updated docs

docs/docs/imaging.xml

@@ -125,6 +125,7 @@
          </item>
 
          <item>hog_image</item>
+         <item>extract_fhog_features</item>
          <item>fine_hog_image</item>
          <item>poly_image</item>
          <item>hashed_feature_image</item>
@@ -205,6 +206,7 @@
          <item>toMat</item>
 
          <item>draw_line</item> 
+         <item>draw_fhog</item> 
          <item>fill_rect</item> 
          <item>assign_image</item> 
          <item>assign_image_scaled</item> 
@@ -379,6 +381,26 @@
                                  
       </component>
 
+   <!-- ************************************************************************* -->
+      
+      <component>
+         <name>extract_fhog_features</name>
+         <file>dlib/image_transforms.h</file>
+         <spec_file link="true">dlib/image_transforms/fhog_abstract.h</spec_file>
+         <description>
+              This function implements the HOG feature extraction method described in 
+              the paper:
+                <blockquote>
+                  Object Detection with Discriminatively Trained Part Based Models by
+                  P. Felzenszwalb, R. Girshick, D. McAllester, D. Ramanan
+                  in IEEE Transactions on Pattern Analysis and Machine Intelligence, Vol. 32, No. 9, Sep. 2010
+                </blockquote>
+              This means that it takes an input image and outputs Felzenszwalb's
+              31 dimensional version of HOG features.
+         </description>
+                                 
+      </component>
+
    <!-- ************************************************************************* -->
       
       <component>
@@ -979,6 +1001,23 @@
                                  
       </component>
             
+   <!-- ************************************************************************* -->
+      
+      <component>
+         <name>draw_fhog</name>
+         <file>dlib/image_transforms.h</file>
+         <spec_file link="true">dlib/image_transforms/fhog_abstract.h</spec_file>
+         <description>        
+            This function takes a FHOG feature map which was created by 
+            <a href="#extract_fhog_features">extract_fhog_features</a> and
+              converts it into an image suitable for display on the screen.  In
+              particular, we draw all the hog cells into a grayscale image in a
+              way that shows the magnitude and orientation of the gradient
+              energy in each cell.  
+         </description>
+                                 
+      </component>
+            
    <!-- ************************************************************************* -->
       
       <component>

docs/docs/term_index.xml

@@ -1245,6 +1245,10 @@
          <term file="imaging.html" name="compute_dominant_angle"  include="dlib/image_keypoint.h"/>
          <term file="imaging.html" name="draw_surf_points"        include="dlib/image_keypoint/draw_surf_points.h"/>
          <term file="imaging.html" name="compute_surf_descriptor" include="dlib/image_keypoint.h"/>
+         <term file="imaging.html" name="extract_fhog_features"   include="dlib/image_transforms.h"/>
+         <term file="imaging.html" name="draw_fhog"               include="dlib/image_transforms.h"/>
+         <term file="dlib/image_transforms/fhog_abstract.h.html"  name="fhog_to_image" include="dlib/image_transforms.h"/>
+         <term file="dlib/image_transforms/fhog_abstract.h.html"  name="image_to_fhog" include="dlib/image_transforms.h"/>
          <term file="imaging.html" name="hog_image"               include="dlib/image_keypoint.h"/>
          <term file="imaging.html" name="fine_hog_image"          include="dlib/image_keypoint.h"/>
          <term file="imaging.html" name="poly_image"              include="dlib/image_keypoint.h"/>