CPC H04N 19/60 (2014.11) [G06F 3/013 (2013.01); H04N 19/167 (2014.11)] | 15 Claims |
1. An encoder for encoding images, the encoder comprising at least one processor configured to:
transform a given input pixel of an input image having (x, y) coordinates in a Cartesian coordinate system into a given transformed pixel of a transformed image having (ρ, θ) coordinates in a log-polar coordinate system, using a log-polar transformation in which a radial distance (ρ) of the given transformed pixel is a logarithm of a distance of the given input pixel from an origin in the Cartesian coordinate system, and an angular distance (θ) of the given transformed pixel is a sum of an arctangent of a slope of a line connecting the given input pixel to the origin and a function of the radial distance;
encode the transformed image, by employing a compression algorithm, into an encoded image; and
send the encoded image to a display apparatus for subsequent decoding thereat;
wherein the function of the radial distance is equal to a half of the radial distance.
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