Added subpixel tests

Use to make sure that the code still works and we are not receeding in
quality.

Interesting note that these tests have found. Our current Bayes EM
performs worse than Parabola on high slopes. The problem appears to be
Bayes's poorly implemented pyramid code. Removing that makes BayesEM
perform a lot better in the tests, however I'll need to compare with
real data else where.

.gitignore

@@ -206,6 +206,7 @@ docs/workbook/workbook.toc
 /src/vw/Stereo/tests/TestCorrelator
 /src/vw/Stereo/tests/TestDisparity
 /src/vw/Stereo/tests/TestStereoModel
+/src/vw/Stereo/tests/TestSubPixel
 /src/vw/tools/ba_test
 /src/vw/tools/ba_unit_test_data
 /src/vw/tools/bayer

src/vw/Stereo/tests/Makefile.am

@@ -14,8 +14,9 @@ if MAKE_MODULE_STEREO
 TestStereoModel_SOURCES  = TestStereoModel.cxx
 TestDisparity_SOURCES    = TestDisparity.cxx
 TestCorrelator_SOURCES   = TestCorrelator.cxx
+TestSubPixel_SOURCES     = TestSubPixel.cxx
 
-TESTS = TestStereoModel TestDisparity TestCorrelator
+TESTS = TestStereoModel TestDisparity TestCorrelator TestSubPixel
 
