diff --git a/develop/doc/html/_sources/histogram/create.rst.txt b/develop/doc/html/_sources/histogram/create.rst.txt
new file mode 100644
index 000000000..7df551c63
--- /dev/null
+++ b/develop/doc/html/_sources/histogram/create.rst.txt
@@ -0,0 +1,42 @@
+.. _create_histogram:
+
+Create a histogram
+==================
+
+**Method 1** - Using the histogram constructor
+
+Syntax::
+
+ histogram
+
+``Type1`` .. ``TypeN`` correspond to the axis type of the N axes in the histogram
+
+Example: If we want a 3D histogram of Axis1 of type ``int``, Axis2 of type ``float`` and Axis3 of type ``std::string``
+we would do it this way::
+
+ histogram h;
+
+And done.
+
+
+**Method 2** (TODO) - Using make_histogram()
+
+There is an alternative to create the histogram directly from
+a GIL image view.
+
+This should be the preferred over method-1 when creating
+histogram with GIL images, since it creates a histogram with axes configured
+to match the GIL image.
+
+Also it is easier than method-1.
+
+Syntax::
+
+ auto h = make_histogram(view(image));
+
+where ``image`` could be a ``gray8_image_t``/``rgb8_image_t`` object read from source.
+
+
+
+
+
diff --git a/develop/doc/html/_sources/histogram/cumulative.rst.txt b/develop/doc/html/_sources/histogram/cumulative.rst.txt
new file mode 100644
index 000000000..a769f9ddd
--- /dev/null
+++ b/develop/doc/html/_sources/histogram/cumulative.rst.txt
@@ -0,0 +1,29 @@
+.. _cumulative_histogram:
+
+Making a cumulative histogram
+=============================
+
+Overview
+--------
+
+A cumulative histogram is a histogram in which each bin stores the count / frequency of itself
+as well as all the bins with keys 'smaller' than the particular bin.
+As such, a notion of ordering among its keys should be existant in the histogram.
+
+The GIL histogram class has the ability to convert itself into its cumulative version.
+
+Since the container needs to first get an ordering
+over the keys a key sorting takes place before calculating the cumulative histogram.
+
+Example:
+
+ .. code-block:: cpp
+
+ histogram h;
+ /*
+ Fill histogram ...
+ */
+ auto h1 = cumulative_histogram(h);
+
+Tip: *In case you need to store the cumulative histogram elsewhere, consider creating a copy of the histogram
+and then call the function*.
\ No newline at end of file
diff --git a/develop/doc/html/_sources/histogram/extend.rst.txt b/develop/doc/html/_sources/histogram/extend.rst.txt
new file mode 100644
index 000000000..3197af784
--- /dev/null
+++ b/develop/doc/html/_sources/histogram/extend.rst.txt
@@ -0,0 +1,68 @@
+.. _extend_support:
+
+Extending the class
+===================
+
+.. contents::
+ :local:
+ :depth: 1
+
+User defined Axes
+-----------------
+
+In case you need a histogram with an axes of an arbitrary type that is not identified by
+the C++ Standard Library, you need to provide a overload for the hashing function that is
+used in the histogram class.
+
+GIL's histogram class uses ``boost::hash_combine`` in a sub routine to generate a hash from
+the key.
+
+So we need to provide an overload of ``boost::hash_combine`` for the purpose.
+
+For example, let's consider you need a histogram with an axis over class Test.
+
+.. code-block:: cpp
+
+ // File : ./test.hpp
+ #include
+ #include
+
+ struct Test
+ {
+ int a{0};
+ Test() = default;
+ Test(int c) : a(c) {}
+ bool operator==(Test const& other) const
+ {
+ return (a == other.a);
+ }
+ };
+
+ namespace boost {
+ std::size_t hash_value(Test const& t)
+ {
+ // Replace with your hashing code
+ std::hash hasher;
+ return hasher(t.a);
+ }
+ }
+
+Now lets get to the usage example.
