An image signal processing apparatus having three processing portions. A first processing portion generates a motion class that corresponds to a target position in an output image signal based on an input image signal. A second portion generates a space class corresponding to the target position based on the input image signal and synthesizes the space class and the motion class to generate one class. A third portion selects multiple items of pixel data positioned in a periphery of this target position based on the input image signal and generates pixel data of the target position in the output image signal according to an estimate equation using the multiple items of pixel data and coefficient data corresponding to the class. These processing portions are respectively constituted of integrated circuits (ICs) having the same configuration. These ICs have first and second functional blocks. Each of the functional blocks changes its functionality according to setting.