add CvChain#approx_chains

ext/opencv/cvchain.cpp

@@ -20,7 +20,7 @@ __NAMESPACE_BEGIN_CVCHAIN
 #define APPROX_CHAIN_OPTION(op) rb_get_option_table(rb_klass, "APPROX_CHAIN_OPTION", op)
 #define APPROX_CHAIN_METHOD(op) CVMETHOD("APPROX_CHAIN_METHOD", LOOKUP_CVMETHOD(op, "method"), CV_CHAIN_APPROX_SIMPLE)
 #define APPROX_CHAIN_PARAMETER(op) NUM2INT(LOOKUP_CVMETHOD(op, "parameter"))
-#define APPROX_CHAIN_MINIMAL_PARAMETER(op) NUM2INT(LOOKUP_CVMETHOD(op, "minimal_parameter"))
+#define APPROX_CHAIN_MINIMAL_PERIMETER(op) NUM2INT(LOOKUP_CVMETHOD(op, "minimal_perimeter"))
 #define APPROX_CHAIN_RECURSIVE(op) TRUE_OR_FALSE(LOOKUP_CVMETHOD(op, "recursive"))
 
 VALUE rb_klass;
@@ -52,7 +52,7 @@ define_ruby_class()
   rb_define_const(rb_klass, "APPROX_CHAIN_OPTION", approx_chain_option); 
   rb_hash_aset(approx_chain_option, ID2SYM(rb_intern("method")), ID2SYM(rb_intern("approx_simple")));
   rb_hash_aset(approx_chain_option, ID2SYM(rb_intern("parameter")), rb_float_new(0));
-  rb_hash_aset(approx_chain_option, ID2SYM(rb_intern("minimal_parameter")), INT2FIX(0));
+  rb_hash_aset(approx_chain_option, ID2SYM(rb_intern("minimal_perimeter")), INT2FIX(0));
   rb_hash_aset(approx_chain_option, ID2SYM(rb_intern("recursive")), Qfalse);
 
   rb_define_private_method(rb_klass, "initialize", RUBY_METHOD_FUNC(rb_initialize), -1);
@@ -60,8 +60,8 @@ define_ruby_class()
   rb_define_method(rb_klass, "origin=", RUBY_METHOD_FUNC(rb_set_origin), 1);
   rb_define_method(rb_klass, "codes", RUBY_METHOD_FUNC(rb_codes), 0);
   rb_define_method(rb_klass, "points", RUBY_METHOD_FUNC(rb_points), 0);
-  rb_define_method(rb_klass, "approx_chain", RUBY_METHOD_FUNC(rb_approx_chain), -1);
+  rb_define_method(rb_klass, "approx_chains", RUBY_METHOD_FUNC(rb_approx_chains), -1);
-  rb_define_alias(rb_klass, "approx", "approx_chain");
+  rb_define_alias(rb_klass, "approx", "approx_chains");
 }
 
 VALUE
@@ -172,7 +172,7 @@ rb_points(VALUE self)
 
 /*
  * call-seq:
- *   approx_chain(<i>[approx_chain_option]</i>) -> cvcontour
+ *   approx_chains(<i>[approx_chain_option]</i>) -> cvcontour
  *
  * Approximates Freeman chain(s) with polygonal curve.
  * <i>approx_chain_option</i> should be Hash include these keys.
@@ -193,21 +193,22 @@ rb_points(VALUE self)
  *
  */
 VALUE
-rb_approx_chain(int argc, VALUE *argv, VALUE self)
+rb_approx_chains(int argc, VALUE *argv, VALUE self)
 {
-  VALUE approx_chain_option, storage;
+  VALUE approx_chain_option;
   rb_scan_args(argc, argv, "01", &approx_chain_option);
+
   approx_chain_option = APPROX_CHAIN_OPTION(approx_chain_option);
-  /* can't compile VC
+  VALUE storage = cCvMemStorage::new_object();
-  storage = cCvMemStorage::new_object();
   CvSeq *seq = cvApproxChains(CVSEQ(self), CVMEMSTORAGE(storage),			      
 			      APPROX_CHAIN_METHOD(approx_chain_option),
-			      APPROX_CHAIN_PARAMETER(approx_chain_option),			    
+			      APPROX_CHAIN_PARAMETER(approx_chain_option),
-			      APPROX_CHAIN_MINIMAL_PARAMETER(approx_chain_option),			      
+			      APPROX_CHAIN_MINIMAL_PERIMETER(approx_chain_option),
 			      APPROX_CHAIN_RECURSIVE(approx_chain_option));
-  
+
-  return cCvSeq::new_sequence(cCvContour::rb_class(), seq, cCvPoint::rb_class(), storage);
+  if (seq && seq->total > 0) {
-  */
+    return cCvSeq::new_sequence(cCvChain::rb_class(), seq, cCvPoint::rb_class(), storage);
+  }
   return Qnil;
 }
 

