diff --git a/rtengine/FTblockDN.cc b/rtengine/FTblockDN.cc
index 8a61f7a6e..f85948cb2 100644
--- a/rtengine/FTblockDN.cc
+++ b/rtengine/FTblockDN.cc
@@ -214,9 +214,6 @@ namespace rtengine {
 				//residual between input and denoised L channel
 				array2D<float> Ldetail(width,height);
 
-#ifdef _OPENMP
-#pragma omp parallel for
-#endif
 				//fill tile from image
 				for (int i=tiletop, i1=0; i<tilebottom; i++, i1++) 
 					for (int j=tileleft, j1=0; j<tileright; j++, j1++) {
@@ -425,9 +422,6 @@ namespace rtengine {
 				}
 
 				
-#ifdef _OPENMP
-#pragma omp parallel for
-#endif
 				for (int i=tiletop, i1=0; i<tilebottom; i++, i1++) {
 					float X,Y,Z;
 					for (int j=tileleft, j1=0; j<tileright; j++, j1++) {
@@ -442,15 +436,11 @@ namespace rtengine {
 						
 						//Y = 65535.0f*(0.05+0.1*((float)rand()/(float)RAND_MAX));//test with random data
 						
-						float mask = Vmask[i1]*Hmask[j1];
+						float factor = Vmask[i1]*Hmask[j1]/gain;
 						
-						if (Y<-500) {
-							float xxx=Y;
-						}
-						
-						dsttmp->r[i][j] += mask*X/gain;//prophoto_xyz[0][0]*X + prophoto_xyz[0][1]*Y + prophoto_xyz[0][2]*Z;
-						dsttmp->g[i][j] += mask*Y/gain;//prophoto_xyz[1][0]*X + prophoto_xyz[1][1]*Y + prophoto_xyz[1][2]*Z;
-						dsttmp->b[i][j] += mask*Z/gain;//prophoto_xyz[2][0]*X + prophoto_xyz[2][1]*Y + prophoto_xyz[2][2]*Z;
+						dsttmp->r[i][j] += factor*X;//prophoto_xyz[0][0]*X + prophoto_xyz[0][1]*Y + prophoto_xyz[0][2]*Z;
+						dsttmp->g[i][j] += factor*Y;//prophoto_xyz[1][0]*X + prophoto_xyz[1][1]*Y + prophoto_xyz[1][2]*Z;
+						dsttmp->b[i][j] += factor*Z;//prophoto_xyz[2][0]*X + prophoto_xyz[2][1]*Y + prophoto_xyz[2][2]*Z;
 						
 					}
 				}
@@ -797,7 +787,7 @@ namespace rtengine {
 						
 						
 					}
-				}
+				}//now chrominance coefficients are denoised
 			}
 			
 			if (noisevar_L>0.01) {
@@ -833,7 +823,7 @@ namespace rtengine {
 					//use smoothed shrinkage unless local shrinkage is much less
 					WavCoeffs_L[dir][i] *= (SQR(sfave[i])+SQR(sf))/(sfave[i]+sf+eps);
 					
-				}//now luminance coeffs are denoised
+				}//now luminance coefficients are denoised
 			}
 			
 			
@@ -847,5 +837,5 @@ namespace rtengine {
 	//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 	
 	
-};
+}
 
diff --git a/rtengine/improccoordinator.cc b/rtengine/improccoordinator.cc
index 4038d2f8a..9c1aa83d0 100644
--- a/rtengine/improccoordinator.cc
+++ b/rtengine/improccoordinator.cc
@@ -159,6 +159,13 @@ void ImProcCoordinator::updatePreviewImage (int todo, Crop* cropCall) {
         params.wb.temperature = currWB.getTemp ();
         params.wb.green = currWB.getGreen ();
     	imgsrc->demosaic( rp );
+		
+		LUTu aehist; int aehistcompr;
+		double clip;
+		int brightness, contrast, black, hlcompr, hlcomprthresh;
+		
+		imgsrc->getAutoExpHistogram (aehist, aehistcompr);
+		ipf.getAutoExp (aehist, aehistcompr, clip, params.dirpyrDenoise.expcomp, brightness, contrast, black, hlcompr, hlcomprthresh);	
     }
     lastHighDetail=highDetailNeeded;
 
@@ -194,13 +201,6 @@ void ImProcCoordinator::updatePreviewImage (int todo, Crop* cropCall) {
         PreviewProps pp (0, 0, fw, fh, scale);
         setScale (scale);
         imgsrc->getImage (currWB, tr, orig_prev, pp, params.hlrecovery, params.icm, params.raw);
-		
-		LUTu aehist; int aehistcompr;
-		double clip;
-		int brightness, contrast, black, hlcompr, hlcomprthresh;
-		
-		imgsrc->getAutoExpHistogram (aehist, aehistcompr);
-		ipf.getAutoExp (aehist, aehistcompr, clip, params.dirpyrDenoise.expcomp, brightness, contrast, black, hlcompr, hlcomprthresh);		
 
         if (todo & M_LINDENOISE) {
         	//printf("denoising!\n");