+
+.. code-block:: cpp
+
+ #include
+ #include
+ #include
+ // Mind the order of include i.e. test.hpp before boost/gil.hpp
+
+ using namespace boost::gil;
+
+ int main()
+ {
+ boost::gil::histogram h;
+ Test t(1);
+ h(t) = 1;
+ std::cout< v;
+ gil::gray8_image_t img;
+ /*
+ Fill image ...
+ */
+ gil::fill_histogram(view(img), v, false);
+
+#. **cumulative_histogram()**
+
+ .. code-block:: cpp
+
+ // Demo for std::vector
+ std::vector v;
+ /*
+ Fill vector...
+ */
+ gil::cumulative_histogram(v);
+
+
+
+
+
+
diff --git a/develop/doc/html/_sources/histogram/fill.rst.txt b/develop/doc/html/_sources/histogram/fill.rst.txt
new file mode 100644
index 000000000..cf3f913c6
--- /dev/null
+++ b/develop/doc/html/_sources/histogram/fill.rst.txt
@@ -0,0 +1,103 @@
+.. _fill_it:
+
+Fill histogram
+==============
+
+.. contents::
+ :local:
+ :depth: 1
+
+Overview
+--------
+
+We will demonstrate the available options for filling an instance of the `histogram` class with
+values that cater from the most simplest to the complex needs that might arise.
+
+Basic
+-----
+
+#. Use operator()
+
+ **Task** - Add value to a particular cell / key / bin in histogram
+
+ .. code-block:: cpp
+
+ histogram h;
+ h(1, 2) = 1;
+
+#. Use operator[]
+
+ This requires to input the indices in a format the histogram internally stores its keys,
+ which is of ``std::tuple`` due to its simple interface.
+
+ **Task** - Output value of a bin
+
+ .. code-block:: cpp
+
+ histogram h;
+ h(1, 2) = 1;
+ h[{1, 2}] += 1; // Note the curly braces reqd. to construct a tuple
+ std::cout< A;
+ /*
+ Fill value in A
+ */
+ histogram B(A), C;
+ C = A;
+
+#. Use a GIL image view
+
+ You can also use GIL images to directly fill histograms.
+
+ **Task** - Fill histogram using GIL image view
+
+ .. code-block:: cpp
+
+ gil::gray8_image_t img;
+ /*
+ Fill img ...
+ */
+ histogram h;
+ h.fill(view(img));
+ // OR
+ gil::fill_histogram(view(img), h, false); // false if histogram needs to be cleared before filling
+
+
+Advanced
+--------
+
+#. Fill histogram using only a few dimensions of image
+
+ **Task** - Make an histogram over Red and Blue channel of an rgb image
+
+ .. code-block:: cpp
+
+ gil::rgb8_image_t img;
+ /*
+ Fill img ...
+ */
+ histogram h;
+ fill_histogram<0, 2>(view(img), h, false); // 0 - red, 1 - green, 2 - blue
+
+#. Fill histogram using GIL pixel
+
+ **Task** - Fill histogram bin using pixel construct in GIL
+
+ .. code-block:: cpp
+
+ gil::gray8_image_t img;
+ /*
+ Fill img ...
+ */
+ histogram h;
+ gil::for_each_pixel(view(img), [](gil::gray8_pixel_t const& p){
+ ++h[h.key_from_pixel(p)];
+ });
+
diff --git a/develop/doc/html/_sources/histogram/index.rst.txt b/develop/doc/html/_sources/histogram/index.rst.txt
new file mode 100644
index 000000000..ff8cc16bb
--- /dev/null
+++ b/develop/doc/html/_sources/histogram/index.rst.txt
@@ -0,0 +1,20 @@
+Histogram
+=========
+
+The GIL documentation sections listed below are dedicated to describe the
+histogram class and functions used in many image processing algorithms.