ext/opencv/cvchain.h

@@ -28,7 +28,7 @@ VALUE rb_origin(VALUE self);
 VALUE rb_set_origin(VALUE self, VALUE origin);
 VALUE rb_codes(VALUE self);
 VALUE rb_points(VALUE self);
-VALUE rb_approx_chain(int argc, VALUE *argv, VALUE self);
+VALUE rb_approx_chains(int argc, VALUE *argv, VALUE self);
 
 VALUE new_object();
 

test/test_cvchain.rb

@@ -54,8 +54,55 @@ class TestCvChain < OpenCVTestCase
     assert(chain.points.all? { |a| a.class == CvPoint })
   end
 
-  def test_approx_chain
+  def test_approx_chains
-    flunk('FIXME: CvChain#approx_chain is not implemented yet.')
+    mat0 = create_cvmat(128, 128, :cv8u, 1) { |j, i|
+      (j - 64) ** 2 + (i - 64) ** 2 <= (32 ** 2) ? CvColor::White : CvColor::Black
+    }
+    chain = mat0.find_contours(:mode => CV_RETR_EXTERNAL, :method => CV_CHAIN_CODE)
+
+    contours = chain.approx_chains
+    assert_equal(CvChain, contours.class)
+    assert(contours.size > 0)
+    assert(contours.all? { |c| c.class == CvPoint })
+
+    [CV_CHAIN_APPROX_NONE, CV_CHAIN_APPROX_SIMPLE,
+     CV_CHAIN_APPROX_TC89_L1, CV_CHAIN_APPROX_TC89_KCOS,
+     :approx_none, :approx_simple, :approx_tc89_l1, :approx_tc89_kcos].each { |method|
+      contours = chain.approx_chains(:method => method)
+      assert_equal(CvChain, contours.class)
+      assert(contours.size > 0)
+      assert(contours.all? { |c| c.class == CvPoint })
+    }
+
+    contours = chain.approx_chains(:minimal_parameter => 10)
+    assert_equal(CvChain, contours.class)
+    assert(contours.size > 0)
+    assert(contours.all? { |c| c.class == CvPoint })
+
+    contours = chain.approx_chains(:minimal_perimeter => (32 * 2 * Math::PI).ceil)
+    assert_nil(contours)
+
+    [true, false].each { |recursive|
+      contours = chain.approx_chains(:recursive => recursive)
+      assert_equal(CvChain, contours.class)
+      assert(contours.size > 0)
+      assert(contours.all? { |c| c.class == CvPoint })
+    }
+
+    contours = chain.approx_chains(:method => :approx_simple,
+                                  :minimal_parameter => 100, :recursive => false)
+    assert_equal(CvChain, contours.class)
+    assert(contours.size > 0)
+    assert(contours.all? { |c| c.class == CvPoint })
+
+    # Uncomment the following lines to show the result
+    # contours = chain.approx_chains
+    # dst = mat0.clone.zero
+    # begin
+    #   dst.draw_contours!(contours, CvColor::White, CvColor::Black, 2,
+    #                      :thickness => 1, :line_type => :aa)
+    # end while (contours = contours.h_next)
+    # snap dst
   end
 end