diff --git a/ext/opencv/cvmat.cpp b/ext/opencv/cvmat.cpp
index 40f1a23..cf3f441 100644
--- a/ext/opencv/cvmat.cpp
+++ b/ext/opencv/cvmat.cpp
@@ -3915,14 +3915,14 @@ rb_quadrangle_sub_pix(int argc, VALUE *argv, VALUE self)
  *
  * Resize image.
  * <i>interpolation</i> is interpolation method:
- * * :nn
+ * * CV_INTER_NN
  *   nearest-neighbor interpolation.
- * * :linear
+ * * CV_INTER_LINEAR
  *   bilinear interpolation (used by default)
- * * :area
+ * * CV_INTER_AREA
  *   resampling using pixel area relation. It is preferred method for image decimation that give moire-free results.
  *   In case of zooming it is similar to NN method.
- * * :cubic
+ * * CV_INTER_CUBIC
  *   bicubic interpolation.
  * Return <i>self</i> resized image that it fits exactly to <i>size</i>. If ROI is set, the method consideres the ROI as supported as usual.
  */
@@ -3932,8 +3932,10 @@ rb_resize(int argc, VALUE *argv, VALUE self)
   VALUE size, interpolation;
   rb_scan_args(argc, argv, "11", &size, &interpolation);
   VALUE dest = new_mat_kind_object(VALUE_TO_CVSIZE(size), self);
+  int method = NIL_P(interpolation) ? CV_INTER_LINEAR : NUM2INT(interpolation);
+
   try {
-    cvResize(CVARR(self), CVARR(dest), CVMETHOD("INTERPOLATION_METHOD", interpolation, CV_INTER_LINEAR));
+    cvResize(CVARR(self), CVARR(dest), method);
   }
   catch (cv::Exception& e) {
     raise_cverror(e);
@@ -3943,7 +3945,7 @@ rb_resize(int argc, VALUE *argv, VALUE self)
 
 /*
  * call-seq:
- *   warp_affine(<i>map_matrix[,interpolation = :linear][,option = :fill_outliers][,fillval = 0]</i>) -> cvmat
+ *   warp_affine(<i>map_matrix[,interpolation = CV_INTER_LINEAR][,option = :fill_outliers][,fillval = 0]</i>) -> cvmat
  *
  * Applies affine transformation to the image.
  */
@@ -3955,11 +3957,12 @@ rb_warp_affine(int argc, VALUE *argv, VALUE self)
   if (rb_scan_args(argc, argv, "13", &map_matrix, &interpolation, &option, &fill_value) < 4)
     fill_value = INT2FIX(0);
   CvArr* self_ptr = CVARR(self);
+  int method = NIL_P(interpolation) ? CV_INTER_LINEAR : NUM2INT(interpolation);
   try {
     dest = new_mat_kind_object(cvGetSize(self_ptr), self);
     cvWarpAffine(self_ptr, CVARR(dest), CVMAT_WITH_CHECK(map_matrix),
-		 CVMETHOD("INTERPOLATION_METHOD", interpolation, CV_INTER_LINEAR)
-		 | CVMETHOD("WARP_FLAG", option, CV_WARP_FILL_OUTLIERS), VALUE_TO_CVSCALAR(fill_value));
+		 method | CVMETHOD("WARP_FLAG", option, CV_WARP_FILL_OUTLIERS),
+		 VALUE_TO_CVSCALAR(fill_value));
   }
   catch (cv::Exception& e) {
     raise_cverror(e);
@@ -4047,7 +4050,7 @@ rb_rotation_matrix2D(VALUE self, VALUE center, VALUE angle, VALUE scale)
 
