Added translation parameter into stitching module warpers. For now only…

Added translation parameter into stitching module warpers. For now only PlaneWarper and PlaneWarperGpu warpers support it.

modules/stitching/include/opencv2/stitching/detail/warpers.hpp

@@ -57,20 +57,26 @@ class CV_EXPORTS Warper
 public:
     virtual ~Warper() {}
     virtual Point warp(const Mat &src, const Mat &K, const Mat &R, Mat &dst,
-                       int interp_mode = INTER_LINEAR, int border_mode = BORDER_REFLECT) = 0;
+                       int interp_mode, int border_mode) = 0;
+    virtual Point warp(const Mat &src, const Mat &K, const Mat &R, const Mat &T, Mat &dst,
+                       int interp_mode, int border_mode) = 0;
     virtual Rect warpRoi(const Size &sz, const Mat &K, const Mat &R) = 0;
+    virtual Rect warpRoi(const Size &sz, const Mat &K, const Mat &R, const Mat &T) = 0;
 };
 
 
 struct CV_EXPORTS ProjectorBase
 {
-    void setCameraParams(const Mat &K, const Mat &R);
+    void setCameraParams(const Mat &K = Mat::eye(3, 3, CV_32F), 
+                         const Mat &R = Mat::eye(3, 3, CV_32F), 
+                         const Mat &T = Mat::zeros(3, 1, CV_32F));
 
     float scale;
     float k[9];
     float rinv[9];
     float r_kinv[9];
     float k_rinv[9];
+    float t[3];
 };
 
 
@@ -78,10 +84,12 @@ template <class P>
 class CV_EXPORTS WarperBase : public Warper
 {   
 public:
-    virtual Point warp(const Mat &src, const Mat &K, const Mat &R, Mat &dst,
+    Point warp(const Mat &src, const Mat &K, const Mat &R, Mat &dst,
                int interp_mode, int border_mode);
-
-    virtual Rect warpRoi(const Size &sz, const Mat &K, const Mat &R);
+    Point warp(const Mat &src, const Mat &K, const Mat &R, const Mat &T, Mat &dst,
+               int interp_mode, int border_mode);
+    Rect warpRoi(const Size &sz, const Mat &K, const Mat &R);
+    Rect warpRoi(const Size &sz, const Mat &K, const Mat &R, const Mat &T);
 
 protected:
     // Detects ROI of the destination image. It's correct for any projection.
@@ -108,6 +116,10 @@ class CV_EXPORTS PlaneWarper : public WarperBase<PlaneProjector>
 {
 public:
     PlaneWarper(float scale = 1.f) { projector_.scale = scale; }
+    void setScale(float scale) { projector_.scale = scale; }
+    Point warp(const Mat &src, const Mat &K, const Mat &R, const Mat &T, Mat &dst,
+               int interp_mode, int border_mode);
+    Rect warpRoi(const Size &sz, const Mat &K, const Mat &R, const Mat &T);
 
 protected:
     void detectResultRoi(Point &dst_tl, Point &dst_br);
@@ -120,6 +132,8 @@ public:
     PlaneWarperGpu(float scale = 1.f) : PlaneWarper(scale) {}
     Point warp(const Mat &src, const Mat &K, const Mat &R, Mat &dst,
                int interp_mode, int border_mode);
+    Point warp(const Mat &src, const Mat &K, const Mat &R, const Mat &T, Mat &dst,
+               int interp_mode, int border_mode);
 
 private:
     gpu::GpuMat d_xmap_, d_ymap_, d_dst_, d_src_;

modules/stitching/include/opencv2/stitching/detail/warpers_inl.hpp

@@ -80,6 +80,15 @@ Point WarperBase<P>::warp(const Mat &src, const Mat &K, const Mat &R, Mat &dst,
 }
 
 
+template <class P>
+Point WarperBase<P>::warp(const Mat &/*src*/, const Mat &/*K*/, const Mat &/*R*/, const Mat &/*T*/, Mat &/*dst*/,
+                          int /*interp_mode*/, int /*border_mode*/)
+{
+    CV_Error(CV_StsNotImplemented, "translation support isn't implemented");
+    return Point();
+}
+
+
 template <class P>
 Rect WarperBase<P>::warpRoi(const Size &sz, const Mat &K, const Mat &R)
 {
@@ -93,6 +102,14 @@ Rect WarperBase<P>::warpRoi(const Size &sz, const Mat &K, const Mat &R)
 }
 
 
+template <class P>
+Rect WarperBase<P>::warpRoi(const Size &sz, const Mat &K, const Mat &R, const Mat &T)
+{
+    CV_Error(CV_StsNotImplemented, "translation support isn't implemented");
+    return Rect();
+}
+
+
 template <class P>
 void WarperBase<P>::detectResultRoi(Point &dst_tl, Point &dst_br)
 {
@@ -163,21 +180,24 @@ void PlaneProjector::mapForward(float x, float y, float &u, float &v)
     float y_ = r_kinv[3] * x + r_kinv[4] * y + r_kinv[5];
     float z_ = r_kinv[6] * x + r_kinv[7] * y + r_kinv[8];
 
