CV 光流场计算1（ area correlation optical flow）

using System;
public class opticalFlow
{
static int[] input1;
static int[] input2;
static int[] output;
int progress;
int width;
int height;
int window;
int displacement;
public void opticalFlow()
{
progress = 0;
}
public void init(int[] input1, int[] input2, int widthIn, int heightIn, int window, int displacement)
{
width = widthIn;
height = heightIn;
this.input1 = input1;
this.input2 = input2;
output = new int[width * height];
this.window = window;
this.displacement = displacement;
}
public int[] process()
{
progress = 0;
// arrays to store the vectors
int[] u = new int[width * height];
int[] v = new int[width * height];
// loop over the image
for (int x1 = (window + displacement + 1); x1 < (width - window - displacement); x1++)
{
progress++;
for (int y1 = (window + displacement + 1); y1 < (height - window - displacement); y1++)
{
int min = 9999999;
int dx = 0;
int dy = 0;
// loop through the displacement area
for (int x2 = (x1 - displacement); x2 < (x1 + displacement); x2++)
{
for (int y2 = (y1 - displacement); y2 < (y1 + displacement); y2++)
{
int sum = 0;
// loop over the window area - (2 * window) + 1
for (int i = -window; i < window; i++)
{
for (int j = -window; j < window; j++)
{
// sum pixel intensity difference squared over the window area
sum += (int)Math.pow((double)((input1[(x1 + i) + (y1 + j) * width] & 0xff) - (input2[(x2 + i) + (y2 + j) * width] & 0xff)), 2);
}
}
if (sum < min)
{
min = sum;
dx = x2 - x1;
dy = y2 - y1;
}
}
}
// set velocity 
u[x1 + y1 * width] = dx;
v[x1 + y1 * width] = dy;
}
}
progress = width;
// we now have the vectors of the optical flow and need to construct a graph
int val;
int step = 5;
for (int x = 0; x < width; x++)
{
for (int y = 0; y < height; y++)
{
if ((x % step != 0 || y % step != 0) || u[x + y * width] == v[x + y * width])
{
val = 255;
output[x + y * width] = 0xff000000 | (int)val << 16 | (int)val << 8 | (int)val;
}
else
{
int size = Math.abs(u[x + y * width] - v[x + y * width]);
int xv = u[x + y * width];
int yv = v[x + y * width];
line(x, y, x + (xv * 2), y + (yv * 2));
}
}
}
return output;
}
public int getProgress()
{
return progress;
}
public void line(int x0, int y0, int x1, int y1)
{
if (x1 > width) x1 = width;
if (x1 < 0) x1 = 0;
if (y1 > height) y1 = height;
if (y1 < 0) y1 = 0;
int dx = x1 - x0;
int dy = y1 - y0;
int val = 0;
output[x0 + y0 * width] = 0xff000000 | (int)val << 16 | (int)val << 8 | (int)val;
if (Math.abs(dx) > Math.abs(dy))
{ // slope < 1
float m = (float)dy / (float)dx; // compute slope
float b = y0 - m * x0;
dx = (dx < 0) ? -1 : 1;
while (x0 != x1)
{
x0 += dx;
output[x0 + Math.round(m * x0 + b) * width] = 0xff000000 | (int)val << 16 | (int)val << 8 | (int)val;
if (val < 250) val += 25;
}
}
else
if (dy != 0)
{ // slope >= 1
float m = (float)dx / (float)dy; // compute slope
float b = x0 - m * y0;
dy = (dy < 0) ? -1 : 1;
while (y0 != y1)
{
y0 += dy;
output[Math.round(m * y0 + b) + y0 * width] = 0xff000000 | (int)val << 16 | (int)val << 8 | (int)val;
if (val < 250) val += 25;
}
}
}