Shape from shading is an important research domain in the computer vision

this algorithm can be applied to fabric surface reconstruction

which is the base to evaluate fabric wrinkle degree objectively. A new algorithm of shape from shading is proposed in detail in this paper

including realization process and calculation method. According to reflection map equation

restrict qualification should be added to real image because of noise affection

the whole error expression can be gotten by using restrict qualification

for increasing iteration convergence

reflection map equation is linearization and boundary condition is taken initial value

the 3D surface shape can be gotten through iteration calculation. In detail

firstly

the synthetic image is selected to do iterate calculation

which can acquire the reconstructed image exactly

and then the real replica is imported to test this method

the precision of result is very high; this algorithm can be applied to reconstruct the shape of real fabric

the wrinkle feature parameters are proposed in this paper

which can be extracted from the 3D contour data of surface shape. The result shows that these feature values can reflect the fabric wrinkle degree from different sides; it has closely linear correlation between feature values and fabric wrinkle degree

which can be used to assess fabric wrinkle degree objectively.