 /*
  * call-seq:
- *   warp_perspective(<i>map_matrix[,interpolation=:linear][,option =:fill_outliers][,fillval=0])</i>) -> cvmat
+ *   warp_perspective(<i>map_matrix[,interpolation=CV_INTER_LINEAR][,option =:fill_outliers][,fillval=0])</i>) -> cvmat
  *
  * Applies perspective transformation to the image.
  */
@@ -4059,11 +4062,11 @@ rb_warp_perspective(int argc, VALUE *argv, VALUE self)
     fillval = INT2FIX(0);
   CvArr* self_ptr = CVARR(self);
   VALUE dest = Qnil;
+  int method = NIL_P(interpolation) ? CV_INTER_LINEAR : NUM2INT(interpolation);
   try {
     dest = new_mat_kind_object(cvGetSize(self_ptr), self);
     cvWarpPerspective(self_ptr, CVARR(dest), CVMAT_WITH_CHECK(map_matrix),
-		      CVMETHOD("INTERPOLATION_METHOD", interpolation, CV_INTER_LINEAR)
-		      | CVMETHOD("WARP_FLAG",option, CV_WARP_FILL_OUTLIERS),
+		      method | CVMETHOD("WARP_FLAG",option, CV_WARP_FILL_OUTLIERS),
 		      VALUE_TO_CVSCALAR(fillval));
   }
   catch (cv::Exception& e) {
@@ -4074,7 +4077,7 @@ rb_warp_perspective(int argc, VALUE *argv, VALUE self)
 
 /*
  * call-seq:
- *   remap(<i>mapx,mapy[,interpolation=:linear][,option=:fill_outliers][,fillval=0]</i>) -> cvmat
+ *   remap(<i>mapx,mapy[,interpolation=CV_INTER_LINEAR][,option=:fill_outliers][,fillval=0]</i>) -> cvmat
  *
  * Applies generic geometrical transformation to the image.
  * Transforms source image using the specified map:
@@ -4090,11 +4093,11 @@ rb_remap(int argc, VALUE *argv, VALUE self)
     fillval = INT2FIX(0);
   CvArr* self_ptr = CVARR(self);
   VALUE dest = Qnil;
+  int method = NIL_P(interpolation) ? CV_INTER_LINEAR : NUM2INT(interpolation);
   try {
     dest = new_mat_kind_object(cvGetSize(self_ptr), self);
     cvRemap(self_ptr, CVARR(dest), CVARR_WITH_CHECK(mapx), CVARR_WITH_CHECK(mapy),
-	    CVMETHOD("INTERPOLATION_METHOD", interpolation, CV_INTER_LINEAR)
-	    | CVMETHOD("WARP_FLAG", option, CV_WARP_FILL_OUTLIERS),
+	    method | CVMETHOD("WARP_FLAG", option, CV_WARP_FILL_OUTLIERS),
 	    VALUE_TO_CVSCALAR(fillval));
   }
   catch (cv::Exception& e) {
diff --git a/ext/opencv/opencv.cpp b/ext/opencv/opencv.cpp
index 944132d..d7d3863 100644
--- a/ext/opencv/opencv.cpp
+++ b/ext/opencv/opencv.cpp
@@ -294,7 +294,7 @@ define_ruby_module()
   rb_define_const(rb_module, "CV_INTER_LINEAR", INT2FIX(CV_INTER_LINEAR));
   rb_define_const(rb_module, "CV_INTER_AREA", INT2FIX(CV_INTER_AREA));
   rb_define_const(rb_module, "CV_INTER_CUBIC", INT2FIX(CV_INTER_CUBIC));
-  
+
   /* Warp affine optional flags */
   rb_define_const(rb_module, "CV_WARP_FILL_OUTLIERS", INT2FIX(CV_WARP_FILL_OUTLIERS));
   rb_define_const(rb_module, "CV_WARP_INVERSE_MAP", INT2FIX(CV_WARP_INVERSE_MAP));
@@ -345,14 +345,6 @@ define_ruby_module()
   REGISTER_CVMETHOD(inversion_method, "svd_sym", CV_SVD_SYM);
   REGISTER_CVMETHOD(inversion_method, "svd_symmetric", CV_SVD_SYM);
     
