void Align::align(void)
{
std::cout << "Registering input images..." << std::endl;
// Vector containing the shift values in x and y between images i and i+1
std::vector<std::vector<int>> consecutiveShifts(images->size()-1, std::vector<int>(2,0));
// Compute the offsets between one image and the next one in the list
for (unsigned int i=0; i<images->size()-1; i++)
{
// Calculate the consecutive shifts in x and y between the current image and the next one
std::cout << "Calculating shift between image " << i << " and image " << i+1 << "..." << std::endl;
getExpShift((*images)[i], (*images)[i+1], shift_bits, consecutiveShifts[i]);
#ifdef DEBUG
std::cout << "Shift between image " << i << " and image " << i+1 << ":\n"
<< "\tx: " << consecutiveShifts[i][0] << "\n"
<< "\ty: " << consecutiveShifts[i][1] << std::endl;
#endif
} // end for all image pairs
// Build a matrix of offsets from any image to any other one.
updateRelativeShifts(consecutiveShifts);
// Use this matrix to crop the images so that they
// have the same size and are correctly registered
cropImages();
};
void getExpShift(const Array2D8u& img1, const int median1,
const Array2D8u& img2, const int median2,
const int noise, const int shift_bits,
int &shift_x, int &shift_y)
{
assert(img1.getCols() == img2.getCols());
assert(img1.getRows() == img2.getRows());
int curr_x = 0;
int curr_y = 0;
if (shift_bits > 0)
{
Array2D8u img1small(img1.getCols()/2, img1.getRows()/2);
Array2D8u img2small(img2.getCols()/2, img2.getRows()/2);
pfs::resize(img1, img1small);
pfs::resize(img2, img2small);
getExpShift(img1small, median1, img2small, median2,
noise, shift_bits-1, curr_x, curr_y);
curr_x *= 2;
curr_y *= 2;
}
Array2Db img1threshold(img1.getCols(), img1.getRows());
Array2Db img1mask(img1.getCols(), img1.getRows());
Array2Db img2threshold(img2.getCols(), img2.getRows());
Array2Db img2mask(img2.getCols(), img2.getRows());
setThreshold(img1, median1, noise, img1threshold, img1mask);
setThreshold(img2, median2, noise, img2threshold, img2mask);
Array2Db img2_shifted(img2.getCols(), img2.getRows());
Array2Db img2mask_shifted(img2.getCols(), img2.getRows());
int minerr = img1.size();
for (int i = -1; i <= 1; i++)
{
for (int j = -1; j <= 1; j++)
{
int dx = curr_x + i;
int dy = curr_y + j;
pfs::shift(img2threshold, dx, dy, img2_shifted);
pfs::shift(img2mask, dx, dy, img2mask_shifted);
long err = XORimages(img1threshold, img1mask, img2_shifted, img2mask_shifted);
if ( err < minerr ) {
minerr = err;
shift_x = dx;
shift_y = dy;
}
}
}
PRINT_DEBUG("getExpShift::Level " << shift_bits << " shift (" << shift_x << "," << shift_y << ")");
}
void Align::getExpShift(const Image& img1, const Image& img2, int shift_bits, std::vector<int>& shift_ret)
{
std::vector<int> cur_shift(2, 0);
int i, j;
if (shift_bits > 0)
{
Image sml_img1 = img1.shrink2();
Image sml_img2 = img2.shrink2();
getExpShift(sml_img1, sml_img2, shift_bits-1, cur_shift);
cur_shift[0] *= 2;
cur_shift[1] *= 2;
}
else
{
cur_shift[0] = cur_shift[1] = 0;
}
Bitmap tb1; img1.computeThresholdBitmap(tb1);
Bitmap eb1; img1.computeExclusionBitmap(eb1);
Bitmap tb2; img2.computeThresholdBitmap(tb2);
Bitmap eb2; img2.computeExclusionBitmap(eb2);
int min_err = img1.rows * img1.cols;
for (i=-1; i<=1; i++)
{
for (j=-1; j<=1; j++)
{
if (min_err > 0)
{
int xs = cur_shift[0] + i;
int ys = cur_shift[1] + j;
Bitmap shifted_tb2(img1.rows, img1.cols);
Bitmap shifted_eb2(img1.rows, img1.cols);
Bitmap diff_b(img1.rows, img1.cols);
bitmapShift(tb2, xs, ys, shifted_tb2);
bitmapShift(eb2, xs, ys, shifted_eb2);
bitmapXOR(tb1, shifted_tb2, diff_b);
bitmapAND(diff_b, eb1, diff_b);
bitmapAND(diff_b, shifted_eb2, diff_b);
int err = diff_b.total();
if (err < min_err)
{
shift_ret[0] = xs;
shift_ret[1] = ys;
min_err = err;
}
}
} // end for j
} // end for i
};
void mtbalign(const pfs::Frame& image1, const pfs::Frame& image2,
const double quantile, const int noise, const int shift_bits,
int &shift_x, int &shift_y)
{
Array2D8u img1lum;
Array2D8u img2lum;
int median1 = getLum(image1, img1lum, quantile);
int median2 = getLum(image2, img2lum, quantile);
PRINT_DEBUG("align::medians, image 1: " << median1 << ", image 2: " << median2);
getExpShift(img1lum, median1,
img2lum, median2,
noise, shift_bits, shift_x, shift_y);
PRINT_DEBUG("align::done, final shift is (" << shift_x << "," << shift_y <<")");
}
