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Remove example file

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lhark 2016-06-21 15:52:42 +02:00
parent 9383d6db55
commit f440d0235f
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src/videostab.cpp
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@ -1,258 +0,0 @@
#include <opencv2/opencv.hpp>
#include <iostream>
#include <cassert>
#include <cmath>
#include <fstream>
using namespace std;
using namespace cv;
// This video stablisation smooths the global trajectory using a sliding average window
const int SMOOTHING_RADIUS = 30; // In frames. The larger the more stable the video, but less reactive to sudden panning
const int HORIZONTAL_BORDER_CROP = 20; // In pixels. Crops the border to reduce the black borders from stabilisation being too noticeable.
// 1. Get previous to current frame transformation (dx, dy, da) for all frames
// 2. Accumulate the transformations to get the image trajectory
// 3. Smooth out the trajectory using an averaging window
// 4. Generate new set of previous to current transform, such that the trajectory ends up being the same as the smoothed trajectory
// 5. Apply the new transformation to the video
struct TransformParam
{
TransformParam() {}
TransformParam(double _dx, double _dy, double _da) {
dx = _dx;
dy = _dy;
da = _da;
}
double dx;
double dy;
double da; // angle
};
struct Trajectory
{
Trajectory() {}
Trajectory(double _x, double _y, double _a) {
x = _x;
y = _y;
a = _a;
}
double x;
double y;
double a; // angle
};
int main(int argc, char **argv)
{
if(argc < 2) {
cout << "./VideoStab [video.avi]" << endl;
return 0;
}
// For further analysis
ofstream out_transform("prev_to_cur_transformation.txt");
ofstream out_trajectory("trajectory.txt");
ofstream out_smoothed_trajectory("smoothed_trajectory.txt");
ofstream out_new_transform("new_prev_to_cur_transformation.txt");
VideoCapture cap(argv[1]);
assert(cap.isOpened());
Mat cur, cur_grey;
Mat prev, prev_grey;
cap >> prev;
cvtColor(prev, prev_grey, COLOR_BGR2GRAY);
// Step 1 - Get previous to current frame transformation (dx, dy, da) for all frames
vector <TransformParam> prev_to_cur_transform; // previous to current
int k=1;
int max_frames = cap.get(CV_CAP_PROP_FRAME_COUNT);
Mat last_T;
while(true) {
cap >> cur;
if(cur.data == NULL) {
break;
}
cvtColor(cur, cur_grey, COLOR_BGR2GRAY);
// vector from prev to cur
vector <Point2f> prev_corner, cur_corner;
vector <Point2f> prev_corner2, cur_corner2;
vector <uchar> status;
vector <float> err;
goodFeaturesToTrack(prev_grey, prev_corner, 200, 0.01, 30);
calcOpticalFlowPyrLK(prev_grey, cur_grey, prev_corner, cur_corner, status, err);
// weed out bad matches
for(size_t i=0; i < status.size(); i++) {
if(status[i]) {
prev_corner2.push_back(prev_corner[i]);
cur_corner2.push_back(cur_corner[i]);
}
}
// translation + rotation only
Mat T = estimateRigidTransform(prev_corner2, cur_corner2, false); // false = rigid transform, no scaling/shearing
// in rare cases no transform is found. We'll just use the last known good transform.
