Area filling algorithm based on four-way scan mode

The invention belongs to the digital image processing technology field, concretely relating to an area filling algorithm based on a four-way scan mode. Through setting a specific edge point in a binary edge image as a starting point, the edge image is subjected to scan in four directions, a closed area enclosed by closed edge lines is screened, and other noises in an unclosed area and the edge image are effectively eliminated. A realization mode of the invention is simple, no complex operation is needed, and the closed area can be accurately screened from the complex edge image. The whole algorithm is operated automatically with no need of human intervention and without recursion operation, and is very suitable for parallel realization. Extraction of the closed area in the complex changeable edge image can not be realized in other area filling algorithms, but according to the invention, the extraction of the closed area in the complex changeable edge image is realized. Simultaneously, compared with the other