Quaternion and Octonion color image processing with MATLAB Complex and hypercomplex numbers Octonion numbers Quaternions and color images Color images as 2 D gray scale images 1 D quaternion and octonion discrete Fourier transforms 2 D quaternion and octonion discrete Fourier transforms Color image enhancement and QDFT Gradients face recognition visualization and quaternions Color image restoration and QDFT Color image processing has involved much interest in the recent years. The use of color in image processing is motivated by the facts that 1) the human eyes can discern thousands of colors and image processing is used both for human interaction and computer interpretation; 2) the color image comprises more information than the gray level image; 3) the color features are robust to several image processing procedures (for example to the translation and rotation of the regions of interest); 4) the color features are efficiently used in many vision tasks including object recognition and tracking image segmentation and retrieval image registration etc.; 5) the color is necessary in many real life applications such as visual communications multimedia systems fashion and food industries computer vision entertainment consumer electronics production printing and proofing digital photography biometrics digital artwork reproduction industrial inspection and biomedical applications. Finally the enormous number of color images that constantly are uploaded into Internet require new approaches and challenges of big visual media creation retrieval processing and applications. It also gives us new opportunities to create a number of big visual data driven applications. Three independent quantities are used to describe any particular color; the human eyes are seen all colors as variable combinations of primary colors of red green and blue. Many methods of the modern color image processing are based on dealing out each primary color