DNG: use black/white levels and matrix from the file, unless it comes from the Adobe DNG Converter

See #4472

rtengine/dcraw.cc

@@ -6113,6 +6113,7 @@ int CLASS parse_tiff_ifd (int base)
 	break;
       case 305:  case 11:		/* Software */
 	fgets (software, 64, ifp);
+        RT_software = software;
 	if (!strncmp(software,"Adobe",5) ||
 	    !strncmp(software,"dcraw",5) ||
 	    !strncmp(software,"UFRaw",5) ||
@@ -6395,15 +6396,18 @@ guess_cfa_pc:
 			  cblack[6+c] = getreal(type);
 		}
 		black = 0;
+                RT_blacklevel_from_constant = ThreeValBool::F;
 		break;
       case 50715:			/* BlackLevelDeltaH */
       case 50716:			/* BlackLevelDeltaV */
 	for (num=i=0; i < (len & 0xffff); i++)
 	  num += getreal(type);
 	black += num/len + 0.5;
+        RT_blacklevel_from_constant = ThreeValBool::F;
 	break;
       case 50717:			/* WhiteLevel */
 	maximum = getint(type);
+        RT_whitelevel_from_constant = ThreeValBool::F;
 	break;
       case 50718:			/* DefaultScale */
 	pixel_aspect  = getreal(type);
@@ -6541,8 +6545,6 @@ guess_cfa_pc:
   if (!use_cm)
     FORCC pre_mul[c] /= cc[cm_D65][c][c];
 
-  RT_from_adobe_dng_converter = !strncmp(software, "Adobe DNG Converter", 19);
-
   return 0;
 }
 
@@ -10042,7 +10044,8 @@ bw:   colors = 1;
 dng_skip:
   if ((use_camera_matrix & (use_camera_wb || dng_version))
         && cmatrix[0][0] > 0.125
-        && !RT_from_adobe_dng_converter /* RT -- do not use the embedded
+        && strncmp(RT_software.c_str(), "Adobe DNG Converter", 19) != 0
+      /* RT -- do not use the embedded
        * matrices for DNGs coming from the
        * Adobe DNG Converter, to ensure
        * consistency of WB values between

rtengine/dcraw.h

@@ -55,10 +55,9 @@ public:
     ,verbose(0)
     ,use_auto_wb(0),use_camera_wb(0),use_camera_matrix(1)
     ,output_color(1),output_bps(8),output_tiff(0),med_passes(0),no_auto_bright(0)
-    ,RT_whitelevel_from_constant(0)
+    ,RT_whitelevel_from_constant(ThreeValBool::X)
-    ,RT_blacklevel_from_constant(0)
+    ,RT_blacklevel_from_constant(ThreeValBool::X)
-    ,RT_matrix_from_constant(0)
+    ,RT_matrix_from_constant(ThreeValBool::X)
-    ,RT_from_adobe_dng_converter(false)
 	,getbithuff(this,ifp,zero_after_ff)
 	,nikbithuff(ifp)
     {
@@ -150,10 +149,11 @@ protected:
     int output_color, output_bps, output_tiff, med_passes;
     int no_auto_bright;
     unsigned greybox[4] ;
-    int RT_whitelevel_from_constant;
+    enum class ThreeValBool { X = -1, F, T };
-    int RT_blacklevel_from_constant;
+    ThreeValBool RT_whitelevel_from_constant;
-    int RT_matrix_from_constant;
+    ThreeValBool RT_blacklevel_from_constant;
-    bool RT_from_adobe_dng_converter;
+    ThreeValBool RT_matrix_from_constant;
+    std::string RT_software;
 
     float cam_mul[4], pre_mul[4], cmatrix[3][4], rgb_cam[3][4];
 

rtengine/rawimage.cc

@@ -30,9 +30,9 @@ RawImage::RawImage(  const Glib::ustring &name )
     , allocation(nullptr)
 {
     memset(maximum_c4, 0, sizeof(maximum_c4));
-    RT_matrix_from_constant = 0;
+    RT_matrix_from_constant = ThreeValBool::X;
-    RT_blacklevel_from_constant = 0;
+    RT_blacklevel_from_constant = ThreeValBool::X;
-    RT_whitelevel_from_constant = 0;
+    RT_whitelevel_from_constant = ThreeValBool::X;
 }
 
