static void computeOffset(cv::Mat img1, cv::Mat img2, int d, cv::Point& _off)
{
cv::Point offset;
cv::Size size1 = img1.size(), size2 = img2.size();
if ((size1.width > 2 && size1.height > 2) &&
(size2.width > 2 && size2.height > 2) &&
(d < 16)) {
cv::Mat tmp1, tmp2;
cv::resize(img1, tmp1, cv::Size(), 0.5f, 0.5f);
cv::resize(img2, tmp2, cv::Size(), 0.5f, 0.5f);
computeOffset(tmp1, tmp2, d+1, offset);
offset.x *= 2, offset.y *= 2;
} else {
offset.x = 0, offset.y = 0;
}
cv::Point result;
cv::Mat tb1, tb2, eb1, eb2;
computeBitmaps(img1, tb1, eb1);
computeBitmaps(img2, tb2, eb2);
cv::Rect bound1(cv::Point(0,0), size1);
cv::Rect bound2(cv::Point(0,0), size2);
int min_err = (bound1 & bound2).area();
for (int dx = -1; dx <= 1; ++dx) {
for (int dy = -1; dy <= 1; ++dy) {
cv::Point displace = offset + cv::Point(dx,dy);
cv::Rect frame = bound1 & (bound2 + displace);
cv::Rect shift = bound2 & (bound1 - displace);
// ROIs
cv::Mat framed_tb1(tb1, frame);
cv::Mat framed_eb1(eb1, frame);
cv::Mat shifted_tb2(tb2, shift);
cv::Mat shifted_eb2(eb2, shift);
//
cv::Mat tmp1, tmp2;
cv::bitwise_xor(framed_tb1, shifted_tb2, tmp1);
cv::bitwise_and(tmp1, framed_eb1, tmp2);
cv::bitwise_and(shifted_eb2, tmp2, tmp1);
//
int err = (int)cv::sum(tmp1)[0];
if (dx == 0 && dy == 0)
err -= 1;
if (err < min_err) {
result = displace;
min_err = err;
}
}
}
_off = result;
}
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
};