High-resolution satellite image provides abundant shape structure and texture information of landscape objects and it becomes important data source in field of city research. Building is principle part of city zone. Vector information of building profile holds vital application value in city research. The vectorization for the dot matrix image of binary is an important work in image processing. Existing vectorization methods are not good at extracting building profile information. This paper describes a new vectorization approach based on corners detection and positioning for the vectorization extraction of rectangle building. After automatically extracting binary image of building profile

the approach establishes combination way of boundary dots grouping by basal point

then adopts piecewise linear fitting by least-square algorithm

in which the key step is how to accurately detect group of boundary dots joining in fitting. The experimental results show that the approach is much fast in vectorization of rectangle building with robustness and higher precision.