fix IplImage#split to return Array<IplImage> (Issue #7)

https://github.com/ruby-opencv/ruby-opencv/issues/7

ext/opencv/cvmat.cpp

@@ -1588,22 +1588,25 @@ rb_flip_bang(int argc, VALUE *argv, VALUE self)
 VALUE
 rb_split(VALUE self)
 {
-  CvMat* self_ptr = CVMAT(self);
+  CvArr* self_ptr = CVARR(self);
-  int type = self_ptr->type, depth = CV_MAT_DEPTH(type), channel = CV_MAT_CN(type);
+  int type = cvGetElemType(self_ptr);
-  CvMat *dest[] = { NULL, NULL, NULL, NULL };
+  int depth = CV_MAT_DEPTH(type), channel = CV_MAT_CN(type);
+  VALUE dest = rb_ary_new2(channel);
   try {
+    CvArr *dest_ptr[] = { NULL, NULL, NULL, NULL };
     CvSize size = cvGetSize(self_ptr);
-    for (int i = 0; i < channel; ++i)
+    for (int i = 0; i < channel; ++i) {
-      dest[i] = rb_cvCreateMat(size.height, size.width, CV_MAKETYPE(depth, 1));
+      VALUE tmp = new_mat_kind_object(size, self, depth, 1);
-    cvSplit(self_ptr, dest[0], dest[1], dest[2], dest[3]);
+      rb_ary_store(dest, i, tmp);
+      dest_ptr[i] = CVARR(tmp);
+    }
+    cvSplit(self_ptr, dest_ptr[0], dest_ptr[1], dest_ptr[2], dest_ptr[3]);
   }
   catch (cv::Exception& e) {
     raise_cverror(e);
   }
-  VALUE ary = rb_ary_new2(channel);
+
-  for (int i = 0; i < channel; ++i)
+  return dest;
-    rb_ary_store(ary, i, OPENCV_OBJECT(rb_klass, dest[i]));
-  return ary;
 }
 
 /*

test/helper.rb

@@ -99,6 +99,19 @@ class OpenCVTestCase < Test::Unit::TestCase
     m
   end
 
+  def create_iplimage(width, height, depth = :cv8u, channel = 4, &block)
+    m = IplImage.new(width, height, depth, channel)
+    block = lambda { |j, i, c| CvScalar.new(*([c + 1] * channel)) } unless block_given?
+    count = 0
+    height.times { |j|
+      width.times { |i|
+        m[j, i] = block.call(j, i, count)
+        count += 1
+      }
+    }
+    m
+  end
+
   def assert_each_cvscalar(actual, delta = 0, &block)
     raise unless block_given?
     count = 0

test/test_cvmat.rb

@@ -826,9 +826,14 @@ class TestCvMat < OpenCVTestCase
     m0 = create_cvmat(2, 3, :cv8u, 3) { |j, i, c|
       CvScalar.new(c * 10, c * 20, c * 30)
     }
-    m0.split.each_with_index { |m, idx|
+
+    splitted = m0.split
+    assert_equal(m0.channel, splitted.size)
+    splitted.each_with_index { |m, idx|
+      assert_equal(CvMat, m.class)
       assert_equal(m0.height, m.height)
       assert_equal(m0.width, m.width)
+      assert_equal(1, m.channel)
 
       c = 0
       m0.height.times { |j|
@@ -839,6 +844,27 @@ class TestCvMat < OpenCVTestCase
         }
       }
     }
+
+    # IplImage#split should return Array<IplImage>
+    image = create_iplimage(2, 3, :cv8u, 3) { |j, i, c|
+      CvScalar.new(c * 10, c * 20, c * 30)
+    }
+
+    splitted = image.split
+    assert_equal(3, splitted.size)
+    splitted.each_with_index { |img, channel|
+      assert_equal(IplImage, img.class)
+      assert_equal(image.height, img.height)
+      assert_equal(image.width, img.width)
+      assert_equal(1, img.channel)
+
+      img.height.times { |j|
+        img.width.times { |i|
+          val = image[j, i][channel]
+          assert_cvscalar_equal(CvScalar.new(val), img[j, i])
+        }
+      }
+    }
   end
 
   def test_merge