diff --git a/dlib/geometry/point_transforms.h b/dlib/geometry/point_transforms.h
index 1c939a2b1..7bb2c7032 100644
--- a/dlib/geometry/point_transforms.h
+++ b/dlib/geometry/point_transforms.h
@@ -19,6 +19,13 @@ namespace dlib
     class point_rotator
     {
     public:
+        point_rotator (
+        )
+        {
+            sin_angle = 0;
+            cos_angle = 1;
+        }
+
         point_rotator (
             const double& angle
         )
@@ -47,6 +54,18 @@ namespace dlib
             return temp; 
         }
 
+        inline friend void serialize (const point_rotator& item, std::ostream& out)
+        {
+            serialize(item.sin_angle, out);
+            serialize(item.cos_angle, out);
+        }
+
+        inline friend void deserialize (point_rotator& item, std::istream& in)
+        {
+            deserialize(item.sin_angle, in);
+            deserialize(item.cos_angle, in);
+        }
+
     private:
         double sin_angle;
         double cos_angle;
@@ -57,6 +76,16 @@ namespace dlib
     class point_transform
     {
     public:
+
+        point_transform (
+        )
+        {
+            sin_angle = 0;
+            cos_angle = 1;
+            translate.x() = 0;
+            translate.y() = 0;
+        }
+
         point_transform (
             const double& angle,
             const dlib::vector<double,2>& translate_
@@ -90,6 +119,20 @@ namespace dlib
         const dlib::vector<double,2> get_b(
         ) const { return translate; }
 
+        inline friend void serialize (const point_transform& item, std::ostream& out)
+        {
+            serialize(item.sin_angle, out);
+            serialize(item.cos_angle, out);
+            serialize(item.translate, out);
+        }
+
+        inline friend void deserialize (point_transform& item, std::istream& in)
+        {
+            deserialize(item.sin_angle, in);
+            deserialize(item.cos_angle, in);
+            deserialize(item.translate, in);
+        }
+
     private:
         double sin_angle;
         double cos_angle;
@@ -101,6 +144,15 @@ namespace dlib
     class point_transform_affine
     {
     public:
+
+        point_transform_affine (
+        )
+        {
+            m = identity_matrix<double>(2);
+            b.x() = 0;
+            b.y() = 0;
+        }
+
         point_transform_affine (
             const matrix<double,2,2>& m_,
             const dlib::vector<double,2>& b_
@@ -121,6 +173,18 @@ namespace dlib
         const dlib::vector<double,2>& get_b(
         ) const { return b; }
 
+        inline friend void serialize (const point_transform_affine& item, std::ostream& out)
+        {
+            serialize(item.m, out);
+            serialize(item.b, out);
+        }
+
+        inline friend void deserialize (point_transform_affine& item, std::istream& in)
+        {
+            deserialize(item.m, in);
+            deserialize(item.b, in);
+        }
+
     private:
         matrix<double,2,2> m;
         dlib::vector<double,2> b;
@@ -175,6 +239,13 @@ namespace dlib
     class point_transform_projective
     {
     public:
+
+        point_transform_projective (
+        )
+        {
+            m = identity_matrix<double>(3);
+        }
+
         point_transform_projective (
             const matrix<double,3,3>& m_
         ) :m(m_)
@@ -208,6 +279,15 @@ namespace dlib
         const matrix<double,3,3>& get_m(
         ) const { return m; }
 
+        inline friend void serialize (const point_transform_projective& item, std::ostream& out)
+        {
+            serialize(item.m, out);
+        }
+
+        inline friend void deserialize (point_transform_projective& item, std::istream& in)
+        {
+            deserialize(item.m, in);
+        }
 
     private:
         matrix<double,3,3> m;
diff --git a/dlib/geometry/point_transforms_abstract.h b/dlib/geometry/point_transforms_abstract.h
index 5bcc361a3..9bc596ce3 100644
--- a/dlib/geometry/point_transforms_abstract.h
+++ b/dlib/geometry/point_transforms_abstract.h
@@ -20,6 +20,15 @@ namespace dlib
                 applies an affine transformation to them.
         !*/
     public:
+
+        point_transform_affine (
+        );
+        /*!
+            ensures
+                - This object will perform the identity transform.  That is, given a point
+                  as input it will return the same point as output.
+        !*/
+
         point_transform_affine (
             const matrix<double,2,2>& m,
             const dlib::vector<double,2>& b
@@ -57,6 +66,12 @@ namespace dlib
 
