diff --git a/rtengine/dfmanager.cc b/rtengine/dfmanager.cc
index ab76ff854..1dedf661f 100644
--- a/rtengine/dfmanager.cc
+++ b/rtengine/dfmanager.cc
@@ -138,7 +138,8 @@ void dfInfo::updateRawImage()
         std::list<Glib::ustring>::iterator iName = pathNames.begin();
         ri = new RawImage(*iName); // First file used also for extra pixels informations (width,height, shutter, filters etc.. )
 
-        if( ri->loadRaw(true)) {
+        unsigned int imageNum = 0;
+        if( ri->loadRaw(true, imageNum)) {
             delete ri;
             ri = nullptr;
         } else {
@@ -163,7 +164,7 @@ void dfInfo::updateRawImage()
             for( ++iName; iName != pathNames.end(); ++iName) {
                 RawImage* temp = new RawImage(*iName);
 
-                if( !temp->loadRaw(true)) {
+                if( !temp->loadRaw(true,imageNum)) {
                     temp->compress_image();     //\ TODO would be better working on original, because is temporary
                     nFiles++;
 
@@ -199,8 +200,9 @@ void dfInfo::updateRawImage()
         }
     } else {
         ri = new RawImage(pathname);
+        unsigned int imageNum = 0;
 
-        if( ri->loadRaw(true)) {
+        if( ri->loadRaw(true,imageNum)) {
             delete ri;
             ri = nullptr;
         } else {
@@ -365,7 +367,8 @@ dfInfo* DFManager::addFileInfo (const Glib::ustring& filename, bool pool)
         }
 
         RawImage ri (filename);
-        int res = ri.loadRaw (false); // Read informations about shot
+        unsigned int imageNum = 0;
+        int res = ri.loadRaw (false, imageNum); // Read informations about shot
 
         if (res != 0) {
             return nullptr;
diff --git a/rtengine/ffmanager.cc b/rtengine/ffmanager.cc
index 069bbf563..42a46802b 100644
--- a/rtengine/ffmanager.cc
+++ b/rtengine/ffmanager.cc
@@ -130,8 +130,8 @@ void ffInfo::updateRawImage()
     if( !pathNames.empty() ) {
         std::list<Glib::ustring>::iterator iName = pathNames.begin();
         ri = new RawImage(*iName); // First file used also for extra pixels informations (width,height, shutter, filters etc.. )
-
-        if( ri->loadRaw(true)) {
+        unsigned int imageNum = 0;
+        if( ri->loadRaw(true, imageNum)) {
             delete ri;
             ri = nullptr;
         } else {
@@ -156,7 +156,7 @@ void ffInfo::updateRawImage()
             for( ++iName; iName != pathNames.end(); ++iName) {
                 RawImage* temp = new RawImage(*iName);
 
-                if( !temp->loadRaw(true)) {
+                if( !temp->loadRaw(true,imageNum)) {
                     temp->compress_image();     //\ TODO would be better working on original, because is temporary
                     nFiles++;
 
@@ -192,8 +192,9 @@ void ffInfo::updateRawImage()
         }
     } else {
         ri = new RawImage(pathname);
+        unsigned int imageNum = 0;
 
-        if( ri->loadRaw(true)) {
+        if( ri->loadRaw(true, imageNum)) {
             delete ri;
             ri = nullptr;
         } else {
@@ -326,7 +327,8 @@ ffInfo* FFManager::addFileInfo (const Glib::ustring& filename, bool pool)
 
 
         RawImage ri (filename);
-        int res = ri.loadRaw (false); // Read informations about shot
+        unsigned int imageNum = 0;
+        int res = ri.loadRaw (false, imageNum); // Read informations about shot
 
         if (res != 0) {
             return nullptr;
diff --git a/rtengine/imagesource.h b/rtengine/imagesource.h
index 4acffef6c..98e5446a1 100644
--- a/rtengine/imagesource.h
+++ b/rtengine/imagesource.h
@@ -80,6 +80,9 @@ public:
 
     virtual bool        IsrgbSourceModified() const = 0; // tracks whether cached rgb output of demosaic has been modified
 
+    virtual void setCurrentFrame(unsigned int frameNum) = 0;
+
+
     // use right after demosaicing image, add coarse transformation and put the result in the provided Imagefloat*
     virtual void        getImage    (const ColorTemp &ctemp, int tran, Imagefloat* image, const PreviewProps &pp, const ToneCurveParams &hlp, const ColorManagementParams &cmp, const RAWParams &raw) = 0;
     virtual eSensorType getSensorType ()
diff --git a/rtengine/improccoordinator.cc b/rtengine/improccoordinator.cc
index 741370813..afa791b4f 100644
--- a/rtengine/improccoordinator.cc
+++ b/rtengine/improccoordinator.cc
@@ -185,6 +185,7 @@ void ImProcCoordinator::updatePreviewImage (int todo, Crop* cropCall)
 
