IMAGE CONVERTER AND IMAGE CONVERTING METHOD
First Claim
1. An image converter for performing processes of cutting out a part of a distorted circular image photographed by use of a fisheye lens and converting it into a planar regular image, the image converter comprising:
- a distorted circular image storage unit which stores a distorted circular image constituted with aggregates of pixels arranged at a position indicated by coordinates (x, y) on a two-dimensional XY orthogonal coordinate system and having a radius R taking an origin O of the XY coordinate system as a center;
a planar regular image storage unit which stores a planar regular image constituted with aggregates of pixels arranged at a position indicated by coordinates (u, v) on a two-dimensional UV orthogonal coordinate system;
a distorted circular image display unit which displays the distorted circular image stored in the distorted circular image storage unit;
an instruction input unit which inputs a position of a cut-out center point P and a cut-out orientation on the distorted circular image displayed on the basis of instructions by a user;
an intersecting point operation unit which, when a virtual sphere having a radius R taking the origin O as a center is defined in a three-dimensional XYZ orthogonal coordinate system including the two-dimensional XY orthogonal coordinate system, determines position coordinates (x0, y0, z0) of an intersecting point G between a straight line passing through the cut-out center point P and parallel with a Z axis and the virtual sphere;
an angle determining unit which determines on the basis of the cut-out orientation a planar inclination angle φ
given as an angle formed between a vector U facing an U axis of the two-dimensional UV orthogonal coordinate system which is defined on a tangent plane in contact with the virtual sphere at the intersecting point G and a vector X facing an X axis of the two-dimensional XY orthogonal coordinate system; and
a transformation unit which makes correspondence between coordinates (u, v) and coordinates (x, y) by utilizing transformation equations based on an orthogonal projection method including the position coordinates (x0, y0, z0) and the planar inclination angle φ
as parameters, determines a pixel value of a pixel on the planar regular image arranged at a position indicated by coordinates (u, v) on the basis of a pixel value of a reference pixel on the distorted circular image arranged at a position indicated by corresponding coordinates (x, y), and forms the planar regular image with regard to a partial image cut out from the distorted circular image in an orientation indicated by the planar inclination angle φ
taking the cut-out center point P as a center, so that the thus formed planar regular image is stored in the planar regular image storage unit.
1 Assignment
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Accused Products
Abstract
On conversion of a distorted circular image photographed by use of a fisheye lens to a planar regular image, parameter setting is performed by a user'"'"'s intuitive manipulation to relieve the operation load. A dome-shaped virtual sphere H is defined on a distorted circular image S on the XY plane, and a user is allowed to designate a cut-out center point P (x0, y0) and an auxiliary point Q (x1, y1) on the distorted circular image S. An intersecting point G (x0, y0, z0) immediately above the point P is determined, and a UV plane is defined on a tangent plane S2 with respect to the virtual sphere H. An angle φ formed between the U axis and the X axis is determined on the basis of an angle θ formed between a reference straight line J passing through two points P, Q and the X axis. Transformation equations based on the orthogonal projection method including the coordinate values x0, y0, z0 and the angle φ as parameters are utilized to allow the coordinates (u, v) to correspond to coordinates (x, y), a distance between the two points P, Q is given as a conversion magnification m, thereby a part in the vicinity of the point P of the distorted circular image S is converted to a plane regular image on the UV plane.
20 Citations
26 Claims
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1. An image converter for performing processes of cutting out a part of a distorted circular image photographed by use of a fisheye lens and converting it into a planar regular image, the image converter comprising:
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a distorted circular image storage unit which stores a distorted circular image constituted with aggregates of pixels arranged at a position indicated by coordinates (x, y) on a two-dimensional XY orthogonal coordinate system and having a radius R taking an origin O of the XY coordinate system as a center; a planar regular image storage unit which stores a planar regular image constituted with aggregates of pixels arranged at a position indicated by coordinates (u, v) on a two-dimensional UV orthogonal coordinate system; a distorted circular image display unit which displays the distorted circular image stored in the distorted circular image storage unit; an instruction input unit which inputs a position of a cut-out center point P and a cut-out orientation on the distorted circular image displayed on the basis of instructions by a user; an intersecting point operation unit which, when a virtual sphere having a radius R taking the origin O as a center is defined in a three-dimensional XYZ orthogonal coordinate system including the two-dimensional XY orthogonal coordinate system, determines position coordinates (x0, y0, z0) of an intersecting point G between a straight line passing through the cut-out center point P and parallel with a Z axis and the virtual sphere; an angle determining unit which determines on the basis of the cut-out orientation a planar inclination angle φ
given as an angle formed between a vector U facing an U axis of the two-dimensional UV orthogonal coordinate system which is defined on a tangent plane in contact with the virtual sphere at the intersecting point G and a vector X facing an X axis of the two-dimensional XY orthogonal coordinate system; anda transformation unit which makes correspondence between coordinates (u, v) and coordinates (x, y) by utilizing transformation equations based on an orthogonal projection method including the position coordinates (x0, y0, z0) and the planar inclination angle φ
as parameters, determines a pixel value of a pixel on the planar regular image arranged at a position indicated by coordinates (u, v) on the basis of a pixel value of a reference pixel on the distorted circular image arranged at a position indicated by corresponding coordinates (x, y), and forms the planar regular image with regard to a partial image cut out from the distorted circular image in an orientation indicated by the planar inclination angle φ