     };
 
+    void serialize   (const point_transform_affine& item, std::ostream& out);
+    void deserialize (point_transform_affine& item, std::istream& in);
+    /*!
+        provides serialization support
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
     point_transform_affine inv (
@@ -104,6 +119,14 @@ namespace dlib
 
     public:
 
+        point_transform_projective (
+        );
+        /*!
+            ensures
+                - This object will perform the identity transform.  That is, given a point
+                  as input it will return the same point as output.
+        !*/
+
         point_transform_projective (
             const matrix<double,3,3>& m
         );
@@ -145,6 +168,12 @@ namespace dlib
 
     };
 
+    void serialize   (const point_transform_projective& item, std::ostream& out);
+    void deserialize (point_transform_projective& item, std::istream& in);
+    /*!
+        provides serialization support
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
     point_transform_projective inv (
@@ -186,6 +215,15 @@ namespace dlib
                 translates them.
         !*/
     public:
+
+        point_transform (
+        );
+        /*!
+            ensures
+                - This object will perform the identity transform.  That is, given a point
+                  as input it will return the same point as output.
+        !*/
+
         point_transform (
             const double& angle,
             const dlib::vector<double,2>& translate
@@ -226,6 +264,12 @@ namespace dlib
 
     };
 
+    void serialize   (const point_transform& item, std::ostream& out);
+    void deserialize (point_transform& item, std::istream& in);
+    /*!
+        provides serialization support
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
     class point_rotator
@@ -236,6 +280,15 @@ namespace dlib
                 rotates them around the origin by a given angle.
         !*/
     public:
+
+        point_rotator (
+        );
+        /*!
+            ensures
+                - This object will perform the identity transform.  That is, given a point
+                  as input it will return the same point as output.
+        !*/
+
         point_rotator (
             const double& angle
         );
@@ -267,6 +320,12 @@ namespace dlib
         !*/
     };
 
+    void serialize   (const point_rotator& item, std::ostream& out);
+    void deserialize (point_rotator& item, std::istream& in);
+    /*!
+        provides serialization support
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
     template <typename T>
diff --git a/dlib/test/geometry.cpp b/dlib/test/geometry.cpp
index 50702181c..946c18e43 100644
--- a/dlib/test/geometry.cpp
+++ b/dlib/test/geometry.cpp
@@ -648,6 +648,14 @@ namespace
             DLIB_TEST(length(t(tinv(from[i]))-from[i]) < 1e-14);
         }
 
+        ostringstream sout;
+        serialize(t, sout);
+        istringstream sin(sout.str());
+        point_transform_affine t2;
+        DLIB_TEST(length(t2(point(2,3)) - point(2,3)) < 1e-14);
+        deserialize(t2, sin);
+        DLIB_TEST(max(abs(t2.get_m()-t.get_m())) < 1e-14);
+        DLIB_TEST(max(abs(t2.get_b()-t.get_b())) < 1e-14);
     }
 
 // ----------------------------------------------------------------------------------------
@@ -706,6 +714,14 @@ namespace
                 dlog << LINFO << " errors: mean/max: " << rs.mean() << "  " << rs.max();
                 pass_rate.add(0);
             }
+
+            ostringstream sout;
+            serialize(tran, sout);
+            istringstream sin(sout.str());
+            point_transform_projective tran3;
+            DLIB_TEST(length(tran3(point(2,3)) - point(2,3)) < 1e-14);
+            deserialize(tran3, sin);
+            DLIB_TEST(max(abs(tran3.get_m()-tran.get_m())) < 1e-14);
         }
 
         dlog << LINFO << " pass_rate.mean(): "<< pass_rate.mean();