 #include $(top_srcdir)/config/instantiate.am
 

src/vw/Stereo/tests/TestSubPixel.cxx

@@ -0,0 +1,169 @@
+// __BEGIN_LICENSE__
+// Copyright (C) 2006-2010 United States Government as represented by
+// the Administrator of the National Aeronautics and Space Administration.
+// All Rights Reserved.
+// __END_LICENSE__
+
+
+// TestCorrelator.h
+#include <gtest/gtest.h>
+
+#include <vw/Image/UtilityViews.h>
+#include <vw/Stereo/CorrelatorView.h>
+#include <vw/Stereo/SubpixelView.h>
+#include <vw/Image/Transform.h>
+#include <vw/Image.h>  // write_image
+#include <vw/FileIO.h>
+
+#include <boost/random/linear_congruential.hpp>
+
+using namespace vw;
+using namespace vw::stereo;
+
+namespace vw {
+  template<> struct PixelFormatID<Vector3>   { static const PixelFormatEnum value = VW_PIXEL_GENERIC_3_CHANNEL; };
+}
+
+template <int istretch>
+class SubPixelCorrelateTest : public ::testing::Test {
+  const int IMAGE_SIZE, HALF_IMAGE_SIZE;
+
+public:
+  SubPixelCorrelateTest() : IMAGE_SIZE(100), HALF_IMAGE_SIZE(50) {}
+
+protected:
+  typedef LogStereoPreprocessingFilter PreFilter;
+
+  void SetUp() {
+    stretch = float(istretch)/100;
+
+    boost::rand48 gen(10);
+    image1 = transform(channel_cast_rescale<uint8>(uniform_noise_view( gen, IMAGE_SIZE, IMAGE_SIZE )),
+                       AffineTransform(Matrix2x2(3,0,0,3),Vector2()),
+                       ZeroEdgeExtension(), BicubicInterpolation());
+    translation = HALF_IMAGE_SIZE-HALF_IMAGE_SIZE*stretch;
+    image2 = transform(image1, AffineTransform(Matrix2x2(stretch,0,0,1),
+                                               Vector2(translation,0) ),
+                       ZeroEdgeExtension(), BicubicInterpolation());
+
+    starting_disp.set_size(IMAGE_SIZE,IMAGE_SIZE);
+    for ( int i = 0; i < IMAGE_SIZE ; i++ ) {
+      int disparity = stretch * i + translation - i;
+      for ( int j = 0; j < IMAGE_SIZE; j++ )
+        starting_disp(i,j) = disparity;
+    }
+  }
+
+  template <class ViewT>
+  double check_error( ImageViewBase<ViewT> const& input ) {
+    ViewT const& disparity = input.impl();
+    double error = 0;
+    for ( int i = 0; i < IMAGE_SIZE; i++ ) {
+      float expected = stretch * float(i) + translation - i;
+      for ( int j = 0; j < IMAGE_SIZE; j++ )
+        error += disparity(i,j)[1] + fabs(disparity(i,j)[0] - expected);
+    }
+    return error / (double(IMAGE_SIZE)*double(IMAGE_SIZE));
+  }
+
+  float stretch, translation;
+  ImageView<uint8> image1, image2;
+  ImageView<PixelMask<Vector2f> > starting_disp;
+};
+
+typedef SubPixelCorrelateTest<95> SubPixelCorrelate95Test;
+typedef SubPixelCorrelateTest<90> SubPixelCorrelate90Test;
+typedef SubPixelCorrelateTest<80> SubPixelCorrelate80Test;
+typedef SubPixelCorrelateTest<70> SubPixelCorrelate70Test;
+
+// Testing Parabola SubPixel
+//--------------------------------------------------------------
+TEST_F( SubPixelCorrelate95Test, Parabola95 ) {
+  typedef SubpixelView<PreFilter, ImageView<uint8> > SubView;
+  ImageView<PixelMask<Vector2f> > disparity_map =
+    SubView( starting_disp, image1, image2,
+             7, 7, true, true, 1,
+             PreFilter(1.4), false );
+  double error = check_error( disparity_map );
+  EXPECT_LT(error, 0.336);
+}
+
+TEST_F( SubPixelCorrelate90Test, Parabola90 ) {
+  typedef SubpixelView<PreFilter, ImageView<uint8> > SubView;
+  ImageView<PixelMask<Vector2f> > disparity_map =
+    SubView( starting_disp, image1, image2,
+             7, 7, true, true, 1,
+             PreFilter(1.4), false );
+  double error = check_error( disparity_map );
+  EXPECT_LT(error, 0.379);
+}
+
+TEST_F( SubPixelCorrelate80Test, Parabola80 ) {
+  typedef SubpixelView<PreFilter, ImageView<uint8> > SubView;
+  ImageView<PixelMask<Vector2f> > disparity_map =
+    SubView( starting_disp, image1, image2,
+             7, 7, true, true, 1,
+             PreFilter(1.4), false );
+  double error = check_error( disparity_map );
+  EXPECT_LT(error, 0.310);
+}
+
+TEST_F( SubPixelCorrelate70Test, Parabola70 ) {
+  typedef SubpixelView<PreFilter, ImageView<uint8> > SubView;
+  ImageView<PixelMask<Vector2f> > disparity_map =
+    SubView( starting_disp, image1, image2,
+             7, 7, true, true, 1,
+             PreFilter(1.4), false );
+  double error = check_error( disparity_map );
+  EXPECT_LT(error, 0.427);
+}
+
+// Testing Bayes EM SubPixel
+//--------------------------------------------------------------
+TEST_F( SubPixelCorrelate95Test, BayesEM95 ) {
+  typedef SubpixelView<PreFilter, ImageView<float> > SubView;
+  ImageView<PixelMask<Vector2f> > disparity_map =
+    SubView( starting_disp,
+             channel_cast_rescale<float>(image1),
+             channel_cast_rescale<float>(image2),
+             7, 7, true, true, 2,
+             PreFilter(1.4), false );
+  double error = check_error( disparity_map );
+  EXPECT_LT(error, 0.056);
+}
+
+TEST_F( SubPixelCorrelate90Test, BayesEM90 ) {
+  typedef SubpixelView<PreFilter, ImageView<float> > SubView;
+  ImageView<PixelMask<Vector2f> > disparity_map =
+    SubView( starting_disp,
+             channel_cast_rescale<float>(image1),
+             channel_cast_rescale<float>(image2),
+             7, 7, true, true, 2,
+             PreFilter(1.4), false );
+  double error = check_error( disparity_map );
+  EXPECT_LT(error, 0.127);
+}
+
+TEST_F( SubPixelCorrelate80Test, BayesEM80 ) {
+  typedef SubpixelView<PreFilter, ImageView<float> > SubView;
+  ImageView<PixelMask<Vector2f> > disparity_map =
+    SubView( starting_disp,
+             channel_cast_rescale<float>(image1),
+             channel_cast_rescale<float>(image2),
+             7, 7, true, true, 2,
+             PreFilter(1.4), false );
+  double error = check_error( disparity_map );
+  EXPECT_LT(error, 0.362);
+}
+
+TEST_F( SubPixelCorrelate70Test, BayesEM70 ) {
+  typedef SubpixelView<PreFilter, ImageView<float> > SubView;
+  ImageView<PixelMask<Vector2f> > disparity_map =
+    SubView( starting_disp,
+             channel_cast_rescale<float>(image1),
+             channel_cast_rescale<float>(image2),
+             7, 7, true, true, 2,
+             PreFilter(1.4), false );
+  double error = check_error( disparity_map );
+  EXPECT_LT(error, 0.748);
+}