An image processing apparatus can generate a vector sequence representing each color region of a color image. The image processing apparatus divides the image into plural regions based on attribute information of the image, and extracts region boundary information relating to a boundary line between different regions. The image processing apparatus generates inter-edge point vector data for each boundary connecting a first edge point to a second edge point corresponding to intersections of boundaries between neighboring regions, based on the extracted region boundary information. The image processing apparatus identifies one or more inter-edge point vector data representing a boundary of each divided region based on the generated inter-edge point vector data, and generates individual region vector data.