utest.cpp
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3 #include <gtest/gtest.h>
4 
10 
11 class PinholeTest : public testing::Test
12 {
13 protected:
14  virtual void SetUp()
15  {
17  // These parameters taken from a real camera calibration
18  double D[] = {-0.363528858080088, 0.16117037733986861, -8.1109585007538829e-05, -0.00044776712298447841, 0.0};
19  double K[] = {430.15433020105519, 0.0, 311.71339830549732,
20  0.0, 430.60920415473657, 221.06824942698509,
21  0.0, 0.0, 1.0};
22  double R[] = {0.99806560714807102, 0.0068562422224214027, 0.061790256276695904,
23  -0.0067522959054715113, 0.99997541519165112, -0.0018909025066874664,
24  -0.061801701660692349, 0.0014700186639396652, 0.99808736527268516};
25  double P[] = {295.53402059708782, 0.0, 285.55760765075684, 0.0,
26  0.0, 295.53402059708782, 223.29617881774902, 0.0,
27  0.0, 0.0, 1.0, 0.0};
28 
29  cam_info_.header.frame_id = "tf_frame";
30  cam_info_.height = 480;
31  cam_info_.width = 640;
32  // No ROI
33  cam_info_.D.resize(5);
34  std::copy(D, D+5, cam_info_.D.begin());
35  std::copy(K, K+9, cam_info_.K.begin());
36  std::copy(R, R+9, cam_info_.R.begin());
37  std::copy(P, P+12, cam_info_.P.begin());
39 
41  }
42 
43  sensor_msgs::CameraInfo cam_info_;
45 };
46 
47 TEST_F(PinholeTest, accessorsCorrect)
48 {
49  EXPECT_STREQ("tf_frame", model_.tfFrame().c_str());
50  EXPECT_EQ(cam_info_.P[0], model_.fx());
51  EXPECT_EQ(cam_info_.P[5], model_.fy());
52  EXPECT_EQ(cam_info_.P[2], model_.cx());
53  EXPECT_EQ(cam_info_.P[6], model_.cy());
54 }
55 
56 TEST_F(PinholeTest, projectPoint)
57 {
58  // Spot test an arbitrary point.
59  {
60  cv::Point2d uv(100, 100);
61  cv::Point3d xyz = model_.projectPixelTo3dRay(uv);
62  EXPECT_NEAR(-0.62787224048135637, xyz.x, 1e-8);
63  EXPECT_NEAR(-0.41719792045817677, xyz.y, 1e-8);
64  EXPECT_DOUBLE_EQ(1.0, xyz.z);
65  }
66 
67  // Principal point should project straight out.
68  {
69  cv::Point2d uv(model_.cx(), model_.cy());
70  cv::Point3d xyz = model_.projectPixelTo3dRay(uv);
71  EXPECT_DOUBLE_EQ(0.0, xyz.x);
72  EXPECT_DOUBLE_EQ(0.0, xyz.y);
73  EXPECT_DOUBLE_EQ(1.0, xyz.z);
74  }
75 
76  // Check projecting to 3d and back over entire image is accurate.
77  const size_t step = 10;
78  for (size_t row = 0; row <= cam_info_.height; row += step) {
79  for (size_t col = 0; col <= cam_info_.width; col += step) {
80  cv::Point2d uv(row, col), uv_back;
81  cv::Point3d xyz = model_.projectPixelTo3dRay(uv);
82  uv_back = model_.project3dToPixel(xyz);
83  // Measured max error at 1.13687e-13
84  EXPECT_NEAR(uv.x, uv_back.x, 1.14e-13) << "at (" << row << ", " << col << ")";
85  EXPECT_NEAR(uv.y, uv_back.y, 1.14e-13) << "at (" << row << ", " << col << ")";
86  }
87  }
88 }
89 
90 TEST_F(PinholeTest, rectifyPoint)
91 {
92  // Spot test an arbitrary point.
93  {
94  cv::Point2d uv_raw(100, 100), uv_rect;
95  uv_rect = model_.rectifyPoint(uv_raw);
96  EXPECT_DOUBLE_EQ(142.30311584472656, uv_rect.x);
97  EXPECT_DOUBLE_EQ(132.061065673828, uv_rect.y);
98  }
99 
101 #if 0
102  // Test rectifyPoint takes (c'x, c'y) [from K] -> (cx, cy) [from P].
103  double cxp = model_.intrinsicMatrix()(0,2), cyp = model_.intrinsicMatrix()(1,2);
104  {
105  cv::Point2d uv_raw(cxp, cyp), uv_rect;
106  model_.rectifyPoint(uv_raw, uv_rect);
107  EXPECT_NEAR(uv_rect.x, model_.cx(), 1e-4);
108  EXPECT_NEAR(uv_rect.y, model_.cy(), 1e-4);
109  }
110 
111  // Test unrectifyPoint takes (cx, cy) [from P] -> (c'x, c'y) [from K].
