Upgraded load_image_dataset() so that it returns the list of ignored

rectangles.

dlib/data_io/load_image_dataset.h

@@ -24,7 +24,7 @@ namespace dlib
         typename image_type, 
         typename MM
         >
-    void load_image_dataset (
+    std::vector<std::vector<rectangle> > load_image_dataset (
         array<image_type,MM>& images,
         std::vector<std::vector<rectangle> >& object_locations,
         const std::string& filename,
@@ -36,6 +36,8 @@ namespace dlib
         object_locations.clear();
         const std::string old_working_dir = get_current_dir();
 
+        std::vector<std::vector<rectangle> > ignored_rects;
+
         // Set the current directory to be the one that contains the
         // metadata file. We do this because the file might contain
         // file paths which are relative to this folder.
@@ -49,27 +51,33 @@ namespace dlib
         load_image_dataset_metadata(data, filename);
 
         image_type img;
-        std::vector<rectangle> rects;
+        std::vector<rectangle> rects, ignored;
         for (unsigned long i = 0; i < data.images.size(); ++i)
         {
             rects.clear();
+            ignored.clear();
             for (unsigned long j = 0; j < data.images[i].boxes.size(); ++j)
             {
                 if (label.size() == 0 || data.images[i].boxes[j].label == label)
                 {
-                    rects.push_back(data.images[i].boxes[j].rect);
+                    if (data.images[i].boxes[j].ignore)
+                        ignored.push_back(data.images[i].boxes[j].rect);
+                    else
+                        rects.push_back(data.images[i].boxes[j].rect);
                 }
             }
 
             if (!skip_empty_images || rects.size() != 0)
             {
                 object_locations.push_back(rects);
+                ignored_rects.push_back(ignored);
                 load_image(img, data.images[i].filename);
                 images.push_back(img);
             }
         }
 
         set_current_dir(old_working_dir);
+        return ignored_rects;
     }
 
 // ----------------------------------------------------------------------------------------
@@ -78,13 +86,13 @@ namespace dlib
         typename image_type, 
         typename MM
         >
-    void load_image_dataset (
+    std::vector<std::vector<rectangle> > load_image_dataset (
         array<image_type,MM>& images,
         std::vector<std::vector<rectangle> >& object_locations,
         const std::string& filename
     )
     {
-        load_image_dataset(images, object_locations, filename, "");
+        return load_image_dataset(images, object_locations, filename, "");
     }
 
 // ----------------------------------------------------------------------------------------

dlib/data_io/load_image_dataset_abstract.h

@@ -19,7 +19,7 @@ namespace dlib
         typename image_type, 
         typename MM
         >
-    void load_image_dataset (
+    std::vector<std::vector<rectangle> > load_image_dataset (
         array<image_type,MM>& images,
         std::vector<std::vector<rectangle> >& object_locations,
         const std::string& filename,
@@ -39,17 +39,25 @@ namespace dlib
             - #images.size() == #object_locations.size()
             - This routine is capable of loading any image format which can be read by the
               load_image() routine.
+            - let IGNORED_RECTS denote the vector returned from this function.
+            - IGNORED_RECTS.size() == #object_locations.size()
+            - IGNORED_RECTS == a list of the rectangles which have the "ignore" flag set to
+              true in the XML file.
             - for all valid i:  
-                - #images[i] == a copy of the i-th image from the dataset
+                - #images[i] == a copy of the i-th image from the dataset.
                 - #object_locations[i] == a vector of all the rectangles associated with
-                  #images[i].  
+                  #images[i].  Note that only rectangles that are not marked as "ignore"
+                  are stored into #object_locations.
+                - IGNORED_RECTS[i] == A vector of all the rectangles associated with
+                  #images[i] that are marked as "ignore".
                 - if (skip_empty_images == true) then
                     - #object_locations[i].size() != 0
-                      (i.e. only images with detection boxes in them will be loaded.)
+                      (i.e. only images with non-ignored boxes in them will be loaded.)
                 - if (labels != "") then
-                    - only boxes with the given label will be loaded into object_locations.
+                    - Only boxes with the given label will be loaded into object_locations
+                      and IGNORED_RECTS.
                 - else
-                    - all boxes in the dataset will be loaded into object_locations.
+                    - all boxes in the dataset will be loaded regardless of their labels.
     !*/
 
 // ----------------------------------------------------------------------------------------
@@ -58,7 +66,7 @@ namespace dlib
         typename image_type, 
         typename MM
         >
-    void load_image_dataset (
+    std::vector<std::vector<rectangle> > load_image_dataset (
         array<image_type,MM>& images,
         std::vector<std::vector<rectangle> >& object_locations,
         const std::string& filename
@@ -68,7 +76,7 @@ namespace dlib
             - image_type == is an implementation of array2d/array2d_kernel_abstract.h
             - pixel_traits<typename image_type::type> is defined  
         ensures
-            - performs: load_image_dataset(images, object_locations, filename, "");
+            - performs: return load_image_dataset(images, object_locations, filename, "");
               (i.e. it ignores box labels and therefore loads all the boxes in the dataset)
     !*/