Interdigital Ce Patent Holdings

Interdigital Vc Holdings, Inc.

Thomson Licensing

Interdigital Ce Patent Holdings, Sas

Mozhdeh Seifi

Valter Drazic

Neus Sabater

Laurent Blonde

Erik Reinhard

Guillaume Boisson

Paul Kerbiriou

Benoit Vandame

Wei Hu

Franck Galpin

Arno Schubert

Olivier Bureller

Guillaume Poirier

Nues Sabater

Laurent BlondÉ

The disclosure concerns a method for manufacturing a device for forming at least one focused beam in a near zone, from an electromagnetic wave incident on said device. The method includes depositing a dielectric material layer with a first refractive index on a substrate layer, creating at least one cavity by a microfabrication technique in the dielectric material layer, the device for forming at least one focused beam in a near zone of the substrate layer () and the dielectric material layer, filling the at least one cavity with a material having a second refractive index lower than the first refractive index, determining a deviation between a measured focused beam radiation angle obtained from the device for forming at least one focused beam in a near zone and an expected focused beam radiation angle and modifying locally at least one of the two refractive indexes according to the deviation.

Method for manufacturing a device for forming at least one focused beam in a near zone

A method for reducing the parameters defining an acquired light field ray which enables only the colour associated with the light field ray to be stored instead of 4 light field co-ordinates (x,y,i,j) and its associated colour.

Light field data representation

In one embodiment, it is proposed a method for encoding a light field content. The method is remarkable in that it comprises: &#x2014;obtaining, for a set of light rays () associated with said light field content, four coordinates per light ray from a two planes parametrization () of said light field content; &#x2014;obtaining (), for each light ray from said set, two coordinates from said four coordinates, corresponding to a projection of said light rays from said set onto a plane (, P) perpendicular to two planes used in said two planes parametrization, defining points in a first 2D ray diagram (&#x3a0;(&#x3c7;, &#x3c7;), &#x3a0;(&#x3c7;, &#x3c7;)); &#x2014;applying () a discrete Radon transform on said first 2D ray diagram (&#x3a0;(&#x3c7;, &#x3c7;), &#x3a0;(&#x3c7;, &#x3c7;)) that delivers lines of interest in said first 2D ray diagram; &#x2014;encoding () said lines of interest into encoded lines of interest; and&#x2014;storing () said encoded lines of interest.

Method for encoding a light field content

There are several types of plenoptic devices and camera arrays available on the market, and all these light field acquisition devices have their proprietary file format. However, there is no standard supporting the acquisition and transmission of multi-dimensional information. It is interesting to obtain information related to a correspondence between pixels of a sensor of said optical acquisition system and an object space of said optical acquisition system. Indeed, knowing which portion of the object space of an optical acquisition system a pixel belonging to the sensor of said optical acquisition system is sensing enables the improvement of signal processing operations. The notion of pixel beam, which represents a volume occupied by a set of rays of light in an object space of an optical system of a camera is thus introduce.

Apparatus and a method for encoding an image captured by an optical acquisition system

There are several types of plenoptic devices and camera arrays available on the market, and all these light field acquisition devices have their proprietary file format. However, there is no standard supporting the acquisition and transmission of multi-dimensional information. It is interesting to obtain information related to a correspondence between pixels of a sensor of said optical acquisition system and an object space of said optical acquisition system. Indeed, knowing which portion of the object space of an optical acquisition system a pixel belonging to the sensor of said optical acquisition system is sensing enables the improvement of signal processing operations. The notion of pixel beam, which represents a volume occupied by a set of rays of light in an object space of an optical system of a camera along with a compact format for storing such information is thus introduce.

Method and an apparatus for generating data representative of a pixel beam

In one embodiment, it is proposed a method for obtaining at least one sub-aperture image being associated with one view, from raw light field data corresponding to recorded data by an array of pixels sensors positioned behind an array of micro-lenses in a light field camera, each of said pixel sensor recording a linear mixing of up to four different views. The method is remarkable in that it comprises applying a signal separation process on said raw data by using an inverse of a mixing matrix A, said mixing matrix comprising coefficients that convey weighting information of said up to four different views recorded by a pixel sensor.

Method for obtaining at least one sub-aperture image being associated with one view

A plenoptic camera having a camera lens, a microlens array and a photosensors array is described. An optical device is arranged before the camera lens according to a light-traveling direction of a light flux entering the plenoptic camera. The optical device includes a first layer that is controllable between a transmissive mode and a scattering mode and at least one light source arranged at a border of the optical device. A method for controlling the plenoptic camera is also described.