 RawImage::~RawImage()
@@ -599,14 +599,14 @@ int RawImage::loadRaw (bool loadData, unsigned int imageNum, bool closeFile, Pro
 
         if (cc) {
             for (int i = 0; i < 4; i++) {
-                if (RT_blacklevel_from_constant) {
+                if (RT_blacklevel_from_constant == ThreeValBool::T) {
                     int blackFromCc = cc->get_BlackLevel(i, iso_speed);
                     // if black level from camconst > 0xffff it is an absolute value.
                     black_c4[i] = blackFromCc > 0xffff ? (blackFromCc & 0xffff) : blackFromCc + cblack[i];
                 }
 
                 // load 4 channel white level here, will be used if available
-                if (RT_whitelevel_from_constant) {
+                if (RT_whitelevel_from_constant == ThreeValBool::T) {
                     maximum_c4[i] = cc->get_WhiteLevel(i, iso_speed, aperture);
 
                     if(tiff_bps > 0 && maximum_c4[i] > 0 && !isFoveon()) {
@@ -1049,6 +1049,15 @@ DCraw::dcraw_coeff_overrides(const char make[], const char model[], const int is
 
     *black_level = -1;
     *white_level = -1;
+
+    const bool is_pentax_dng = dng_version && !strncmp(RT_software.c_str(), "PENTAX", 6);
+    
+    if (RT_blacklevel_from_constant == ThreeValBool::F && !is_pentax_dng) {
+        *black_level = black;
+    }
+    if (RT_whitelevel_from_constant == ThreeValBool::F && !is_pentax_dng) {
+        *white_level = maximum;
+    }
     memset(trans, 0, sizeof(*trans) * 12);
 
     // indicate that DCRAW wants these from constants (rather than having loaded these from RAW file
@@ -1056,9 +1065,15 @@ DCraw::dcraw_coeff_overrides(const char make[], const char model[], const int is
     // from file, but then we will not provide any black level in the tables. This case is mainly just
     // to avoid loading table values if we have loaded a DNG conversion of a raw file (which already
     // have constants stored in the file).
-    RT_whitelevel_from_constant = 1;
+    if (RT_whitelevel_from_constant == ThreeValBool::X || is_pentax_dng) {
-    RT_blacklevel_from_constant = 1;
+        RT_whitelevel_from_constant = ThreeValBool::T;
-    RT_matrix_from_constant = 1;
+    }
+    if (RT_blacklevel_from_constant == ThreeValBool::X || is_pentax_dng) {
+        RT_blacklevel_from_constant = ThreeValBool::T;
+    }
+    if (RT_matrix_from_constant == ThreeValBool::X) {
+        RT_matrix_from_constant = ThreeValBool::T;
+    }
 
     {
         // test if we have any information in the camera constants store, if so we take that.
@@ -1066,8 +1081,12 @@ DCraw::dcraw_coeff_overrides(const char make[], const char model[], const int is
         rtengine::CameraConst *cc = ccs->get(make, model);
 
         if (cc) {
+            if (RT_blacklevel_from_constant == ThreeValBool::T) {
                 *black_level = cc->get_BlackLevel(0, iso_speed);
+            }
+            if (RT_whitelevel_from_constant == ThreeValBool::T) {
                 *white_level = cc->get_WhiteLevel(0, iso_speed, aperture);
+            }
 
             if (cc->has_dcrawMatrix()) {
                 const short *mx = cc->get_dcrawMatrix();
@@ -1086,8 +1105,12 @@ DCraw::dcraw_coeff_overrides(const char make[], const char model[], const int is
 
     for (size_t i = 0; i < sizeof table / sizeof(table[0]); i++) {
         if (strcasecmp(name, table[i].prefix) == 0) {
+            if (RT_blacklevel_from_constant == ThreeValBool::T) {
                 *black_level = table[i].black_level;
+            }
+            if (RT_whitelevel_from_constant == ThreeValBool::T) {
                 *white_level = table[i].white_level;
+            }
 
             for (int j = 0; j < 12; j++) {
                 trans[j] = table[i].trans[j];