Non-linear and linear method of scale-up or scale-down image resolution conversion

Abstract

A method of non-linear and linear scale-up or scale-down image resolution conversion of digital images. The method is based on using non-linear or linear pixel position control functions relating an output image pixel grid to an input image pixel grid, where resolution of each grid is different. The pixel position control functions enable calculation of real pixel position coordinates of output image pixels, embedded within the input image grid. A connection grid is set up as a graphical representation of using the pixel position control functions. Delta functional differences between real valued position coordinates of output pixels located in the connection grid, and neighbor pixel position coordinates located in the input image grid are defined and calculated. Linear combinations of known values of neighbor pixels in the input image grid, surrounding real valued pixel positions of output image pixels located in the connection grid, are used for calculating a new set of local coefficients for each output image pixel. A new value for each output pixel located in the output image grid is calculated by following a differential prescription for a two dimensional image using n neighbors, featuring an inner multiplication between a vector of the delta functional differences between pixel position coordinates, and a vector of the local coefficients. The method of this invention is applicable to cases of non-linear or linear, scale-up, scale-down, or mixed mode scale-up/scale-down image resolution conversion, and is extendable to a u dimensional image using v neighbors. Moreover, the method of this invention is applicable to interlaced or non-interlaced displays, featuring real time or still, digital color, grayscale, or black and white video images.