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;
}
Point calculateShift(InputArray _img0, InputArray _img1)
{
Mat img0 = _img0.getMat();
Mat img1 = _img1.getMat();
CV_Assert(img0.channels() == 1 && img0.type() == img1.type());
CV_Assert(img0.size() == img0.size());
int maxlevel = static_cast<int>(log((double)max(img0.rows, img0.cols)) / log(2.0)) - 1;
maxlevel = min(maxlevel, max_bits - 1);
std::vector<Mat> pyr0;
std::vector<Mat> pyr1;
buildPyr(img0, pyr0, maxlevel);
buildPyr(img1, pyr1, maxlevel);
Point shift(0, 0);
for(int level = maxlevel; level >= 0; level--) {
shift *= 2;
Mat tb1, tb2, eb1, eb2;
computeBitmaps(pyr0[level], tb1, eb1);
computeBitmaps(pyr1[level], tb2, eb2);
int min_err = (int)pyr0[level].total();
Point new_shift(shift);
for(int i = -1; i <= 1; i++) {
for(int j = -1; j <= 1; j++) {
Point test_shift = shift + Point(i, j);
Mat shifted_tb2, shifted_eb2, diff;
shiftMat(tb2, shifted_tb2, test_shift);
shiftMat(eb2, shifted_eb2, test_shift);
bitwise_xor(tb1, shifted_tb2, diff);
bitwise_and(diff, eb1, diff);
bitwise_and(diff, shifted_eb2, diff);
int err = countNonZero(diff);
if(err < min_err) {
new_shift = test_shift;
min_err = err;
}
}
}
shift = new_shift;
}
return shift;
}
