diff --git a/modules/v4d/include/opencv2/v4d/detail/framebuffercontext.hpp b/modules/v4d/include/opencv2/v4d/detail/framebuffercontext.hpp
index 2e3afe45e..ede333480 100644
--- a/modules/v4d/include/opencv2/v4d/detail/framebuffercontext.hpp
+++ b/modules/v4d/include/opencv2/v4d/detail/framebuffercontext.hpp
@@ -209,15 +209,15 @@ public:
     bool isClosed();
     bool isShared();
     void fence();
-    bool wait(uint64_t timeout = 0);
+    bool wait(const uint64_t& timeout = 0);
     /*!
      * Blit the framebuffer to the screen
      * @param viewport ROI to blit
      * @param windowSize The size of the window to blit to
      * @param stretch if true stretch the framebuffer to window size
      */
-    void blitFrameBufferToFrameBuffer(const cv::Rect& viewport, const cv::Size& windowSize,
-            bool stretch = false, GLuint drawFramebufferID = 0, bool flipY = false);
+    void blitFrameBufferToFrameBuffer(const cv::Rect& srcViewport, const cv::Size& targetFbSize,
+            GLuint targetFramebufferID = 0, bool stretch = true, bool flipY = false);
 protected:
     cv::Ptr<V4D> getV4D();
     int getIndex();
diff --git a/modules/v4d/src/detail/framebuffercontext.cpp b/modules/v4d/src/detail/framebuffercontext.cpp
index c21b1912e..a898001fd 100644
--- a/modules/v4d/src/detail/framebuffercontext.cpp
+++ b/modules/v4d/src/detail/framebuffercontext.cpp
@@ -144,7 +144,7 @@ void FrameBufferContext::doWebGLCopy(FrameBufferContext& other) {
         other.blitFrameBufferToFrameBuffer(
                 cv::Rect(0,0, other.size().width, other.size().height),
                 this->getWindowSize(),
-                false);
+                0, false);
         emscripten_webgl_commit_frame();
     }
     this->makeCurrent();
@@ -379,7 +379,7 @@ void FrameBufferContext::init() {
             V4D* v4d = reinterpret_cast<V4D*>(glfwGetWindowUserPointer(glfwWin));
             if(v4d->getGLFWWindow() == glfwWin) {
                 v4d->setFocused(i == 1);
-                cerr << "FOCUSED: " << v4d->title() << endl;
+//                cerr << "FOCUSED: " << v4d->title() << endl;
             }
     });
 }
@@ -645,11 +645,11 @@ CLExecContext_t& FrameBufferContext::getCLExecContext() {
 }
 #endif
 
-void FrameBufferContext::blitFrameBufferToFrameBuffer(const cv::Rect& viewport,
-        const cv::Size& windowSize, bool stretch, GLuint drawFramebufferID, bool flipY) {
+void FrameBufferContext::blitFrameBufferToFrameBuffer(const cv::Rect& srcViewport,
+        const cv::Size& targetFbSize, GLuint targetFramebufferID, bool stretch, bool flipY) {
     this->makeCurrent();
-    double hf = double(windowSize.height) / framebufferSize_.height;
-    double wf = double(windowSize.width) / framebufferSize_.width;
+    double hf = double(targetFbSize.height) / framebufferSize_.height;
+    double wf = double(targetFbSize.width) / framebufferSize_.width;
     double f;
     if (hf > wf)
         f = wf;
@@ -659,15 +659,15 @@ void FrameBufferContext::blitFrameBufferToFrameBuffer(const cv::Rect& viewport,
     double fbws = framebufferSize_.width * f;
     double fbhs = framebufferSize_.height * f;
 
-    double marginw = (windowSize.width - framebufferSize_.width) / 2.0;
-    double marginh = (windowSize.height - framebufferSize_.height) / 2.0;
-    double marginws = (windowSize.width - fbws) / 2.0;
-    double marginhs = (windowSize.height - fbhs) / 2.0;
+    double marginw = (targetFbSize.width - framebufferSize_.width) / 2.0;
+    double marginh = (targetFbSize.height - framebufferSize_.height) / 2.0;
+    double marginws = (targetFbSize.width - fbws) / 2.0;
+    double marginhs = (targetFbSize.height - fbhs) / 2.0;
 
