Quaternion Fourier and Linear Canonical Inversion Theorems
  The Quaternion Fourier transform (QFT) is one of the key tools in studying color image processing. Indeed, a deep understanding of the QFT has created the color images to be transformed as whole, rather than as color separated component. In addition, understanding the QFT paves the way for understanding other integral transform, such as the Quaternion Fractional Fourier transform (QFRFT), Quaternion linear canonical transform (QLCT) and Quaternion Wigner-Ville distribution. The aim of this paper is twofold: first to provide some of the theoretical background regarding the Quaternion bound variation function. We then apply it to derive the Quaternion Fourier and linear canonical inversion formulas. Secondly, to provide some in tuition for how the Quaternion Fourier and linear canonical inversion theorems work on the absolutely integrable function space. 
Xiao Xiao Hu and Kit Ian Kou
math.CA