-    u = scale * x_ / z_;
-    v = scale * y_ / z_;
+    x_ = t[0] + x_ / z_ * (1 - t[2]);
+    y_ = t[1] + y_ / z_ * (1 - t[2]);
+
+    u = scale * x_;
+    v = scale * y_;
 }
 
 
 inline
 void PlaneProjector::mapBackward(float u, float v, float &x, float &y)
 {
-    u /= scale;
-    v /= scale;
+    u = u / scale - t[0];
+    v = v / scale - t[1];
 
     float z;
-    x = k_rinv[0] * u + k_rinv[1] * v + k_rinv[2];
-    y = k_rinv[3] * u + k_rinv[4] * v + k_rinv[5];
-    z = k_rinv[6] * u + k_rinv[7] * v + k_rinv[8];
+    x = k_rinv[0] * u + k_rinv[1] * v + k_rinv[2] * (1 - t[2]);
+    y = k_rinv[3] * u + k_rinv[4] * v + k_rinv[5] * (1 - t[2]);
+    z = k_rinv[6] * u + k_rinv[7] * v + k_rinv[8] * (1 - t[2]);
 
     x /= z;
     y /= z;

modules/stitching/src/stitcher.cpp

@@ -237,7 +237,7 @@ Stitcher::Status Stitcher::stitch(InputArray imgs_, OutputArray pano_)
         K(0,0) *= seam_work_aspect; K(0,2) *= seam_work_aspect;
         K(1,1) *= seam_work_aspect; K(1,2) *= seam_work_aspect;
 
-        corners[i] = warper->warp(seam_est_imgs[i], K, cameras[i].R, images_warped[i]);
+        corners[i] = warper->warp(seam_est_imgs[i], K, cameras[i].R, images_warped[i], INTER_LINEAR, BORDER_REFLECT);
         sizes[i] = images_warped[i].size();
 
         warper->warp(masks[i], K, cameras[i].R, masks_warped[i], INTER_NEAREST, BORDER_CONSTANT);
@@ -321,7 +321,7 @@ Stitcher::Status Stitcher::stitch(InputArray imgs_, OutputArray pano_)
         cameras[img_idx].K().convertTo(K, CV_32F);
 
         // Warp the current image
-        warper->warp(img, K, cameras[img_idx].R, img_warped);
+        warper->warp(img, K, cameras[img_idx].R, img_warped, INTER_LINEAR, BORDER_REFLECT);
 
         // Warp the current image mask
         mask.create(img_size, CV_8U);

modules/stitching/src/warpers.cpp

@@ -47,10 +47,11 @@ using namespace std;
 namespace cv {
 namespace detail {
 
-void ProjectorBase::setCameraParams(const Mat &K, const Mat &R)
+void ProjectorBase::setCameraParams(const Mat &K, const Mat &R, const Mat &T)
 {
     CV_Assert(K.size() == Size(3, 3) && K.type() == CV_32F);
     CV_Assert(R.size() == Size(3, 3) && R.type() == CV_32F);
+    CV_Assert((T.size() == Size(1, 3) || T.size() == Size(3, 1)) && T.type() == CV_32F);
 
     Mat_<float> K_(K);
     k[0] = K_(0,0); k[1] = K_(0,1); k[2] = K_(0,2);
@@ -71,6 +72,51 @@ void ProjectorBase::setCameraParams(const Mat &K, const Mat &R)
     k_rinv[0] = K_Rinv(0,0); k_rinv[1] = K_Rinv(0,1); k_rinv[2] = K_Rinv(0,2); 
     k_rinv[3] = K_Rinv(1,0); k_rinv[4] = K_Rinv(1,1); k_rinv[5] = K_Rinv(1,2); 
     k_rinv[6] = K_Rinv(2,0); k_rinv[7] = K_Rinv(2,1); k_rinv[8] = K_Rinv(2,2); 
+
+    Mat_<float> T_(T.reshape(0, 3));
+    t[0] = T_(0,0); t[1] = T_(1,0); t[2] = T_(2,0);
+}
+
+
+Point PlaneWarper::warp(const Mat &src, const Mat &K, const Mat &R, const Mat &T, Mat &dst,
+                        int interp_mode, int border_mode)
+{
+    src_size_ = src.size();
+    projector_.setCameraParams(K, R, T);
+
+    Point dst_tl, dst_br;
+    detectResultRoi(dst_tl, dst_br);
+
+    Mat xmap(dst_br.y - dst_tl.y + 1, dst_br.x - dst_tl.x + 1, CV_32F);
+    Mat ymap(dst_br.y - dst_tl.y + 1, dst_br.x - dst_tl.x + 1, CV_32F);
+
+    float x, y;
+    for (int v = dst_tl.y; v <= dst_br.y; ++v)
+    {
+        for (int u = dst_tl.x; u <= dst_br.x; ++u)
+        {
+            projector_.mapBackward(static_cast<float>(u), static_cast<float>(v), x, y);
+            xmap.at<float>(v - dst_tl.y, u - dst_tl.x) = x;
+            ymap.at<float>(v - dst_tl.y, u - dst_tl.x) = y;
+        }
+    }
+
+    dst.create(dst_br.y - dst_tl.y + 1, dst_br.x - dst_tl.x + 1, src.type());
+    remap(src, dst, xmap, ymap, interp_mode, border_mode);
+
+    return dst_tl;
+}
+
+
+Rect PlaneWarper::warpRoi(const Size &sz, const Mat &K, const Mat &R, const Mat &T)
+{
+    src_size_ = sz;
+    projector_.setCameraParams(K, R, T);
+
+    Point dst_tl, dst_br;
+    detectResultRoi(dst_tl, dst_br);
+
+    return Rect(dst_tl, Point(dst_br.x + 1, dst_br.y + 1));
 }
 