112  {
113  cv::Point2d uv_rect(model_.cx(), model_.cy()), uv_raw;
114  model_.unrectifyPoint(uv_rect, uv_raw);
115  EXPECT_NEAR(uv_raw.x, cxp, 1e-4);
116  EXPECT_NEAR(uv_raw.y, cyp, 1e-4);
117  }
118 #endif
119 
120  // Check rectifying then unrectifying over most of the image is accurate.
121  const size_t step = 5;
122  const size_t border = 65; // Expect bad accuracy far from the center of the image.
123  for (size_t row = border; row <= cam_info_.height - border; row += step) {
124  for (size_t col = border; col <= cam_info_.width - border; col += step) {
125  cv::Point2d uv_raw(row, col), uv_rect, uv_unrect;
126  uv_rect = model_.rectifyPoint(uv_raw);
127  uv_unrect = model_.unrectifyPoint(uv_rect);
128  // Check that we're at least within a pixel...
129  EXPECT_NEAR(uv_raw.x, uv_unrect.x, 1.0);
130  EXPECT_NEAR(uv_raw.y, uv_unrect.y, 1.0);
131  }
132  }
133 }
134 
135 TEST_F(PinholeTest, getDeltas)
136 {
137  double u = 100.0, v = 200.0, du = 17.0, dv = 23.0, Z = 2.0;
138  cv::Point2d uv0(u, v), uv1(u + du, v + dv);
139  cv::Point3d xyz0, xyz1;
140  xyz0 = model_.projectPixelTo3dRay(uv0);
141  xyz0 *= (Z / xyz0.z);
142  xyz1 = model_.projectPixelTo3dRay(uv1);
143  xyz1 *= (Z / xyz1.z);
144 
145  EXPECT_NEAR(model_.getDeltaU(xyz1.x - xyz0.x, Z), du, 1e-4);
146  EXPECT_NEAR(model_.getDeltaV(xyz1.y - xyz0.y, Z), dv, 1e-4);
147  EXPECT_NEAR(model_.getDeltaX(du, Z), xyz1.x - xyz0.x, 1e-4);
148  EXPECT_NEAR(model_.getDeltaY(dv, Z), xyz1.y - xyz0.y, 1e-4);
149 }
150 
151 TEST_F(PinholeTest, initialization)
152 {
153 
154  sensor_msgs::CameraInfo info;
156 
157  camera.fromCameraInfo(info);
158 
159  EXPECT_EQ(camera.initialized(), 1);
160  EXPECT_EQ(camera.projectionMatrix().rows, 3);
161  EXPECT_EQ(camera.projectionMatrix().cols, 4);
162 }
163 
164 TEST_F(PinholeTest, rectifyIfCalibrated)
165 {
167  // Ideally this test would have two images stored on disk
168  // one which is distorted and the other which is rectified,
169  // and then rectification would take place here and the output
170  // image compared to the one on disk (which would mean if
171  // the distortion coefficients above can't change once paired with
172  // an image).
173 
174  // Later could incorporate distort code
175  // (https://github.com/lucasw/vimjay/blob/master/src/standalone/distort_image.cpp)
176  // to take any image distort it, then undistort with rectifyImage,
177  // and given the distortion coefficients are consistent the input image
178  // and final output image should be mostly the same (though some
179  // interpolation error
180  // creeps in), except for outside a masked region where information was lost.
181  // The masked region can be generated with a pure white image that
182  // goes through the same process (if it comes out completely black
183  // then the distortion parameters are problematic).
184 
185  // For now generate an image and pass the test simply if
186  // the rectified image does not match the distorted image.
187  // Then zero out the first distortion coefficient and run
188  // the test again.
189  // Then zero out all the distortion coefficients and test
190  // that the output image is the same as the input.
