the green background 7 allows shooting, automatic clipping and the production of a clear photographic rendering for the user without the need for particular professional knowledge.

Claims (10)

System for acquiring and processing chroma key type photographic images of a subject to be photographed, comprising:
- a green background (7), configured to be arranged behind the subject (13) to be photographed at a chosen distance from a terminal (2), and capable of forming a set of pixels with properties differentiated from the pixels forming the subject (13 ) to be photographed on the digital rendering of the photograph thus obtained;
-a terminal (2) for acquiring and processing chroma key type photographic images comprising:
-a camera (21) capable of photographing the subject (13) inserted between the green background and the camera, configured to allow the acquisition and storage of a digital photograph of a subject (13) located in front of the green background (7);
-a flash device (22), forming a light source, and disposed at a chosen distance to the rear of the camera (21);
-an image processing unit (3), configured to store and process the photograph obtained with a chroma key type processing;
characterized in that the acquisition and processing terminal (3) comprises:
- a dispersion reflector (4), interposed between the camera (21) and the flash device (22), and oriented facing the flash device (22), configured to reflect the incident light rays coming from the source luminous towards all directions in space according to a chosen maximum angle of reflection; And
- a reflection module (5), integrating an arrangement of at least two so-called orientation reflectors (51,52), arranged around the flash device (22), and able to redirect all the reflected light rays in parallel towards a same direction of space chosen to illuminate the subject (13), thus making it possible to obtain indirect rays parallel to each other, and a light of chosen intensity towards the subject (13), the emitted light being configured to minimize shadows of the subject (13) on said green background (7) by inducing cast shadows of reduced intensity and arranged behind the subject (13) to be photographed over a defined zone (14) outside the field of visibility (α) of the camera (21). System for acquiring and processing photographic images of the chroma key type according to claim 1, characterized in that the reflection module (5) comprises at least four orientation reflectors (51,52,53,54) arranged at the below, above, to the right and to the left of the scattering reflector, each reflector of the reflection module (51,52,53,54) comprising a specific chosen orientation, configured to reflect the incident rays coming from the scattering reflector (4) towards the subject (13), and configured to allow the emission of indirect rays parallel to each other, and a light of chosen intensity towards the subject (13). System for acquiring and processing photographic images of the chroma key type according to claim 1 or 2, characterized in that the processing unit (3) is capable of digitally processing the photograph thus stored by identifying the pixels of the said photograph digital defining the subject (13) and the green background (7), the visible cast shadows being suppressed by the parallel incident light rays, and configured to carry out automatic clipping of said subject (13) by applying transparency properties to the pixels identified as belonging to the green background (7). System for acquiring and processing photographic images of the chroma key type according to one of Claims 1 to 3, characterized in that the orientation reflectors (51,52,53,54) have a reflection surface incorporating a matte white reflective material able to limit the intensity of the light rays emitted towards the subject (13). System for acquiring and processing photographic images of the chroma key type according to one of Claims 1 to 4, characterized in that the arrangement of the so-called orientation reflectors (51,52,53,54) belongs to the group formed by trapezoidal prisms. Photographic acquisition system according to one of Claims 1 to 5, characterized in that the system comprises printing means (8), capable of printing the photograph thus processed. Photographic acquisition system according to one of Claims 1 to 6, characterized in that the acquisition and processing terminal (2) comprises a preview screen (12), configured to display the result after each shot to the user. System for acquiring and processing photographic images of the chroma key type according to Claims 1 to 7, characterized in that all the components of the system are integrated into a single box (9) of chosen size. Chroma key type photographic image acquisition and processing system according to Claims 1 to 8, characterized in that the camera (21) is of the Canon® type. System for acquiring and processing photographic images of the chroma key type according to Claims 1 to 9, characterized in that the system further comprises photographic activation means belonging to the group formed by manual using a wireless remote control, automatic through the built-in application in the computer after a countdown.