Classification of color textures by Gabor filtering
Machine Graphics & Vision International Journal - Special issue on latest results in colour image processing and applications
Spatial and spectral quaternionic approaches for colour images
Computer Vision and Image Understanding
Fractional quaternion Fourier transform, convolution and correlation
Signal Processing
An uncertainty principle for quaternion Fourier transform
Computers & Mathematics with Applications
The monogenic wavelet transform
IEEE Transactions on Signal Processing
Local quaternion Fourier transform and color image texture analysis
Signal Processing
IEEE Transactions on Image Processing
Quaternion Fourier-Mellin moments for color images
Pattern Recognition
Quaternion multiplier inspired by the lifting implementation of plane rotations
IEEE Transactions on Circuits and Systems Part I: Regular Papers
The trinion Fourier transform of color images
Signal Processing
Reliable ear identification using 2-D quadrature filters
Pattern Recognition Letters
A robust blind color image watermarking in quaternion Fourier transform domain
Journal of Systems and Software
Convolution Products for Hypercomplex Fourier Transforms
Journal of Mathematical Imaging and Vision
Full 4-D quaternion discrete Fourier transform based watermarking for color images
Digital Signal Processing
Hi-index | 35.69 |
The concepts of quaternion Fourier transform (QFT), quaternion convolution (QCV), and quaternion correlation, which are based on quaternion algebra, have been found to be useful for color image processing. However, the necessary computational algorithms and their complexity still need some attention. We develop efficient algorithms for QFT, QCV, and quaternion correlation. The conventional complex two-dimensional (2-D) Fourier transform (FT) is used to implement these quaternion operations very efficiently. With these algorithms, we only need two complex 2-D FTs to implement a QFT, six complex 2-D FTs to implement a one-side QCV or a quaternion correlation and 12 complex 2-D FTs to implement a two-side QCV, and the efficiency of these quaternion operations is much improved. Meanwhile, we also discuss two additional topics. The first one is about how to use QFT and QCV for quaternion linear time-invariant (QLTI) system analysis. This topic is important for quaternion filter design and color image processing. Besides, we also develop the spectrum-product QCV. It is an improvement of the conventional form of QCV. For any arbitrary input functions, it always corresponds to the product operation in the frequency domain. It is very useful for quaternion filter design