Index: trunk/ppBackground/src/ppBackgroundRestore.c
===================================================================
--- trunk/ppBackground/src/ppBackgroundRestore.c	(revision 34297)
+++ trunk/ppBackground/src/ppBackgroundRestore.c	(revision 34298)
@@ -59,7 +59,15 @@
         psImage *patternImage = patternRO->image; // Image with pattern
         psImage *patternMask = patternRO->mask;   // Mask for pattern
+        // The sign is flipped for the continuity correction.
+        bool mdok;
+        bool isContinuity = psMetadataLookupBool(&mdok, pattern->hdu->header, "PTRN_CON");
+        
         for (int y = 0; y < numRows; y++) {
             for (int x = 0; x < numCols; x++) {
-                image->data.F32[y][x] -= patternImage->data.F32[y][x];
+                if (isContinuity) {
+                    image->data.F32[y][x] += patternImage->data.F32[y][x];
+                } else {
+                    image->data.F32[y][x] -= patternImage->data.F32[y][x];
+                }
                 mask->data.PS_TYPE_IMAGE_MASK_DATA[y][x] |= patternMask->data.PS_TYPE_IMAGE_MASK_DATA[y][x];
             }