Panoramic image mapping method

A panoramic image mapping method to map a spherical surface corresponding to panoramic image or video A into a two-dimensional plane image or video B, comprising:

• first, dividing the spherical surface into three areas based on the latitudes of the spherical surface, denoted as Area I, Area II, and Area III, respectively;
• mapping the three areas to a square plane I′, a rectangular plane II′, and a square plane III′, respectively;
• then, splicing the planes I′, II′ and III′ into a plane, wherein the resulting plane is the two-dimensional image or video B;
• wherein Area I corresponds to the area with a latitude of −90°˜Z1 on the spherical surface, Area II corresponds to the area with a latitude of Z1˜Z2 on the spherical surface, and Area III corresponds to the area with a latitude of Z2˜90° on the spherical surface;
• the values of the parameters Z1, Z2 are autonomously set and satisfy the condition:
• −90°≤Z1≤Z2≤90°;
• the square plane I′ has a resolution of WI×WI, the rectangular plane II′ has a resolution of WII×HII, and the square plane III′ has a resolution of WIII×WIII;
• the values of the parameters WI, WII, HII, WIII are autonomously set;
• the mapping method comprises steps of:
• 1) for each pixel point in the square plane I′, computing its corresponding spherical coordinates (longitudes and latitudes) based on its coordinates (X, Y) in the plane I′;
• then, taking the pixel value at a corresponding position on the spherical surface (or obtaining a corresponding pixel value of a surrounding pixel by interpolation) as the pixel value of the pixel point (X, Y) in the plane I′, wherein the computing the corresponding spherical coordinates Coordinate based on the coordinates (X, Y) of the pixel point in the plane I′ comprises steps of:
• 1.1) computing the vertical distance and the horizontal distance from the point to the square plane I′, and taking the larger one, denoted as m;
• 1.2) the square plane I′ may comprise a plurality of concentric squares;
• in this step, the distance from the point to the 0th point on the concentric square where the point is located, denoted as n;
• wherein the position of the nth point may be randomly selected;
• computing the distance from the pixel point to the nth point on the concentric square where the pixel point is located in the clockwise or counterclockwise manner;
• 1.3) computing the latitude and the longitude corresponding to the point with coordinates (X, Y) in the square plane I′ based on n and m, obtaining the corresponding coordinates Coordinate on the spherical surface;
• 2) for each pixel point in the rectangular plane II′, computing its corresponding spherical coordinates, including longitudes and latitudes based on its coordinates (X, Y) in the plane II′;
• then, taking the pixel value at a corresponding position on the spherical surface, or obtaining a corresponding pixel value of a surrounding pixel by interpolation, as the pixel value of the pixel point (X, Y) in the plane II′.
• 3) for each pixel point in the square plane III′, computing its corresponding spherical coordinates, including longitudes and latitudes) based on its coordinates (X, Y) in the plane III′;
• then, taking the pixel value at a corresponding position on the spherical surface (or obtaining a corresponding pixel value of a surrounding pixel by interpolation) as the pixel value of the pixel point (X, Y) in the plane I′, wherein the computing the corresponding spherical coordinates Coordinate based on the coordinates (X, Y) of the pixel point in the plane III′ comprises steps of:
• 3.1) computing the vertical distance and the horizontal distance from the point to the square plane III′, and taking the larger one, denoted as m;
• 3.2) the square plane III′ may comprise a plurality of concentric squares;
• the distance from the point to the 0th point on the concentric square where the point is located, denoted as n;
• wherein the position of the nth point may be randomly selected;
• 3.3) computing the latitude and the longitude corresponding to the point with coordinates (X, Y) in the square plane III′ based on n and m;
• 4) splicing the planes I′, II′, and III′ into a plane based on the value of WI, WII, HII, WIII.