+
+.. toctree::
+ :maxdepth: 1
+ :caption: Table of Contents
+
+ overview
+ create
+ fill
+ subhistogram
+ cumulative
+ stl_compatibility
+ utilities
+ extend
+ limitations
+ extension/index
diff --git a/develop/doc/html/_sources/histogram/limitations.rst.txt b/develop/doc/html/_sources/histogram/limitations.rst.txt
new file mode 100644
index 000000000..819d308f6
--- /dev/null
+++ b/develop/doc/html/_sources/histogram/limitations.rst.txt
@@ -0,0 +1,6 @@
+.. _limitations:
+
+Limitations
+===========
+
+*TODO*
\ No newline at end of file
diff --git a/develop/doc/html/_sources/histogram/overview.rst.txt b/develop/doc/html/_sources/histogram/overview.rst.txt
new file mode 100644
index 000000000..8b222659e
--- /dev/null
+++ b/develop/doc/html/_sources/histogram/overview.rst.txt
@@ -0,0 +1,28 @@
+Overview
+========
+
+.. contents::
+ :local:
+ :depth: 1
+
+Description
+-----------
+
+The histogram class is built on top of std::unordered_map to keep it compatible with other
+STL algorithms. It can support any number of axes (known at compile time i.e. during class
+instantiation). Suitable conversion routines from GIL image constructs to the histogram bin
+key are shipped with the class itself.
+
+
+Tutorials
+---------
+The following flow is recommended:
+ #. :ref:`create_histogram`
+ #. :ref:`fill_it`
+ #. :ref:`sub_histogram`
+ #. :ref:`cumulative_histogram`
+ #. :ref:`stl_compatibility`
+ #. :ref:`extend_support`
+ #. :ref:`limitations`
+
+.. note:: To try out these tutorials you need to get a clone of the repository, since it is not yet released.
diff --git a/develop/doc/html/_sources/histogram/stl_compatibility.rst.txt b/develop/doc/html/_sources/histogram/stl_compatibility.rst.txt
new file mode 100644
index 000000000..9b932a2ce
--- /dev/null
+++ b/develop/doc/html/_sources/histogram/stl_compatibility.rst.txt
@@ -0,0 +1,6 @@
+.. _stl_compatibility:
+
+STL compatibility
+=================
+
+*TODO*
\ No newline at end of file
diff --git a/develop/doc/html/_sources/histogram/subhistogram.rst.txt b/develop/doc/html/_sources/histogram/subhistogram.rst.txt
new file mode 100644
index 000000000..4e046a45a
--- /dev/null
+++ b/develop/doc/html/_sources/histogram/subhistogram.rst.txt
@@ -0,0 +1,66 @@
+.. _sub_histogram:
+
+Making a sub-histogram
+======================
+
+Overview
+--------
+
+Sub-histogram is a subset of a histogram or one that is formed by masking out a
+few axis of the parent histogram.
+
+GIL class histogram provides these functions as members and returns an instance of
+the desired sub-class.
+
+#. Histogram over fewer axes
+
+ **Task** - Get a 2D histogram from a 3D RGB histogram over red and green axes
+
+ .. code-block:: cpp
+
+ histogram h;
+ gil::rgb8_image_t img;
+ /*
+ Fill img ...
+ */
+ fill_histogram(view(img), h, false);
+ auto sub_h = h.sub_histogram<0, 1>(); // sub_h is a 2D histogram
+
+ Demo output:
+
+ .. code-block:: cpp
+
+ h is {{1, 2, 3} : 1,
+ {1, 4, 3} : 2,
+ {1, 2, 5} : 3}
+ sub_h would be {{1, 2} : 4, {1, 4} : 2}
+
+#. Histogram using a particular key range
+
+ **Task** - Get a 2D histogram from a 3D RGB histogram for bins whose red color lie between 10 - 20
+ and blue color lie between 2 - 10
+
+ .. code-block:: cpp
+
+ histogram h;
+ gil::rgb8_image_t img;
+ /*
+ Fill img ...
