This paper proposes a free-viewpoint imaging method that can be used in a complicated scene such as an office room by using sparsely located cameras. In our method, a free-viewpoint image is generated from multiple image patches obtained by dividing observed images. The quality of the generated image strongly depends on how to divide the observed images. In an incorrect patch in the generated image, the images projected from different cameras differ significantly. With this property, the incorrect patches can be detected. These patches are then re-divided. We demonstrated the effectiveness of our method by generating free-viewpoint images from the real images observed by the cameras in an office room.