Sub-pixel color edge detection by using binary quaternion-moment-preserving thresholding technique

This paper presents a new moment-preserving thresholding technique, called the binary quaternion-moment-preserving (BQMP) thresholding, for color image data. Based on representing color data by the quaternions, the statistical parameters of color data can be expressed through the definition of quaternion moments. Analytical formulas of the BQMP thresholding can thus be determined by using the algebra of the quaternions. The computation time for the BQMP thresholding is of order of data size. Employing the BQMP thresholding, quaternion-moment-based operators are designed for the applications of color image processing, such as color image compression and subpixel color edge detection. The experimental results showed that the proposed operators can be used as a tool for color image processing.