  In the process of projecting the surface of a three-dimensional object onto a
two-dimensional surface, due to the perspective distortion, the image on the
surface of the object will have different degrees of distortion according to
the level of the surface curvature. This paper presents an imprecise method for
flattening this type of distortion on the surface of a regularly curved body.
The main idea of this method is to roughly estimate the gridded surface
subdivision that can be used to describe the surface of the three-dimensional
object through the contour curve of the two-dimensional image of the object.
Then, take each grid block with different sizes and shapes inversely
transformed into a rectangle with exactly the same shape and size. Finally,
each of the same rectangles is splicing and recombining in turn to obtain a
roughly flat rectangle. This paper will introduce and show the specific process
and results of using this method to solve the problem of bending page
flattening, then demonstrate the feasibility and limitations of this method.