if(T.data == NULL) {
last_T.copyTo(T);
}
T.copyTo(last_T);
// decompose T
double dx = T.at<double>(0,2);
double dy = T.at<double>(1,2);
double da = atan2(T.at<double>(1,0), T.at<double>(0,0));
prev_to_cur_transform.push_back(TransformParam(dx, dy, da));
out_transform << k << " " << dx << " " << dy << " " << da << endl;
cur.copyTo(prev);
cur_grey.copyTo(prev_grey);
cout << "Frame: " << k << "/" << max_frames << " - good optical flow: " << prev_corner2.size() << endl;
k++;
}
// Step 2 - Accumulate the transformations to get the image trajectory
// Accumulated frame to frame transform
double a = 0;
double x = 0;
double y = 0;
vector <Trajectory> trajectory; // trajectory at all frames
for(size_t i=0; i < prev_to_cur_transform.size(); i++) {
x += prev_to_cur_transform[i].dx;
y += prev_to_cur_transform[i].dy;
a += prev_to_cur_transform[i].da;
trajectory.push_back(Trajectory(x,y,a));
out_trajectory << (i+1) << " " << x << " " << y << " " << a << endl;
}
// Step 3 - Smooth out the trajectory using an averaging window
vector <Trajectory> smoothed_trajectory; // trajectory at all frames
for(size_t i=0; i < trajectory.size(); i++) {
double sum_x = 0;
double sum_y = 0;
double sum_a = 0;
int count = 0;
for(int j=-SMOOTHING_RADIUS; j <= SMOOTHING_RADIUS; j++) {
if(i+j >= 0 && i+j < trajectory.size()) {
sum_x += trajectory[i+j].x;
sum_y += trajectory[i+j].y;
sum_a += trajectory[i+j].a;
count++;
}
}
double avg_a = sum_a / count;
double avg_x = sum_x / count;
double avg_y = sum_y / count;
smoothed_trajectory.push_back(Trajectory(avg_x, avg_y, avg_a));
out_smoothed_trajectory << (i+1) << " " << avg_x << " " << avg_y << " " << avg_a << endl;
}
// Step 4 - Generate new set of previous to current transform, such that the trajectory ends up being the same as the smoothed trajectory
vector <TransformParam> new_prev_to_cur_transform;
// Accumulated frame to frame transform
a = 0;
x = 0;
y = 0;
for(size_t i=0; i < prev_to_cur_transform.size(); i++) {
x += prev_to_cur_transform[i].dx;
y += prev_to_cur_transform[i].dy;
a += prev_to_cur_transform[i].da;
// target - current
double diff_x = smoothed_trajectory[i].x - x;
double diff_y = smoothed_trajectory[i].y - y;
double diff_a = smoothed_trajectory[i].a - a;
double dx = prev_to_cur_transform[i].dx + diff_x;
double dy = prev_to_cur_transform[i].dy + diff_y;
double da = prev_to_cur_transform[i].da + diff_a;
new_prev_to_cur_transform.push_back(TransformParam(dx, dy, da));
out_new_transform << (i+1) << " " << dx << " " << dy << " " << da << endl;
}
// Step 5 - Apply the new transformation to the video
cap.set(CV_CAP_PROP_POS_FRAMES, 0);
Mat T(2,3,CV_64F);
int vert_border = HORIZONTAL_BORDER_CROP * prev.rows / prev.cols; // get the aspect ratio correct
k=0;
while(k < max_frames-1) { // don't process the very last frame, no valid transform
cap >> cur;
if(cur.data == NULL) {
break;
}
T.at<double>(0,0) = cos(new_prev_to_cur_transform[k].da);
T.at<double>(0,1) = -sin(new_prev_to_cur_transform[k].da);
T.at<double>(1,0) = sin(new_prev_to_cur_transform[k].da);
T.at<double>(1,1) = cos(new_prev_to_cur_transform[k].da);
T.at<double>(0,2) = new_prev_to_cur_transform[k].dx;
T.at<double>(1,2) = new_prev_to_cur_transform[k].dy;
Mat cur2;
warpAffine(cur, cur2, T, cur.size());
cur2 = cur2(Range(vert_border, cur2.rows-vert_border), Range(HORIZONTAL_BORDER_CROP, cur2.cols-HORIZONTAL_BORDER_CROP));
// Resize cur2 back to cur size, for better side by side comparison
resize(cur2, cur2, cur.size());
// Now draw the original and stablised side by side for coolness
Mat canvas = Mat::zeros(cur.rows, cur.cols*2+10, cur.type());
cur.copyTo(canvas(Range::all(), Range(0, cur2.cols)));
cur2.copyTo(canvas(Range::all(), Range(cur2.cols+10, cur2.cols*2+10)));
// If too big to fit on the screen, then scale it down by 2, hopefully it'll fit :)
if(canvas.cols > 1920) {
resize(canvas, canvas, Size(canvas.cols/2, canvas.rows/2));
}
imshow("before and after", canvas);
//char str[256];
//sprintf(str, "images/%08d.jpg", k);
//imwrite(str, canvas);
waitKey(20);
k++;
}
return 0;
}