     // raw auto CA is bypassed if no high detail is needed, so we have to compute it when high detail is needed
     if ( (todo & M_PREPROC) || (!highDetailPreprocessComputed && highDetailNeeded)) {
+        imgsrc->setCurrentFrame(params.raw.bayersensor.imageNum);
         imgsrc->preprocess( rp, params.lensProf, params.coarse );
         imgsrc->getRAWHistogram( histRedRaw, histGreenRaw, histBlueRaw );
 
diff --git a/rtengine/rawimage.cc b/rtengine/rawimage.cc
index 0ec9f548c..85d6a00b5 100644
--- a/rtengine/rawimage.cc
+++ b/rtengine/rawimage.cc
@@ -398,7 +398,7 @@ skip_block:
     }
 }
 
-int RawImage::loadRaw (bool loadData, unsigned int imageNum, bool closeFile, ProgressListener *plistener, double progressRange)
+int RawImage::loadRaw (bool loadData, unsigned int &imageNum, bool closeFile, ProgressListener *plistener, double progressRange)
 {
     ifname = filename.c_str();
     image = nullptr;
@@ -427,8 +427,10 @@ int RawImage::loadRaw (bool loadData, unsigned int imageNum, bool closeFile, Pro
 
     identify ();
 
+    std::cout << "israw : " << is_raw << std::endl;
     // in case dcraw didn't handle the above mentioned case...
     shot_select = std::min(shot_select, std::max(is_raw, 1u) - 1);
+    imageNum = shot_select;
 
     if (!is_raw) {
         fclose(ifp);
diff --git a/rtengine/rawimage.h b/rtengine/rawimage.h
index 4f39ac855..4080702a6 100644
--- a/rtengine/rawimage.h
+++ b/rtengine/rawimage.h
@@ -106,7 +106,7 @@ public:
     explicit RawImage( const Glib::ustring &name );
     ~RawImage();
 
-    int loadRaw (bool loadData = true, unsigned int imageNum = 0, bool closeFile = true, ProgressListener *plistener = nullptr, double progressRange = 1.0);
+    int loadRaw (bool loadData, unsigned int &imageNum, bool closeFile = true, ProgressListener *plistener = nullptr, double progressRange = 1.0);
     void get_colorsCoeff( float* pre_mul_, float* scale_mul_, float* cblack_, bool forceAutoWB );
     void set_prefilters()
     {
diff --git a/rtengine/rawimagesource.cc b/rtengine/rawimagesource.cc
index 737e733cd..1d30706aa 100644
--- a/rtengine/rawimagesource.cc
+++ b/rtengine/rawimagesource.cc
@@ -475,8 +475,8 @@ RawImageSource::~RawImageSource ()
 
     delete idata;
 
-    if (ri) {
-        delete ri;
+    for(size_t i = 0; i < numFrames; ++i) {
+        delete riFrames[i];
     }
 
     flushRGB();
@@ -1506,14 +1506,29 @@ int RawImageSource::load (const Glib::ustring &fname, int imageNum, bool batch)
         plistener->setProgress (0.0);
     }
 
-    ri = new RawImage(fname);
-    int errCode = ri->loadRaw (true, imageNum, true, plistener, 0.8);
+    unsigned int tempImageNum = 4;
+    do {
+        tempImageNum --;
+        numFrames ++;
+        ri = new RawImage(fname);
+        int errCode = ri->loadRaw (true, tempImageNum, true, plistener, 0.8);
+        std::cout << "imagenum : " << tempImageNum <<  " width : " << ri->get_width() << " height : " << ri->get_height() << std::endl;
 
-    if (errCode) {
-        return errCode;
+        if (errCode) {
+            return errCode;
+        }
+        riFrames[tempImageNum] = ri;
+        ri->compress_image();
+        ri->set_prefilters();
+    } while (tempImageNum);
+
+    if(numFrames > 1 ) {
+        if(riFrames[0]->get_width() != riFrames[1]->get_width() || riFrames[0]->get_height() != riFrames[1]->get_height()) {
+            numFrames = 1;
+        }
     }
 
-    ri->compress_image();
+std::cout << "numframes : " << numFrames << std::endl;
 
     if (plistener) {
         plistener->setProgress (0.9);
@@ -1627,7 +1642,6 @@ int RawImageSource::load (const Glib::ustring &fname, int imageNum, bool batch)
     }*/
 
 
-    ri->set_prefilters();
 
     //Load complete Exif informations
     RawMetaDataLocation rml;
diff --git a/rtengine/rawimagesource.h b/rtengine/rawimagesource.h
index cec3d78b7..79d89be88 100644
--- a/rtengine/rawimagesource.h
+++ b/rtengine/rawimagesource.h
@@ -25,7 +25,7 @@
 #include "curves.h"
 #include "color.h"
 #include "iimage.h"
-
+#include <iostream>
 #define HR_SCALE 2
 
 namespace rtengine
@@ -71,6 +71,9 @@ protected:
     bool rgbSourceModified;
 