-  VALUE interpolation_method = rb_hash_new();
-  /* {:nn, :linear, :area, :cubic}: Interpolation method */
-  rb_define_const(rb_module, "INTERPOLATION_METHOD", interpolation_method);
-  REGISTER_CVMETHOD(interpolation_method, "nn", CV_INTER_NN);
-  REGISTER_CVMETHOD(interpolation_method, "linear", CV_INTER_LINEAR);
-  REGISTER_CVMETHOD(interpolation_method, "area", CV_INTER_AREA);
-  REGISTER_CVMETHOD(interpolation_method, "cubic", CV_INTER_CUBIC);
-  
   VALUE warp_flag = rb_hash_new();
   /* {:fill_outliers, :inverse_map}: Warp affine optional flags */
   rb_define_const(rb_module, "WARP_FLAG", warp_flag);
diff --git a/test/test_cvmat_imageprocessing.rb b/test/test_cvmat_imageprocessing.rb
index 573c0a1..9d1266d 100755
--- a/test/test_cvmat_imageprocessing.rb
+++ b/test/test_cvmat_imageprocessing.rb
@@ -388,10 +388,10 @@ class TestCvMat_imageprocessing < OpenCVTestCase
     size_512 = CvSize.new(512, 512)
     size_128 = CvSize.new(128, 128)
     mat1 = mat0.resize(size_512)
-    mat2 = mat0.resize(size_512, :linear)
-    mat3 = mat0.resize(size_512, :nn)
-    mat4 = mat0.resize(size_128, :area)
-    mat5 = mat0.resize(size_128, :cubic)
+    mat2 = mat0.resize(size_512, CV_INTER_LINEAR)
+    mat3 = mat0.resize(size_512, CV_INTER_NN)
+    mat4 = mat0.resize(size_128, CV_INTER_AREA)
+    mat5 = mat0.resize(size_128, CV_INTER_CUBIC)
     mat6 = mat0.clone
 
     assert_equal('b2203ccca2c17b042a90b79704c0f535', hash_img(mat1))
@@ -420,9 +420,9 @@ class TestCvMat_imageprocessing < OpenCVTestCase
     map_matrix[5] = CvScalar.new(66.08774)
 
     mat1 = mat0.warp_affine(map_matrix)
-    mat2 = mat0.warp_affine(map_matrix, :nn)
-    mat3 = mat0.warp_affine(map_matrix, :linear, :fill_outliers, CvColor::Yellow)
-    mat4 = mat0.warp_affine(map_matrix, :linear, :inverse_map)
+    mat2 = mat0.warp_affine(map_matrix, CV_INTER_NN)
+    mat3 = mat0.warp_affine(map_matrix, CV_INTER_LINEAR, :fill_outliers, CvColor::Yellow)
+    mat4 = mat0.warp_affine(map_matrix, CV_INTER_LINEAR, :inverse_map)
     
     assert_equal('da3d7cdefabbaf84c4080ecd40d00897', hash_img(mat1))
     assert_equal('b4abcd12c4e1103c3de87bf9ad854936', hash_img(mat2))
@@ -483,9 +483,9 @@ class TestCvMat_imageprocessing < OpenCVTestCase
     map_matrix[8] = CvScalar.new(1.00000)
     
     mat1 = mat0.warp_perspective(map_matrix)
-    mat2 = mat0.warp_perspective(map_matrix, :nn)
-    mat3 = mat0.warp_perspective(map_matrix, :linear, :inverse_map)
-    mat4 = mat0.warp_perspective(map_matrix, :linear, :fill_outliers, CvColor::Yellow)
+    mat2 = mat0.warp_perspective(map_matrix, CV_INTER_NN)
+    mat3 = mat0.warp_perspective(map_matrix, CV_INTER_LINEAR, :inverse_map)
+    mat4 = mat0.warp_perspective(map_matrix, CV_INTER_LINEAR, :fill_outliers, CvColor::Yellow)
 
     assert_equal('bba3a5395f9dd9a400a0083ae74d8986', hash_img(mat1))
     assert_equal('a0cc4f329f459410293b75b417fc4f25', hash_img(mat2))
@@ -522,8 +522,8 @@ class TestCvMat_imageprocessing < OpenCVTestCase
     }
 
     mat1 = mat0.remap(matx, maty)
-    mat2 = mat0.remap(matx, maty, :nn)
-    mat3 = mat0.remap(matx, maty, :linear, :fill_outliers, CvColor::Yellow)
+    mat2 = mat0.remap(matx, maty, CV_INTER_NN)
+    mat3 = mat0.remap(matx, maty, CV_INTER_LINEAR, :fill_outliers, CvColor::Yellow)
 
     assert_equal('586716c0262a3e03a54b9fc6e671e5f7', hash_img(mat1))
     assert_equal('5461ecdee23d5e8a9099500d631c9f0f', hash_img(mat2))