+ */
+ fill_histogram(view(img), h, false);
+ std::tuple low, high;
+ low = {10, 0, 2} // Since no check over blue channel pass any dummy value
+ high = {20, 0, 10} // Since no check over blue channel pass any dummy value
+ auto sub_h = h.sub_histogram<0, 2>(low, high); // In angle brackets pass the relevant dimensions in order
+
+ Demo Output:
+
+ .. code-block:: cpp
+
+ h is {{11, 2, 3 } : 1,
+ {1 , 4, 11} : 2,
+ {1 , 2, 1 } : 3,
+ {11, 3, 3 } : 4}
+ sub_h would be {{11, 2, 3} : 1, {11, 3, 3} : 4}
+
+
diff --git a/develop/doc/html/_sources/histogram/utilities.rst.txt b/develop/doc/html/_sources/histogram/utilities.rst.txt
new file mode 100644
index 000000000..5c4bf7755
--- /dev/null
+++ b/develop/doc/html/_sources/histogram/utilities.rst.txt
@@ -0,0 +1,6 @@
+.. _utilities:
+
+Utilities
+=========
+
+*TODO*
\ No newline at end of file
diff --git a/develop/doc/html/_sources/image_processing/contrast_enhancement/index.rst.txt b/develop/doc/html/_sources/image_processing/contrast_enhancement/index.rst.txt
new file mode 100644
index 000000000..60c60cd46
--- /dev/null
+++ b/develop/doc/html/_sources/image_processing/contrast_enhancement/index.rst.txt
@@ -0,0 +1,11 @@
+Contrast Enhancement
+====================
+
+The GIL documentation sections listed below are dedicated to describe image
+processing algorithms used for contrast enhancement.
+
+.. toctree::
+ :maxdepth: 1
+ :caption: Table of Contents
+
+ overview
\ No newline at end of file
diff --git a/develop/doc/html/_sources/image_processing/contrast_enhancement/overview.rst.txt b/develop/doc/html/_sources/image_processing/contrast_enhancement/overview.rst.txt
new file mode 100644
index 000000000..467705511
--- /dev/null
+++ b/develop/doc/html/_sources/image_processing/contrast_enhancement/overview.rst.txt
@@ -0,0 +1,15 @@
+Overview
+========
+
+Contrast Enhancement is a significant part of image processing algorithms. Too dark or too
+light images don't look good to the human eyes. Hence while the primary focus of these
+algorithms is to enhance visual beauty, some applications of this in medical research is also
+prevalent.
+
+We have a few contrast enhancement algorithms in the GIL image processing suite as well.
+These include :
+ #. :ref:`he`
+ #. :ref:`hm`
+ #. :ref:`ahe`
+ #. Linear and Non-Linear Contrast stretching
+
diff --git a/develop/doc/html/_sources/image_processing/index.rst.txt b/develop/doc/html/_sources/image_processing/index.rst.txt
index 71c01c742..c5bc61cfa 100644
--- a/develop/doc/html/_sources/image_processing/index.rst.txt
+++ b/develop/doc/html/_sources/image_processing/index.rst.txt
@@ -11,3 +11,5 @@ features, structures and algorithms, for image processing and analysis.
overview
basics
affine-region-detectors
+ contrast_enhancement/index
+
diff --git a/develop/doc/html/_sources/index.rst.txt b/develop/doc/html/_sources/index.rst.txt
index 2a52bd6fa..71bdcf120 100644
--- a/develop/doc/html/_sources/index.rst.txt
+++ b/develop/doc/html/_sources/index.rst.txt
@@ -26,6 +26,7 @@ Core Library Documentation
design/index
image_processing/index
+ histogram/index
API Reference <./reference/index.html#://>
Extensions Documentation
@@ -37,6 +38,7 @@ Extensions Documentation
io
toolbox
numeric
+ histogram/extension/index
Examples
--------
diff --git a/develop/doc/html/design/basics.html b/develop/doc/html/design/basics.html
index bc60ea02d..5f4ea0295 100644
--- a/develop/doc/html/design/basics.html
+++ b/develop/doc/html/design/basics.html
@@ -114,7 +114,7 @@ read the sections in order.
diff --git a/develop/doc/html/design/channel.html b/develop/doc/html/design/channel.html
index 31bb8b297..7c9f3cb34 100644
--- a/develop/doc/html/design/channel.html
+++ b/develop/doc/html/design/channel.html
@@ -263,7 +263,7 @@ channel-level algorithms that GIL provides: