Fix typos in comments (#444)

include/boost/gil/concepts/channel.hpp

@@ -66,7 +66,7 @@ auto channel_convert(SrcT const& val)
 ///     static const bool is_mutable;        // use channel_traits<T>::is_mutable to access it
 ///
 ///     static T min_value();                // use channel_traits<T>::min_value to access it
-///     static T max_value();                // use channel_traits<T>::min_value to access it
+///     static T max_value();                // use channel_traits<T>::max_value to access it
 /// };
 /// \endcode
 template <typename T>

include/boost/gil/concepts/image_view.hpp

@@ -39,7 +39,7 @@ namespace boost { namespace gil {
 /// \ingroup ImageViewConcept
 /// \brief N-dimensional range
 
-/// \defgroup ImageView2DConcept ImageView2DConcept
+/// \defgroup ImageView2DConcept ImageView2DLocatorConcept
 /// \ingroup ImageViewConcept
 /// \brief 2-dimensional range
 

include/boost/gil/image_processing/threshold.hpp

@@ -45,7 +45,7 @@ void threshold_impl(SrcView const& src_view, DstView const& dst_view, Operator c
         typename color_space_type<DstView>::type
     >::value, "Source and destination views must have pixels with the same color space");
 
-    //iterate over the image chaecking each pixel value for the threshold
+    //iterate over the image checking each pixel value for the threshold
     for (std::ptrdiff_t y = 0; y < src_view.height(); y++)
     {
         typename SrcView::x_iterator src_it = src_view.row_begin(y);
@@ -64,7 +64,7 @@ void threshold_impl(SrcView const& src_view, DstView const& dst_view, Operator c
 /// @{
 ///
 /// \brief Direction of image segmentation.
-/// The direction specifieds which pixels are considered as corresponding to object
+/// The direction specifies which pixels are considered as corresponding to object
 /// and which pixels correspond to background.
 enum class threshold_direction
 {
@@ -160,13 +160,13 @@ void threshold_binary(
 
 /// \ingroup ImageProcessing
 /// \brief Applies truncating threshold to each pixel of image view.
-/// Takes an image view and performes truncating threshold operation on each chennel.
+/// Takes an image view and performs truncating threshold operation on each chennel.
 /// If mode is threshold and direction is regular:
 /// values greater than threshold_value will be set to threshold_value else no change
 /// If mode is threshold and direction is inverse:
-/// values less than threshold_value will be set to threshold_value else no change
+/// values less than or equal to threshold_value will be set to threshold_value else no change
 /// If mode is zero and direction is regular:
-/// values less than threshold_value will be set to 0 else no change
+/// values less than or equal to threshold_value will be set to 0 else no change
 /// If mode is zero and direction is inverse:
 /// values more than threshold_value will be set to 0 else no change
 template <typename SrcView, typename DstView>
@@ -372,7 +372,7 @@ void adaptive_impl
         typename color_space_type<DstView>::type
     >::value, "Source and destination views must have pixels with the same color space");
 
-    //iterate over the image chaecking each pixel value for the threshold
+    //iterate over the image checking each pixel value for the threshold
     for (std::ptrdiff_t y = 0; y < src_view.height(); y++)
     {
         typename SrcView::x_iterator src_it = src_view.row_begin(y);