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  2. Radon transform - Wikipedia

    en.wikipedia.org/wiki/Radon_transform

    Radon transform. Maps f on the (x, y)-domain to Rf on the (α, s)-domain.. In mathematics, the Radon transform is the integral transform which takes a function f defined on the plane to a function Rf defined on the (two-dimensional) space of lines in the plane, whose value at a particular line is equal to the line integral of the function over that line.

  3. Tomographic reconstruction - Wikipedia

    en.wikipedia.org/wiki/Tomographic_reconstruction

    Using the inverse Fourier transform, the inverse Radon transform formula can be easily derived. (,) = ... The figure was generated by using MATLAB. ...

  4. Projection-slice theorem - Wikipedia

    en.wikipedia.org/wiki/Projection-slice_theorem

    Take a two-dimensional function f(r), project (e.g. using the Radon transform) it onto a (one-dimensional) line, and do a Fourier transform of that projection. Take that same function, but do a two-dimensional Fourier transform first, and then slice it through its origin, which is parallel to the projection line. In operator terms, if

  5. Fourier transform - Wikipedia

    en.wikipedia.org/wiki/Fourier_transform

    In mathematics, the Fourier transform (FT) is an integral transform that takes a function as input and outputs another function that describes the extent to which various frequencies are present in the original function. The output of the transform is a complex-valued function of frequency.

  6. Mojette transform - Wikipedia

    en.wikipedia.org/wiki/Mojette_Transform

    The Mojette transform is an application of discrete geometry. More specifically, it is a discrete and exact version of the Radon transform, thus a projection operator. The IRCCyN laboratory - UMR CNRS 6597 in Nantes, France has been developing it since 1994. The first characteristic of the Mojette transform is using only additions and subtractions.

  7. Fractional Fourier transform - Wikipedia

    en.wikipedia.org/wiki/Fractional_Fourier_transform

    In mathematics, in the area of harmonic analysis, the fractional Fourier transform (FRFT) is a family of linear transformations generalizing the Fourier transform.It can be thought of as the Fourier transform to the n-th power, where n need not be an integer — thus, it can transform a function to any intermediate domain between time and frequency.

  8. Rectangular function - Wikipedia

    en.wikipedia.org/wiki/Rectangular_function

    Plot of normalized ⁡ function (i.e. ⁡ ()) with its spectral frequency components.. The unitary Fourier transforms of the rectangular function are [2] ⁡ = ⁡ = ⁡ (), using ordinary frequency f, where is the normalized form [10] of the sinc function and ⁡ = ⁡ (/) / = ⁡ (/), using angular frequency , where is the unnormalized form of the sinc function.

  9. Abel transform - Wikipedia

    en.wikipedia.org/wiki/Abel_transform

    The Abel transform is one member of the FHA cycle of integral operators. For example, in two dimensions, if we define A as the Abel transform operator, F as the Fourier transform operator and H as the zeroth-order Hankel transform operator, then the special case of the projection-slice theorem for circularly symmetric functions states that