Image processing method and apparatus suitable for both high- resolution and low-resolution image data

摘要

An image processing apparatus makes it possible to efficiently use memories, and to output an image having a high picture quality and a high resolution. The apparatus also makes it possible to reproduce particularly edge portions of an image having a relatively low resolution wherein a plurality of bits are allocated per picture element, with a high resolution. The apparatus further makes it possible to reproduce an image having a high resolution represented by one bit per picture element as an image represented by a plurality of bits per picture element. The apparatus processes a color image obtained by synthesizing a photograph and another photograph, or a photograph and characters with a small memory capacity, and outputs an image having a high quality. That is, the apparatus comprises a memory for storing character/figure images having a high resolution and a small amount of information for one picture element, a memory for storing photographic images having a low resolution and a large amount of information per picture element, and a memory for storing control data for controlling the above-described two kinds of images. An image output having a high picture quality can be obtained with a small amount of information by effectively utilizing features of the above- described two kinds of images. It is thereby possible to reduce the number of devices required for storing information, and therefore to reduce cost. It is also possible to minimize deterioration in picture quality caused by reducing the amount of information.