Add exiv2 to extract ISO, white level, black level

CMakeLists.txt

@@ -33,6 +33,11 @@ find_library(LIBRAW_LIBRARY NAMES raw raw_r)
 include_directories( BEFORE "/usr/local/include/")
 message(STATUS "Found LIBRAW_LIBRARY to be ${LIBRAW_LIBRARY}" )
 
+# Exiv2
+find_package(exiv2 REQUIRED CONFIG NAMES exiv2)
+link_libraries(exiv2lib)
+message(STATUS "Found Exiv2 and linked")
+
 if(NOT APPLE)
   # The clang compiler (on osx) is somehow much more strict
   # than the compilers on ubuntu and so this does not seem

include/hdrplus/merge.h

@@ -17,12 +17,15 @@ class merge
          * @brief Run alignment on burst of images
          * 
          * @param burst_images collection of burst images
-         * @param aligements alignment in pixel value pair. 
+         * @param alignments alignment in pixel value pair. 
          *      Outer most vector is per alternative image.
-         *      Inner most two vector is for horizontle & verticle tiles 
+         *      Inner most two vector is for horizontal & vertical tiles 
          */
         void process( const hdrplus::burst& burst_images, \
-                      std::vector<std::vector<std::vector<std::pair<int, int>>>>& aligements );
+                      std::vector<std::vector<std::vector<std::pair<int, int>>>>& alignments, \
+                      int ISO, \
+                      int white_level, \
+                      double black_level );
 };
 
 } // namespace hdrplus

src/hdrplus_pipeline.cpp

@@ -3,6 +3,7 @@
 #include <vector>
 #include <utility> // std::pair
 #include <opencv2/opencv.hpp> // all opencv header
+#include <exiv2/exiv2.hpp> // exiv2
 #include "hdrplus/hdrplus_pipeline.h"
 #include "hdrplus/burst.h"
 #include "hdrplus/align.h"
@@ -20,11 +21,25 @@ void hdrplus_pipeline::run_pipeline( \
     burst burst_images( burst_path, reference_image_path );
     std::vector<std::vector<std::vector<std::pair<int, int>>>> alignments;
     
+    // Read exif tags
+    Exiv2::Image::AutoPtr image = Exiv2::ImageFactory::open(reference_image_path);
+    assert(image.get() != 0);
+    image->readMetadata();
+    Exiv2::ExifData &exifData = image->exifData();
+    if (exifData.empty()) {
+        std::string error(reference_image_path);
+        error += ": No Exif data found in the file";
+        std::cout << error << std::endl;
+    }
+    int ISO = exifData["Exif.Image.ISOSpeedRatings"].toLong();
+    int white_level = exifData["Exif.Image.WhiteLevel"].toLong();
+    double black_level = exifData["Exif.Image.BlackLevel"].toFloat();
+
     // Run align
     align_module.process( burst_images, alignments );
 
     // Run merging
-    merge_module.process( burst_images, alignments );
+    merge_module.process( burst_images, alignments, ISO, white_level, black_level );
 
     // Run finishing
 }

src/merge.cpp

@@ -7,7 +7,10 @@ namespace hdrplus
 {
 
 void merge::process( const hdrplus::burst& burst_images, \
-                     std::vector<std::vector<std::vector<std::pair<int, int>>>>& aligements )
+                     std::vector<std::vector<std::vector<std::pair<int, int>>>>& alignments, \
+                     int ISO, \
+                     int white_level, \
+                     double black_level )
 {
     
 }