diff --git a/ext/opencv/mat.cpp b/ext/opencv/mat.cpp
index da0da4b..bd2eb69 100644
--- a/ext/opencv/mat.cpp
+++ b/ext/opencv/mat.cpp
@@ -1247,6 +1247,7 @@ namespace rubyopencv {
       rb_define_method(rb_klass, "rectangle!", RUBY_METHOD_FUNC(rb_rectangle_bang), -1); // in ext/opencv/mat_drawing.cpp
 
       rb_define_method(rb_klass, "resize", RUBY_METHOD_FUNC(rb_resize), -1); // in ext/opencv/mat_imgproc.cpp
+      rb_define_method(rb_klass, "resize!", RUBY_METHOD_FUNC(rb_resize_bang), -1); // in ext/opencv/mat_imgproc.cpp
       rb_define_method(rb_klass, "cvt_color", RUBY_METHOD_FUNC(rb_cvt_color), -1); // in ext/opencv/mat_imgproc.cpp
       rb_define_method(rb_klass, "blur", RUBY_METHOD_FUNC(rb_blur), -1); // in ext/opencv/mat_imgproc.cpp
       rb_define_method(rb_klass, "gaussian_blur", RUBY_METHOD_FUNC(rb_gaussian_blur), -1); // in ext/opencv/mat_imgproc.cpp
diff --git a/ext/opencv/mat_imgproc.cpp b/ext/opencv/mat_imgproc.cpp
index 249561b..d51971e 100644
--- a/ext/opencv/mat_imgproc.cpp
+++ b/ext/opencv/mat_imgproc.cpp
@@ -186,6 +186,20 @@ namespace rubyopencv {
       return mat2obj(destptr, CLASS_OF(self));
     }
 
+    cv::Mat* rb_resize_internal(int argc, VALUE *argv, VALUE self, cv::Mat* destptr) {
+      VALUE size, inv_scale_x, inv_scale_y, interpolation;
+      rb_scan_args(argc, argv, "13", &size, &inv_scale_x, &inv_scale_y, &interpolation);
+      cv::Size* sizeptr = Size::obj2size(size);
+      cv::Mat* selfptr = obj2mat(self);
+      double sx = NIL_P(inv_scale_x) ? 0 : NUM2DBL(inv_scale_x);
+      double sy = NIL_P(inv_scale_y) ? 0 : NUM2DBL(inv_scale_y);
+      int method = NIL_P(interpolation) ? CV_INTER_LINEAR : NUM2INT(interpolation);
+
+      cv::resize(*selfptr, *destptr, *sizeptr, sx, sy, method);
+
+      return destptr;
+    }
+
     /*
      * Resizes an image.
      *
@@ -203,17 +217,9 @@ namespace rubyopencv {
      * @opencv_func cv::Resize
      */
     VALUE rb_resize(int argc, VALUE *argv, VALUE self) {
-      VALUE size, inv_scale_x, inv_scale_y, interpolation;
-      rb_scan_args(argc, argv, "13", &size, &inv_scale_x, &inv_scale_y, &interpolation);
-      cv::Size* sizeptr = Size::obj2size(size);
-      cv::Mat* selfptr = obj2mat(self);
       cv::Mat* destptr = new cv::Mat();
-      double sx = NIL_P(inv_scale_x) ? 0 : NUM2DBL(inv_scale_x);
-      double sy = NIL_P(inv_scale_y) ? 0 : NUM2DBL(inv_scale_y);
-      int method = NIL_P(interpolation) ? CV_INTER_LINEAR : NUM2INT(interpolation);
-
       try {
-	cv::resize(*selfptr, *destptr, *sizeptr, sx, sy, method);
+	rb_resize_internal(argc, argv, self, destptr);
       }
       catch (cv::Exception& e) {
 	delete destptr;
@@ -223,6 +229,34 @@ namespace rubyopencv {
       return mat2obj(destptr, CLASS_OF(self));
     }
 