191  cv::Mat distorted_image(cv::Size(cam_info_.width, cam_info_.height), CV_8UC3, cv::Scalar(0, 0, 0));
192 
193  // draw a grid
194  const cv::Scalar color = cv::Scalar(255, 255, 255);
195  // draw the lines thick so the proportion of error due to
196  // interpolation is reduced
197  const int thickness = 7;
198  const int type = 8;
199  for (size_t y = 0; y <= cam_info_.height; y += cam_info_.height/10)
200  {
201  cv::line(distorted_image,
202  cv::Point(0, y), cv::Point(cam_info_.width, y),
203  color, type, thickness);
204  }
205  for (size_t x = 0; x <= cam_info_.width; x += cam_info_.width/10)
206  {
207  // draw the lines thick so the prorportion of interpolation error is reduced
208  cv::line(distorted_image,
209  cv::Point(x, 0), cv::Point(x, cam_info_.height),
210  color, type, thickness);
211  }
212 
213  cv::Mat rectified_image;
214  // Just making this number up, maybe ought to be larger
215  // since a completely different image would be on the order of
216  // width * height * 255 = 78e6
217  const double diff_threshold = 10000.0;
218  double error;
219 
220  // Test that rectified image is sufficiently different
221  // using default distortion
222  model_.rectifyImage(distorted_image, rectified_image);
223  error = cv::norm(distorted_image, rectified_image, cv::NORM_L1);
224  // Just making this number up, maybe ought to be larger
225  EXPECT_GT(error, diff_threshold);
226 
227  // Test that rectified image is sufficiently different
228  // using default distortion but with first element zeroed
229  // out.
230  sensor_msgs::CameraInfo cam_info_2 = cam_info_;
231  cam_info_2.D[0] = 0.0;
232  model_.fromCameraInfo(cam_info_2);
233  model_.rectifyImage(distorted_image, rectified_image);
234  error = cv::norm(distorted_image, rectified_image, cv::NORM_L1);
235  EXPECT_GT(error, diff_threshold);
236 
237  // Test that rectified image is the same using zero distortion
238  cam_info_2.D.assign(cam_info_2.D.size(), 0);
239  model_.fromCameraInfo(cam_info_2);
240  model_.rectifyImage(distorted_image, rectified_image);
241  error = cv::norm(distorted_image, rectified_image, cv::NORM_L1);
242  EXPECT_EQ(error, 0);
243 
244  // Test that rectified image is the same using empty distortion
245  cam_info_2.D.clear();
246  model_.fromCameraInfo(cam_info_2);
247  model_.rectifyImage(distorted_image, rectified_image);
248  error = cv::norm(distorted_image, rectified_image, cv::NORM_L1);
249  EXPECT_EQ(error, 0);
250 
251  // restore original distortion
253 }
254 
255 int main(int argc, char** argv)
256 {
257  testing::InitGoogleTest(&argc, argv);
258  return RUN_ALL_TESTS();
259 }
const cv::Matx33d & intrinsicMatrix() const
Returns the original camera matrix.
bool initialized() const
Returns true if the camera has been initialized.
image_geometry::PinholeCameraModel model_
Definition: utest.cpp:44
cv::Point3d projectPixelTo3dRay(const cv::Point2d &uv_rect) const
Project a rectified pixel to a 3d ray.
double cx() const
Returns the x coordinate of the optical center.
virtual void SetUp()
Definition: utest.cpp:14
double getDeltaY(double deltaV, double Z) const
Compute delta Y, given Z in Cartesian space and delta v in pixels.
double cy() const
Returns the y coordinate of the optical center.
cv::Point2d unrectifyPoint(const cv::Point2d &uv_rect) const
Compute the raw image coordinates of a pixel in the rectified image.
std::string tfFrame() const
Get the name of the camera coordinate frame in tf.
void rectifyImage(const cv::Mat &raw, cv::Mat &rectified, int interpolation=cv::INTER_LINEAR) const
Rectify a raw camera image.
TEST_F(PinholeTest, accessorsCorrect)
Definition: utest.cpp:47
double getDeltaU(double deltaX, double Z) const
Compute delta u, given Z and delta X in Cartesian space.
bool fromCameraInfo(const sensor_msgs::CameraInfo &msg)
Set the camera parameters from the sensor_msgs/CameraInfo message.
int main(int argc, char **argv)
Definition: utest.cpp:255
double getDeltaX(double deltaU, double Z) const
Compute delta X, given Z in Cartesian space and delta u in pixels.
Simplifies interpreting images geometrically using the parameters from sensor_msgs/CameraInfo.
cv::Point2d rectifyPoint(const cv::Point2d &uv_raw) const
Compute the rectified image coordinates of a pixel in the raw image.
double fy() const
Returns the focal length (pixels) in y direction of the rectified image.
sensor_msgs::CameraInfo cam_info_
Definition: utest.cpp:43
double getDeltaV(double deltaY, double Z) const
Compute delta v, given Z and delta Y in Cartesian space.
const cv::Matx34d & projectionMatrix() const
Returns the projection matrix.
cv::Point2d project3dToPixel(const cv::Point3d &xyz) const
Project a 3d point to rectified pixel coordinates.
double fx() const
Returns the focal length (pixels) in x direction of the rectified image.


image_geometry
Author(s): Patrick Mihelich
autogenerated on Thu Jun 6 2019 19:58:02