 
@@ -105,11 +151,20 @@ void PlaneWarper::detectResultRoi(Point &dst_tl, Point &dst_br)
     dst_br.y = static_cast<int>(br_vf);
 }
 
+
 #ifndef ANDROID
-Point PlaneWarperGpu::warp(const Mat &src, const Mat &K, const Mat &R, Mat &dst, int interp_mode, int border_mode)
+Point PlaneWarperGpu::warp(const Mat &src, const Mat &K, const Mat &R, Mat &dst, 
+                           int interp_mode, int border_mode)
+{
+    return warp(src, K, R, Mat::zeros(3, 1, CV_32F), dst, interp_mode, border_mode);
+}
+
+
+Point PlaneWarperGpu::warp(const Mat &src, const Mat &K, const Mat &R, const Mat &T, Mat &dst, 
+                           int interp_mode, int border_mode)
 {
     src_size_ = src.size();
-    projector_.setCameraParams(K, R);
+    projector_.setCameraParams(K, R, T);
 
     Point dst_tl, dst_br;
     detectResultRoi(dst_tl, dst_br);
@@ -145,8 +200,6 @@ void SphericalWarper::detectResultRoi(Point &dst_tl, Point &dst_br)
     float z = projector_.rinv[7];
     if (y > 0.f)
     {
-        //x = projector_.focal * x / z + src_size_.width * 0.5f;
-        //y = projector_.focal * y / z + src_size_.height * 0.5f;
         float x_ = (projector_.k[0] * x + projector_.k[1] * y) / z + projector_.k[2];
         float y_ = projector_.k[4] * y / z + projector_.k[5];
         if (x_ > 0.f && x_ < src_size_.width && y_ > 0.f && y_ < src_size_.height)
@@ -161,8 +214,6 @@ void SphericalWarper::detectResultRoi(Point &dst_tl, Point &dst_br)
     z = projector_.rinv[7];
     if (y > 0.f)
     {
-        //x = projector_.focal * x / z + src_size_.width * 0.5f;
-        //y = projector_.focal * y / z + src_size_.height * 0.5f;
         float x_ = (projector_.k[0] * x + projector_.k[1] * y) / z + projector_.k[2];
         float y_ = projector_.k[4] * y / z + projector_.k[5];
         if (x_ > 0.f && x_ < src_size_.width && y_ > 0.f && y_ < src_size_.height)
@@ -178,6 +229,7 @@ void SphericalWarper::detectResultRoi(Point &dst_tl, Point &dst_br)
     dst_br.y = static_cast<int>(br_vf);
 }
 
+
 #ifndef ANDROID
 Point SphericalWarperGpu::warp(const Mat &src, const Mat &K, const Mat &R, Mat &dst,
                                int interp_mode, int border_mode)

samples/cpp/stitching_detailed.cpp

@@ -485,7 +485,7 @@ int main(int argc, char* argv[])
         K(0,0) *= seam_work_aspect; K(0,2) *= seam_work_aspect;
         K(1,1) *= seam_work_aspect; K(1,2) *= seam_work_aspect;
 
-        corners[i] = warper->warp(images[i], K, cameras[i].R, images_warped[i]);
+        corners[i] = warper->warp(images[i], K, cameras[i].R, images_warped[i], INTER_LINEAR, BORDER_REFLECT);
         sizes[i] = images_warped[i].size();
 
         warper->warp(masks[i], K, cameras[i].R, masks_warped[i], INTER_NEAREST, BORDER_CONSTANT);
@@ -572,7 +572,7 @@ int main(int argc, char* argv[])
         cameras[img_idx].K().convertTo(K, CV_32F);
 
         // Warp the current image
-        warper->warp(img, K, cameras[img_idx].R, img_warped);
+        warper->warp(img, K, cameras[img_idx].R, img_warped, INTER_LINEAR, BORDER_REFLECT);
 
         // Warp the current image mask
         mask.create(img_size, CV_8U);