-    GLint srcX0 = viewport.x;
-    GLint srcY0 = viewport.y;
-    GLint srcX1 = viewport.x + viewport.width;
-    GLint srcY1 = viewport.y + viewport.height;
+    GLint srcX0 = srcViewport.x;
+    GLint srcY0 = srcViewport.y;
+    GLint srcX1 = srcViewport.x + srcViewport.width;
+    GLint srcY1 = srcViewport.y + srcViewport.height;
     GLint dstX0 = stretch ? marginws : marginw;
     GLint dstY0 = stretch ? marginhs : marginh;
     GLint dstX1 = stretch ? marginws + fbws : marginw + framebufferSize_.width;
@@ -678,7 +678,7 @@ void FrameBufferContext::blitFrameBufferToFrameBuffer(const cv::Rect& viewport,
         dstY1 = tmp;
 
     }
-    GL_CHECK(glBindFramebuffer(GL_DRAW_FRAMEBUFFER, drawFramebufferID));
+    GL_CHECK(glBindFramebuffer(GL_DRAW_FRAMEBUFFER, targetFramebufferID));
     GL_CHECK(glBlitFramebuffer( srcX0, srcY0, srcX1, srcY1,
             dstX0, dstY0, dstX1, dstY1,
             GL_COLOR_BUFFER_BIT, GL_NEAREST));
@@ -875,7 +875,7 @@ void FrameBufferContext::fence() {
     CV_Assert(current_sync_object_ != 0);
 }
 
-bool FrameBufferContext::wait(uint64_t timeout) {
+bool FrameBufferContext::wait(const uint64_t& timeout) {
     if(first_sync_) {
         current_sync_object_ = 0;
         first_sync_ = false;
diff --git a/modules/v4d/src/util.cpp b/modules/v4d/src/util.cpp
index 7b1c9710a..4a5585edf 100644
--- a/modules/v4d/src/util.cpp
+++ b/modules/v4d/src/util.cpp
@@ -469,7 +469,7 @@ public:
             );
             GL_CHECK(glFramebufferTexture2D(GL_READ_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0));
             cv::Size fbSz = window_->framebufferSize();
-            window_->fbCtx().blitFrameBufferToFrameBuffer(cv::Rect(0, 0, width_, height_), cv::Size(width_, height_), false, window_->fbCtx().getFramebufferID(), true);
+            window_->fbCtx().blitFrameBufferToFrameBuffer(cv::Rect(0, 0, width_, height_), cv::Size(width_, height_), window_->fbCtx().getFramebufferID(), true, true);
 
             return true;
         }
diff --git a/modules/v4d/src/v4d.cpp b/modules/v4d/src/v4d.cpp
index 742a5726a..b9346cc8c 100644
--- a/modules/v4d/src/v4d.cpp
+++ b/modules/v4d/src/v4d.cpp
@@ -505,7 +505,7 @@ void V4D::swapContextBuffers() {
     run_sync_on_main<10>([this]() {
         for(size_t i = 0; i < numGlCtx(); ++i) {
             FrameBufferContext::GLScope glScope(glCtx(i).fbCtx(), GL_READ_FRAMEBUFFER);
-            glCtx(i).fbCtx().blitFrameBufferToFrameBuffer(viewport(), glCtx(i).fbCtx().getWindowSize(), isStretching());
+            glCtx(i).fbCtx().blitFrameBufferToFrameBuffer(viewport(), glCtx(i).fbCtx().getWindowSize(), 0, isStretching());
 #ifndef __EMSCRIPTEN__
             glfwSwapBuffers(glCtx(i).fbCtx().getGLFWWindow());
 #else
@@ -516,7 +516,7 @@ void V4D::swapContextBuffers() {
 
     run_sync_on_main<11>([this]() {
         FrameBufferContext::GLScope glScope(nvgCtx().fbCtx(), GL_READ_FRAMEBUFFER);
-        nvgCtx().fbCtx().blitFrameBufferToFrameBuffer(viewport(), nvgCtx().fbCtx().getWindowSize(), isStretching());
+        nvgCtx().fbCtx().blitFrameBufferToFrameBuffer(viewport(), nvgCtx().fbCtx().getWindowSize(), 0, isStretching());
 #ifndef __EMSCRIPTEN__
         glfwSwapBuffers(nvgCtx().fbCtx().getGLFWWindow());
 #else
@@ -535,7 +535,7 @@ bool V4D::display() {
         run_sync_on_main<6>([&, this]() {
             {
                 FrameBufferContext::GLScope glScope(fbCtx(), GL_READ_FRAMEBUFFER);
-                fbCtx().blitFrameBufferToFrameBuffer(viewport(), fbCtx().getWindowSize(), isStretching());
+                fbCtx().blitFrameBufferToFrameBuffer(viewport(), fbCtx().getWindowSize(), 0, isStretching());
             }
             imguiCtx().render(getShowFPS());
 #ifndef __EMSCRIPTEN__