Linear Correction and Matching Method for 3D Line Structure Reconstruction

Algorithm 1

Steps of constructing gradient gravitational map.

	Input: image .
Output: gradient gravitational map
(1)	Calculate the edge map of image and calculate the size of
(2)	Solve the extended gradient map of
(3)	Construct a 3D matrix called , where and are and coordinates, respectively. Fill in with and according to the above method.
(4)	Calculate the gravitational value at each location:
m Exit = true
while (mExit)
for i = 1:M
for j = 1:N
{
mExit = false;
if (GM (1, i, j)! = 0
{
mExit = true;
for kx = −1 : 1
for ky = −1 : 1
if (GM (1, i + kx, j + ky) = 0
{
if gradient direction = = 45°
draw a circle centered on the current position,
and according to the edge pixels that intersect
first to fill in
GM (1, i + kx, j + ky) and GM (2, i + kx, j + ky);
else
according to the EGM (i + kx + ky); }
}
}
(5)	Return