Patent attributes
An image compression apparatus has a connected pixel extraction unit for extracting drawn connected pixels contained in the color document image, a foreground/background image classification unit for classifying connected pixel groups extracted by the compressed connected pixel extraction unit as a foreground image or a background image, a color-by-color-based binary image generation unit for generating binary image data for each color from information on the color of the connected pixel groups classified as a foreground image, a foreground image compression unit for compressing the color binary image data generated by the compressed color-by-color-based binary image generation unit, a background image generation unit for generating a background image, a background image compression unit for compressing the background image generated by the compressed background image generation unit, and a compressed image data generation unit for combining the foreground image data compressed by the foreground image compression unit with the background image data compressed by the background image compression unit into a single piece of compression image data.