taking the cut-out center point P as a center, so that the thus formed planar regular image is stored in the planar regular image storage unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. An image converter for performing processes of cutting out a part of a distorted circular image photographed by use of a fisheye lens and converting it into a planar regular image, the image converter comprising:
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a distorted circular image storage unit which stores a distorted circular image constituted with aggregates of pixels arranged at a position indicated by coordinates (x, y) on a two-dimensional XY orthogonal coordinate system; a planar regular image storage unit which stores a planar regular image constituted with aggregates of pixels arranged at a position indicated by coordinates (u, v) on a two-dimensional UV orthogonal coordinate system; a distorted circular image display unit which displays the distorted circular image stored in the distorted circular image storage unit; an instruction input unit which inputs positions of two points, a cut-out center point P and an auxiliary point Q on the basis of instructions given by a user on the distorted circular image displayed, and recognizes a straight line connecting the cut-out center point P with the auxiliary point Q as a reference straight line J, and a numerical value given as m=k/d (k is a predetermined proportional constant) as a conversion magnification m on the basis of a distance d between the cut-out center point P and the auxiliary point Q; and a transformation unit which determines a pixel value of a pixel on the planar regular image arranged at a position indicated by coordinates (u, v) on the basis of a pixel value of a reference pixel on the distorted circular image arranged at a position indicated by corresponding coordinates (x, y) by utilizing a transformation equation for allowing the coordinates (u, v) to correspond to the coordinates (x, y), and performs an operation for forming a planar regular image subjected to scaling on the basis of the conversion magnification m with regard to a partial image cut out from the distorted circular image to an orientation in accordance with the reference straight line J taking the cut-out center point P as a center, so that the thus formed planar regular image is stored in the planar regular image storage unit.
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22. An image converter for performing processes of cutting out a part of a distorted circular image photographed by use of a fisheye lens and converting it into a planar regular image, the image converter comprising:
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a distorted circular image storage unit which stores a distorted circular image constituted with aggregates of pixels arranged at a position indicated by coordinates (x, y) on a two-dimensional XY orthogonal coordinate system; a planar regular image storage unit which stores a planar regular image constituted with aggregates of pixels arranged at a position indicated by coordinates (u, v) on a two-dimensional UV orthogonal coordinate system; a distorted circular image display unit which displays the distorted circular image stored in the distorted circular image storage unit; an instruction input unit which inputs an angle θ
defined as an angle formed between a reference straight line J and the X axis and a conversion magnification m on the basis of instructions given by a user on a input screen, and a position of a cut-out center point P on the basis of instructions given by the user on the distorted circular image displayed; anda transformation unit which determines a pixel value of a pixel on the planar regular image arranged at a position indicated by coordinates (u, v) on the basis of a pixel value of a reference pixel on the distorted circular image arranged at a position indicated by corresponding coordinates (x, y) by utilizing a transformation equation for allowing the coordinates (u, v) to correspond to the coordinates (x, y), and performs an operation for forming a planar regular image subjected to scaling on the basis of the conversion magnification m with regard to a partial image cut out from the distorted circular image to an orientation in accordance with the reference straight line J taking the cut-out center point P as a center, so that the thus formed planar regular image is stored in the planar regular image storage unit.
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23. An image converting method for performing processes of cutting out a part of a distorted circular image photographed by use of a fisheye lens and converting it into a planar regular image, the image converting method which allows a computer or an electronic circuit to perform the following steps:
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storing in a distorted circular image storage unit a distorted circular image constituted with aggregates of pixels arranged at a position indicated by coordinates (x, y) on a two-dimensional XY orthogonal coordinate system and having a radius R taking an origin O of the XY coordinate system as a center; displaying on a display the distorted circular image stored in the distorted circular image storage unit; entering position and cut-out orientation of a cut-out center point P on the distorted circular image displayed on the display on the basis of instructions by a user; determining position coordinates (x0, y0, z0) of an intersecting point G between a straight line passing through the cut-out center point P and parallel with a Z axis and a virtual sphere, by defining a virtual sphere having the radius R taking the origin O as a center in a three-dimensional XYZ orthogonal coordinate system including the two-dimensional XY orthogonal coordinate system; determining on the basis of the cut-out orientation a planar inclination angle φ
given as an angle formed between a vector U facing a direction of an U axis of a two-dimensional UV orthogonal coordinate system to be defined on a tangent plane in contact with the virtual sphere on the intersecting point G and a vector X facing a direction of an X axis of the two-dimensional XY orthogonal coordinate system; andperforming operation for forming a planar regular image with regard to a partial image cut out from the distorted circular image to an orientation indicated by the planar inclination angle φ
taking the cut-out center point P as a center by utilizing transformation equations based on an orthogonal projection method including the position coordinates (x0, y0, z0) and the planar inclination angle φ
as parameters to allow coordinates (u, v) to correspond to coordinates (x, y), and determining a pixel value of each pixel on the planar regular image constituted with aggregates of pixels arranged at a position indicated by the coordinates (u, v) on the basis of a pixel value of a reference pixel on the distorted circular image arranged at a position indicated by the corresponding coordinates (x, y). - View Dependent Claims (24, 25, 26)
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Specification