Plenoptic camera and method of controlling the same

Apparatus and a method for calibrating an optical aquisition system

Methods and apparatus for estimating a depth of unfocused plenoptic data are suggested. The method includes: determining a level of homogeneity of micro-lens images of unfocused plenoptic data; determining pixels of the micro-lens images of the unfocused plenoptic unfocused plenoptic data which either have disparities equal to zero or belong to homogeneous areas as a function of the calculated level of homogeneity of the micro-lens images of the unfocused plenoptic data; and estimating the depth of the unfocused plenoptic data by a disparity estimation without considering the determined pixels. With the disclosure, by pre-processing the raw data, it can prevent any disparity estimation method to spend time on estimating disparities for: (i) pixels that are in focus, (ii) pixels that belong to homogenous areas of the scene.

Method and apparatus for estimating depth of unfocused plenoptic data

A plenoptic camera has a moveable micro-lens array in optical registration with an image sensor. A first prime mover displaces the micro-lens array synchronized with a frame rate for the camera to obtain multi-resolution of a scene. A second prime mover displaces the image sensor to increase color sampling.

Hybrid plenoptic camera

The disclosure addresses the vignetting effect caused on an image captured by lightfield camera. A method to compensate for the vignetting effect for a lightfield camera comprising an image sensor array including plurality of photosites. The method includes the operations of obtaining luminance values from the each photosite; obtaining a set of weight values for compensating the vignetting effect for the each photosite being associated with a present setting of the lightfield camera; and changing the luminance values of the each photosite based on the obtained a set of the weight values.

Method and apparatus for correcting vignetting effect caused on an image captured by lightfield cameras

A method of obtaining one or more HDR images representative of a scene is described. To reach that aim, the method includes obtaining several LDR images representative of the scene. The method further includes identifying one or more first pixels having a pixel value that is greater than a first determined value (i.e. corresponding to underexposed pixels) or having a pixel value that is less than a second determined value (i.e. corresponding to overexposed pixels). The method further includes determining one second pixel, in one or more other LDR images, that corresponds to the first pixel. In a block of pixels centered on the second pixel, weighting values are determined that are representative of similarity between the second pixel and the other pixels of the block. A HDR image is finally obtained by determining and assigning a new pixel value to the first pixel. The new value is calculated based on weighting values and pixel values associated with pixels of a block of pixels centered on the first pixel.

Method and device for obtaining a HDR image by graph signal processing

A light-field capture device including a photo-sensor, a main lens configured to refract light from a scene towards an image focal field, a micro-lens array positioned in the image focal field between the main lens and the photo-sensor, each micro-lens being configured to project a micro-lens image onto a respective dedicated area of the photo-sensor. The light-field capture device is provided with at least one compressive sensing calculation unit connected to at least one of the dedicated areas and configured to calculate data such as for example standard deviation data representative of the homogeneity of input pixels of said dedicated area, and to provide output data representative of the input pixels of said dedicated area; the output data comprising either a number of output pixels corresponding to the number of input pixels, or a single output pixel, depending on the relative value of the homoegeneity compared with a threshold.

Light field imaging device

A method for obtaining a refocused image from a 4D raw light field data for a given focus (z) is described. The method is remarkable in that it comprises applying a shift correction parameter on shifted and summed images from said 4D raw light field data, the shifted and summed images being defined as a function of the given focus (z), and the shift correction parameter (&#x394;) including, for at least a part of pixels of at least two sub-aperture images derived from at least one 4D light field data of a test-chart image, determined shifts for pixels belonging to the part of pixels between the at least two sub-aperture images, the test-chart image comprising patterns adequate to compute disparities between the sub-apertures images.

Method for obtaining a refocused image from a 4D raw light field data using a shift correction parameter

A method of calibrating an image acquisition device is described. The method includes emitting at least one light source pattern in an object space of the image acquisition device, adjusting one of the source patterns until an image pattern of the source pattern formed on a sensor of the image acquisition device exhibit a shape which centroid corresponds to a centroid of a reference pixel of the sensor, called a target image pattern and analyzing the adjusted source pattern and estimating therefrom at least one characteristic of a pixel beam directed to the reference pixel from the adjusted source pattern.

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Thorigne-Fouillard, France

Mozhdeh Seifi