Index: trunk/ppStack/src/ppStackReadout.c
===================================================================
--- trunk/ppStack/src/ppStackReadout.c	(revision 36710)
+++ trunk/ppStack/src/ppStackReadout.c	(revision 36855)
@@ -34,4 +34,5 @@
     bool safety = PS_SCALAR_VALUE(args->data[4], U8);    // Safety switch on?
     bool normalise = PS_SCALAR_VALUE(args->data[5], U8); // Normalise images?
+    bool bscaleoffset = PS_SCALAR_VALUE(args->data[6], U8); // Apply bscale offset?
 
     psVector *mask = options->inputMask; // Mask for inputs
@@ -40,7 +41,8 @@
     psVector *addVariance = options->matchChi2; // Additional variance when rejecting
     psVector *norm = normalise ? options->norm : NULL; // Normalisations to apply to images
+    psVector *bscaleApplyOffset = bscaleoffset ? options->bscaleOffset : NULL; // BSCALE offset to apply to images
 
     bool status = ppStackReadoutFinal(config, options->outRO, options->expRO, thread->readouts, mask, reject,
-                                      weightings, exposures, addVariance, safety, norm); // Status of operation
+                                      weightings, exposures, addVariance, safety, norm, bscaleApplyOffset); // Status of operation
 
     thread->busy = false;
@@ -201,5 +203,5 @@
                          const psVector *mask, const psArray *rejected, const psVector *weightings,
                          const psVector *exposures, const psVector *addVariance, bool safety,
-                         const psVector *norm)
+                         const psVector *norm, const psVector *bscaleApplyOffset)
 {
     assert(config);
@@ -271,4 +273,10 @@
         stack->data[i] = data;
 
+        //MEH -- apply bscale offset before norm   
+        if (bscaleApplyOffset) {
+            psLogMsg("ppStack", PS_LOG_INFO, "bscaleApplyOffset: %d %f", i, bscaleApplyOffset->data.F32[i]);
+            psBinaryOp(ro->image, ro->image, "-", psScalarAlloc(bscaleApplyOffset->data.F32[i], PS_TYPE_F32));
+        }
+
         if (norm) {
             float normalise = powf(10.0, -0.4 * norm->data.F32[i]); // Normalisation