     RawImage* ri;  // Copy of raw pixels, NOT corrected for initial gain, blackpoint etc.
+    RawImage* riFrames[16] = {nullptr};
+    unsigned int currFrame = 0;
+    unsigned int numFrames = 0;
 
     // to accelerate CIELAB conversion:
     double lc00, lc01, lc02, lc10, lc11, lc12, lc20, lc21, lc22;
@@ -195,7 +198,11 @@ public:
     static void HLRecovery_blend (float* rin, float* gin, float* bin, int width, float maxval, float* hlmax);
     static void init ();
     static void cleanup ();
-
+    void setCurrentFrame(unsigned int frameNum) {
+        currFrame = std::min(numFrames - 1, frameNum);
+        ri = riFrames[currFrame];
+        std::cout << "currFrame : " << currFrame << std::endl;
+    }
 protected:
     typedef unsigned short ushort;
     void processFalseColorCorrection (Imagefloat* i, const int steps);
diff --git a/rtengine/refreshmap.cc b/rtengine/refreshmap.cc
index 8325ac17d..33e988674 100644
--- a/rtengine/refreshmap.cc
+++ b/rtengine/refreshmap.cc
@@ -470,7 +470,7 @@ int refreshmap[rtengine::NUMOFEVENTS] = {
     RETINEX,          // EvRetinexgaintransmission
     RETINEX,          // EvLskal
     OUTPUTPROFILE,    // EvOBPCompens
-    DEMOSAIC          // EvRawImageNum
+    DARKFRAME          // EvRawImageNum
 
 };
 
diff --git a/rtengine/rtthumbnail.cc b/rtengine/rtthumbnail.cc
index 6321f0dcf..9b71d2156 100644
--- a/rtengine/rtthumbnail.cc
+++ b/rtengine/rtthumbnail.cc
@@ -156,7 +156,8 @@ Thumbnail* Thumbnail::loadFromImage (const Glib::ustring& fname, int &w, int &h,
 Thumbnail* Thumbnail::loadQuickFromRaw (const Glib::ustring& fname, RawMetaDataLocation& rml, int &w, int &h, int fixwh, bool rotate, bool inspectorMode)
 {
     RawImage *ri = new RawImage(fname);
-    int r = ri->loadRaw(false, 0, false);
+    unsigned int imageNum = 0;
+    int r = ri->loadRaw(false, imageNum, false);
 
     if( r ) {
         delete ri;
@@ -270,7 +271,9 @@ RawMetaDataLocation Thumbnail::loadMetaDataFromRaw (const Glib::ustring& fname)
     rml.ciffLength = -1;
 
     RawImage ri(fname);
-    int r = ri.loadRaw(false);
+    unsigned int imageNum = 0;
+
+    int r = ri.loadRaw(false, imageNum);
 
     if( !r ) {
         rml.exifBase = ri.get_exifBase();
@@ -284,7 +287,9 @@ RawMetaDataLocation Thumbnail::loadMetaDataFromRaw (const Glib::ustring& fname)
 Thumbnail* Thumbnail::loadFromRaw (const Glib::ustring& fname, RawMetaDataLocation& rml, int &w, int &h, int fixwh, double wbEq, bool rotate, int imageNum)
 {
     RawImage *ri = new RawImage (fname);
-    int r = ri->loadRaw(1, imageNum, 0);
+    unsigned int tempImageNum = 0;
+
+    int r = ri->loadRaw(1, tempImageNum, 0);
 
     if( r ) {
         delete ri;
diff --git a/rtengine/simpleprocess.cc b/rtengine/simpleprocess.cc
index 9e7d5f58f..250875b6a 100644
--- a/rtengine/simpleprocess.cc
+++ b/rtengine/simpleprocess.cc
@@ -102,6 +102,7 @@ IImage16* processImage (ProcessingJob* pjob, int& errorCode, ProgressListener* p
     ImProcFunctions ipf (&params, true);
 
     PreviewProps pp (0, 0, fw, fh, 1);
+    imgsrc->setCurrentFrame(params.raw.bayersensor.imageNum);
     imgsrc->preprocess( params.raw, params.lensProf, params.coarse, params.dirpyrDenoise.enabled);
 
     if (params.toneCurve.autoexp) {// this enabled HLRecovery
diff --git a/rtengine/stdimagesource.h b/rtengine/stdimagesource.h
index 38b6952b0..733a44c42 100644
--- a/rtengine/stdimagesource.h
+++ b/rtengine/stdimagesource.h
@@ -95,6 +95,8 @@ public:
     {
         return rgbSourceModified;
     }
+    void setCurrentFrame(unsigned int frameNum) {}
+
 };
 }
 #endif