colorize3_poisson.py 文件源码

def drop_shadow(self, alpha, theta, shift, size, op=0.80):
        """
        alpha : alpha layer whose shadow need to be cast
        theta : [0,2pi] -- the shadow direction
        shift : shift in pixels of the shadow
        size  : size of the GaussianBlur filter
        op    : opacity of the shadow (multiplying factor)

        @return : alpha of the shadow layer
                  (it is assumed that the color is black/white)
        """
        if size%2==0:
            size -= 1
            size = max(1,size)
        shadow = cv.GaussianBlur(alpha,(size,size),0)
        [dx,dy] = shift * np.array([-np.sin(theta), np.cos(theta)])
        shadow = op*sii.shift(shadow, shift=[dx,dy],mode='constant',cval=0)
        return shadow.astype('uint8')