+    /*
+     * Resizes an image.
+     *
+     * @overload resize(size, interpolation = INTER_LINEAR)
+     *   @param size [Size] Output image size.
+     *   @param interpolation [Integer] Interpolation method:
+     *     * <tt>INTER_NEAREST</tt> - A nearest-neighbor interpolation
+     *	   * <tt>INTER_LINEAR</tt> - A bilinear interpolation (used by default)
+     *	   * <tt>INTER_AREA</tt> - Resampling using pixel area relation. It may be a preferred method for
+     *       image decimation, as it gives moire'-free results. But when the image is zoomed,
+     *       it is similar to the <tt>INTER_NEAREST</tt> method.
+     *     * <tt>INTER_CUBIC</tt> - A bicubic interpolation over 4x4 pixel neighborhood
+     *	   * <tt>INTER_LANCZOS4</tt> - A Lanczos interpolation over 8x8 pixel neighborhood
+     * @return [Mat] Output image.
+     * @opencv_func cv::Resize
+     */
+    VALUE rb_resize_bang(int argc, VALUE *argv, VALUE self) {
+      cv::Mat* destptr = obj2mat(self);
+      try {
+	rb_resize_internal(argc, argv, self, destptr);
+      }
+      catch (cv::Exception& e) {
+	Error::raise(e);
+      }
+
+      return self;
+    }
+
     /*
      * Blurs an image using the normalized box filter.
      *
diff --git a/ext/opencv/mat_imgproc.hpp b/ext/opencv/mat_imgproc.hpp
index 5583f97..58c01d5 100644
--- a/ext/opencv/mat_imgproc.hpp
+++ b/ext/opencv/mat_imgproc.hpp
@@ -13,6 +13,7 @@ namespace rubyopencv {
     VALUE rb_laplacian(int argc, VALUE *argv, VALUE self);
     VALUE rb_cvt_color(int argc, VALUE *argv, VALUE self);
     VALUE rb_resize(int argc, VALUE *argv, VALUE self);
+    VALUE rb_resize_bang(int argc, VALUE *argv, VALUE self);
     VALUE rb_blur(int argc, VALUE *argv, VALUE self);
     VALUE rb_gaussian_blur(int argc, VALUE *argv, VALUE self);
     VALUE rb_median_blur(VALUE self, VALUE ksize);
diff --git a/test/test_mat.rb b/test/test_mat.rb
index 5e2a957..c86cf0c 100755
--- a/test/test_mat.rb
+++ b/test/test_mat.rb
@@ -480,32 +480,6 @@ class TestMat < OpenCVTestCase
     }
   end
 
-  def test_resize
-    m0 = Mat.ones(200, 300, CV_8U)
-    s = Size.new(150, 100)
-
-    m = m0.resize(s)
-    assert_equal(s.height, m.rows)
-    assert_equal(s.width, m.cols)
-    assert_equal(m0.depth, m.depth)
-    assert_equal(m0.dims, m.dims)
-    assert_equal(m0.channels, m.channels)
-
-    [INTER_NEAREST, INTER_LINEAR, INTER_AREA,
-     INTER_CUBIC, INTER_LANCZOS4].each { |interpolation|
-      m = m0.resize(s, interpolation)
-      assert_equal(s.height, m.rows)
-      assert_equal(s.width, m.cols)
-      assert_equal(m0.depth, m.depth)
-      assert_equal(m0.dims, m.dims)
-      assert_equal(m0.channels, m.channels)
-    }
-
-    assert_raise(TypeError) {
-      m.resize(DUMMY_OBJ)
-    }
-  end 
-
   def test_diag
     m0 = Mat.new(3, 3, CV_8U)
     i = 1
diff --git a/test/test_mat_imgproc.rb b/test/test_mat_imgproc.rb
index 644b6cb..209fddf 100755
--- a/test/test_mat_imgproc.rb
+++ b/test/test_mat_imgproc.rb
@@ -6,6 +6,60 @@ require File.expand_path(File.dirname(__FILE__)) + '/helper'
 include Cv
 
 class TestCvMat < OpenCVTestCase
+  def test_resize
+    m0 = Mat.ones(200, 300, CV_8U)
+    s = Size.new(150, 100)
+
+    m = m0.resize(s)
+    assert_equal(s.height, m.rows)
+    assert_equal(s.width, m.cols)
+    assert_equal(m0.depth, m.depth)
+    assert_equal(m0.dims, m.dims)
+    assert_equal(m0.channels, m.channels)
+
+    [INTER_NEAREST, INTER_LINEAR, INTER_AREA,
+     INTER_CUBIC, INTER_LANCZOS4].each { |interpolation|
+      m = m0.resize(s, interpolation)
+      assert_equal(s.height, m.rows)
+      assert_equal(s.width, m.cols)
+      assert_equal(m0.depth, m.depth)
+      assert_equal(m0.dims, m.dims)
+      assert_equal(m0.channels, m.channels)
+    }
+
+    assert_raise(TypeError) {
+      m.resize(DUMMY_OBJ)
+    }
+  end
+
+  def test_resize_bang
+    m0 = Mat.ones(200, 300, CV_8U)
+    m = m0.clone
+    s = Size.new(150, 100)
+
+    m.resize!(s)
+    assert_equal(s.height, m.rows)
+    assert_equal(s.width, m.cols)
+    assert_equal(m0.depth, m.depth)
+    assert_equal(m0.dims, m.dims)
+    assert_equal(m0.channels, m.channels)
+
+    [INTER_NEAREST, INTER_LINEAR, INTER_AREA,
+     INTER_CUBIC, INTER_LANCZOS4].each { |interpolation|
+      m = m0.clone
+      m.resize!(s, interpolation)
+      assert_equal(s.height, m.rows)
+      assert_equal(s.width, m.cols)
+      assert_equal(m0.depth, m.depth)
+      assert_equal(m0.dims, m.dims)
+      assert_equal(m0.channels, m.channels)
+    }
+
+    assert_raise(TypeError) {
+      m.resize!(DUMMY_OBJ)
+    }
+  end
+
   def test_sobel
     m0 = Cv::imread(FILENAME_LENA256x256, 0)