Image processing apparatus and processing method

摘要

When an image size is changed by using a linear interpolating process, a picture quality is improved so as not to overlap the position of an original signal and the position of an interpolation signal. An interpolation interval Vdp which is derived from an original image and an image size after the conversion is stored into a register of an input side and is accumulated and added by an adder from a register of an output side through a selector. A predetermined calculation is performed and an offset value q0 is obtained in a circuit. The value q0 is selected by the selector and the register of the output side is initialized for a vertical blanking period. Thus, a value ( delta +nVdp) in which the value q0 was added to the accumulation value of Vdp is derived. On the basis of the value ( delta +nVdp), a read address (n) of the original image and linear interpolation coefficients qn1 and qn2 are obtained. A similar process is also executed for the horizonal direction and an address (m) and coefficients pn1 and pn2 are obtained. A proper offset value is added to the interpolating position and the picture quality can be improved without overlapping the original signal and the interpolating position.