(Very) small fix for FilterConvolveMatrix::area_enlarge

diff --git a/src/display/nr-filter-convolve-matrix.cpp b/src/display/nr-filter-convolve-matrix.cpp
index 0fd46202e49e5be8e2172cfcc6e9c8aeec4c24ad..e9f7e7dfe14436fc82e5f9d2128a7fe1e02e9d6f 100644 (file)
--- a/src/display/nr-filter-convolve-matrix.cpp
+++ b/src/display/nr-filter-convolve-matrix.cpp
@@ -252,8 +252,8 @@ void FilterConvolveMatrix::area_enlarge(NRRectL &area, Geom::Matrix const &/*tra
     // some spurious pixels may still appear at the borders when low zooming or rotating. Needs a better fix.
     area.x0 -= targetX;
     area.y0 -= targetY;
-    area.x1 += orderX - targetX;
-    area.y1 += orderY - targetY;
+    area.x1 += orderX - targetX - 1; // This makes sure the last row/column in the original image corresponds to the last row/column in the new image that can be convolved without adjusting the boundary conditions).
+    area.y1 += orderY - targetY - 1;
 }
 
 FilterTraits FilterConvolveMatrix::get_input_traits() {