Method and apparatus to encode and decode images of points of a sphere
AssigneeInterDigital VC Holdings, Inc.
InventorsJulien Fleureau, Bertrand Chupeau, Renaud Dore
Life of this patent
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Abstract
Methods and devices are provided to encode points of a sphere onto an image by projecting them as a function of an isotropic region guided mapping operator and/or to decode pixels of an image onto a sphere by de-projected them according to the same parametrized mapping operator. A region of interest is determined on the sphere and the angular resolution of pixels of the image is modulated as a function of their distance to the reference pixel corresponding to the center of the region of interest. Chosen angular resolutions and size of the region of interest are associated with the image and encoded in a stream.
Claims16
A method comprising projecting points of an area of a sphere onto a pixel of an image, surface of the area being a function of a distance between the pixel and a reference pixel of the image in both dimensions of an image plane, wherein the reference pixel is a projection of a reference point and wherein the surface varies according to a continuous spherical mapping operator that is a function of:
- coordinates of the reference pixel corresponding to a center of a region of interest defined by the continuous spherical mapping operator,
- an angular window around the reference point,
- an angular resolution at the reference pixel,
- an angular resolution at pixels corresponding to border of the angular window.
A device comprising a processor configured to project points of an area of a sphere onto a pixel of an image, surface of the area being a function of a distance between the pixel and a reference pixel of the image in both dimensions of an image plane, wherein the reference pixel is a projection of a reference point and wherein the surface varies according to a continuous spherical mapping operator that is a function of:
- coordinates of the reference pixel corresponding to a center of a region of interest defined by the continuous spherical mapping operator,
- an angular window around the reference point,
- an angular resolution at the reference pixel,
- an angular resolution at pixels corresponding to border of the angular window.
A method comprising de-projecting a pixel of an image onto an area of a sphere, surface of the area being a function of a distance between the pixel and a reference pixel of the image in both dimensions of an image plane, wherein the reference pixel is a projection of a reference point and wherein the surface varies according to a continuous spherical mapping operator that is a function of:
- coordinates of the reference pixel corresponding to a center of a region of interest defined by the continuous spherical mapping operator,
- an angular window around the reference point,
- an angular resolution at the reference pixel,
- an angular resolution at pixels corresponding to border of the angular window.
A device comprising a processor configured for de-projecting a pixel of an image onto an area of a sphere, surface of the area being a function of a distance between the pixel and a reference pixel of the image in both dimensions of an image plane, wherein the reference pixel is a projection of a reference point and wherein the surface varies according to a continuous spherical mapping operator that is a function of:
- coordinates of the reference pixel corresponding to a center of a region of interest defined by the continuous spherical mapping operator,
- an angular window around the reference point,
- an angular resolution at the reference pixel,
- an angular resolution at pixels corresponding to border of the angular window.
Dependencies are inferred from the claim text.