diff --git a/src/Fl_Gl_Device_Plugin.cxx b/src/Fl_Gl_Device_Plugin.cxx
index 1ab104cae..269a9ef02 100644
--- a/src/Fl_Gl_Device_Plugin.cxx
+++ b/src/Fl_Gl_Device_Plugin.cxx
@@ -57,7 +57,6 @@ uchar *convert_BGRA_to_RGB(uchar *baseAddress, int w, int h, int mByteWidth)
 
 static Fl_RGB_Image* capture_gl_rectangle(Fl_Gl_Window *glw, int x, int y, int w, int h)
 /* captures a rectangle of a Fl_Gl_Window window, and returns it as a RGB image
- stored from bottom to top.
  */
 {
 #if defined(__APPLE__) // PORTME: Fl_Surface_Driver - platform OpenGL management
@@ -93,6 +92,18 @@ static Fl_RGB_Image* capture_gl_rectangle(Fl_Gl_Window *glw, int x, int y, int w
   baseAddress = convert_BGRA_to_RGB(baseAddress, w, h, mByteWidth);
   mByteWidth = 3 * w;
 #endif
+  
+  // GL gives a bottom-to-top image, convert it to top-to-bottom
+  uchar *tmp = new uchar[mByteWidth];
+  uchar *p = baseAddress ;
+  uchar *q = baseAddress + (h-1)*mByteWidth;
+  for (int i = 0; i < h/2; i++, p += mByteWidth, q -= mByteWidth) {
+    memcpy(tmp, p, mByteWidth);
+    memcpy(p, q, mByteWidth);
+    memcpy(q, tmp, mByteWidth);
+  }
+  delete[] tmp;
+  
   Fl_RGB_Image *img = new Fl_RGB_Image(baseAddress, w, h, 3, mByteWidth);
   img->alloc_array = 1;
   return img;
@@ -110,17 +121,6 @@ public:
     Fl_Gl_Window *glw = w->as_gl_window();
     if (!glw) return 0;
     Fl_RGB_Image *img = capture_gl_rectangle(glw, 0, 0, glw->w(), glw->h());
-    // turn img upside-down
-    int ld = img->ld() ? img->ld() : img->w() * img->d();
-    uchar *tmp = new uchar[ld];
-    uchar *p = (uchar*)img->array ;
-    uchar *q = (uchar*)img->array + (img->h()-1)*ld;
-    for (int i = 0; i < img->h()/2; i++, p += ld, q -= ld) {
-      memcpy(tmp, p, ld);
-      memcpy(p, q, ld);
-      memcpy(q, tmp, ld);
-    }
-    delete[] tmp;
     Fl_Shared_Image *shared = Fl_Shared_Image::get(img);
     shared->scale(glw->w(), glw->h());
     shared->draw(x, y);
diff --git a/src/Fl_cocoa.mm b/src/Fl_cocoa.mm
index 42e85fd69..bbd26c389 100644
--- a/src/Fl_cocoa.mm
+++ b/src/Fl_cocoa.mm
@@ -4091,7 +4091,7 @@ static NSBitmapImageRep* GL_rect_to_nsbitmap(Fl_Window *win, int x, int y, int w
   NSBitmapImageRep* bitmap = [[NSBitmapImageRep alloc] initWithBitmapDataPlanes:NULL pixelsWide:img->w() pixelsHigh:img->h() bitsPerSample:8 samplesPerPixel:4 hasAlpha:YES isPlanar:NO colorSpaceName:NSDeviceRGBColorSpace bytesPerRow:4*img->w() bitsPerPixel:32];
   memset([bitmap bitmapData], 0xFF, [bitmap bytesPerPlane]);
   const uchar *from = img->array;
-  for (int r = img->h() - 1; r >= 0; r--) {
+  for (int r = 0; r < img->h(); r++) {
     uchar *to = [bitmap bitmapData] + r * [bitmap bytesPerRow];
     for (int c = 0; c < img->w(); c++) {
       memcpy(to, from, 3);
diff --git a/src/fl_read_image.cxx b/src/fl_read_image.cxx
index 3a4d8ede3..ebf43c324 100644
--- a/src/fl_read_image.cxx
+++ b/src/fl_read_image.cxx
@@ -45,14 +45,14 @@ static uchar *read_win_rectangle(uchar *p, int X, int Y, int w, int h, int alpha
 
 static void write_image_inside(Fl_RGB_Image *to, Fl_RGB_Image *from, int to_x, int to_y)
 /* Copy the image "from" inside image "to" with its top-left angle at coordinates to_x, to_y.
- Also, exchange top and bottom of "from". Image depth can differ between "to" and "from".
+ Image depth can differ between "to" and "from".
  */
 {
   int to_ld = (to->ld() == 0? to->w() * to->d() : to->ld());
   int from_ld = (from->ld() == 0? from->w() * from->d() : from->ld());
   uchar *tobytes = (uchar*)to->array + to_y * to_ld + to_x * to->d();
-  const uchar *frombytes = from->array + (from->h() - 1) * from_ld;
-  for (int i = from->h() - 1; i >= 0; i--) {
+  const uchar *frombytes = from->array;
+  for (int i = 0; i < from->h(); i++) {
     if (from->d() == to->d()) memcpy(tobytes, frombytes, from->w() * from->d());
     else {
       for (int j = 0; j < from->w(); j++) {
@@ -60,7 +60,7 @@ static void write_image_inside(Fl_RGB_Image *to, Fl_RGB_Image *from, int to_x, i
       }
     }
     tobytes += to_ld;
-    frombytes -= from_ld;
+    frombytes += from_ld;
   }
 }
 
@@ -92,9 +92,9 @@ static Fl_RGB_Image *traverse_to_gl_subwindows(Fl_Group *g, uchar *p, int x, int
     Fl_Plugin_Manager pm("fltk:device");
     Fl_Device_Plugin *pi = (Fl_Device_Plugin*)pm.plugin("opengl.device.fltk.org");
     if (!pi) return full_img;
-    Fl_RGB_Image *img = pi->rectangle_capture(g, x, y, w, h); // bottom to top image
-    if (full_img) full_img = img; // top and bottom will be exchanged later
-    else { // exchange top and bottom to get a proper FLTK image
+    Fl_RGB_Image *img = pi->rectangle_capture(g, x, y, w, h);
+    if (full_img) full_img = img;
+    else {
       uchar *data = ( p ? p : new uchar[img->w() * img->h() * (alpha?4:3)] );
       full_img = new Fl_RGB_Image(data, img->w(), img->h(), alpha?4:3);
       if (!p) full_img->alloc_array = 1;