#include <iostream>
static void help(char** argv)
{
cout << "\nThis is a demo program shows how perspective transformation applied on an image, \n"
cout << "\nUsage:\n" << argv[0] << " [image_name -- Default data/right.jpg]\n" << endl;
cout << "\nHot keys: \n"
"\tESC, q - quit the program\n"
"\tr - change order of points to rotate transformation\n"
"\tc - delete selected points\n"
"\ti - change order of points to inverse transformation \n"
"\nUse your mouse to select a point and move it to see transformation changes" << endl;
}
static void onMouse(int event, int x, int y, int, void*);
Mat warping(
Mat image,
Size warped_image_size, vector< Point2f> srcPoints, vector< Point2f> dstPoints);
String windowTitle =
"Perspective Transformation Demo";
String labels[4] = {
"TL",
"TR",
"BR",
"BL" };
vector< Point2f> roi_corners;
vector< Point2f> dst_corners(4);
int roiIndex = 0;
bool dragging;
int selected_corner_index = 0;
bool validation_needed = true;
int main(int argc, char** argv)
{
help(argv);
float original_image_cols = (float)original_image.
cols;
float original_image_rows = (
float)original_image.
rows;
roi_corners.push_back(
Point2f( (
float)(original_image_cols / 1.70), (
float)(original_image_rows / 4.20) ));
roi_corners.push_back(
Point2f( (
float)(original_image.
cols / 1.15), (
float)(original_image.
rows / 3.32) ));
roi_corners.push_back(
Point2f( (
float)(original_image.
cols / 1.33), (
float)(original_image.
rows / 1.10) ));
roi_corners.push_back(
Point2f( (
float)(original_image.
cols / 1.93), (
float)(original_image.
rows / 1.36) ));
bool endProgram = false;
while (!endProgram)
{
if ( validation_needed & (roi_corners.size() < 4) )
{
validation_needed = false;
image = original_image.
clone();
for (size_t i = 0; i < roi_corners.size(); ++i)
{
if( i > 0 )
{
line(image, roi_corners[i-1], roi_corners[(i)],
Scalar(0, 0, 255), 2);
}
}
}
if ( validation_needed & ( roi_corners.size() == 4 ))
{
image = original_image.
clone();
for ( int i = 0; i < 4; ++i )
{
line(image, roi_corners[i], roi_corners[(i + 1) % 4],
Scalar(0, 0, 255), 2);
}
dst_corners[0].x = 0;
dst_corners[0].y = 0;
dst_corners[1].x = (float)
std::max(
norm(roi_corners[0] - roi_corners[1]),
norm(roi_corners[2] - roi_corners[3]));
dst_corners[1].y = 0;
dst_corners[2].x = (float)
std::max(
norm(roi_corners[0] - roi_corners[1]),
norm(roi_corners[2] - roi_corners[3]));
dst_corners[2].y = (float)
std::max(
norm(roi_corners[1] - roi_corners[2]),
norm(roi_corners[3] - roi_corners[0]));
dst_corners[3].x = 0;
dst_corners[3].y = (float)
std::max(
norm(roi_corners[1] - roi_corners[2]),
norm(roi_corners[3] - roi_corners[0]));
imshow(
"Warped Image", warped_image);
}
if ((c == 'q') | (c == 'Q') | (c == 27))
{
endProgram = true;
}
if ((c == 'c') | (c == 'C'))
{
roi_corners.clear();
}
if ((c == 'r') | (c == 'R'))
{
roi_corners.push_back(roi_corners[0]);
roi_corners.erase(roi_corners.begin());
}
if ((c == 'i') | (c == 'I'))
{
swap(roi_corners[0], roi_corners[1]);
swap(roi_corners[2], roi_corners[3]);
}
}
return 0;
}
static void onMouse(int event, int x, int y, int, void*)
{
if (roi_corners.size() == 4)
{
for (int i = 0; i < 4; ++i)
{
{
selected_corner_index = i;
dragging = true;
}
}
}
{
roi_corners.push_back(
Point2f( (
float) x, (
float) y ) );
validation_needed = true;
}
{
dragging = false;
}
{
roi_corners[selected_corner_index].x = (float) x;
roi_corners[selected_corner_index].y = (float) y;
validation_needed = true;
}
}