Planar tracker polish.

- Fixes the correlation checking code that was broken in the
  previous commit. The bug was a transpose error.
- Fixes a memory leak of the warp functor, found by Sameer.
- Various cleanups done at Sameer's suggestion.

Thanks to Sameer Agarwal for a code review.
This commit is contained in:
Keir Mierle
2012-06-09 06:55:21 +00:00
parent 5728b11ef2
commit f9be7fca17
3 changed files with 61 additions and 62 deletions

View File

@@ -34,25 +34,22 @@ inline T SampleNearest(const Array3D<T> &image,
return image(i, j, v);
}
static inline void LinearInitAxis(float fx, int width,
int *x1, int *x2,
float *dx1, float *dx2) {
const int ix = static_cast<int>(fx);
inline void LinearInitAxis(float x, int size,
int *x1, int *x2,
float *dx) {
const int ix = static_cast<int>(x);
if (ix < 0) {
*x1 = 0;
*x2 = 0;
*dx1 = 1;
*dx2 = 0;
} else if (ix > width - 2) {
*x1 = width - 1;
*x2 = width - 1;
*dx1 = 1;
*dx2 = 0;
*dx = 1.0;
} else if (ix > size - 2) {
*x1 = size - 1;
*x2 = size - 1;
*dx = 1.0;
} else {
*x1 = ix;
*x2 = *x1 + 1;
*dx1 = *x2 - fx;
*dx2 = 1 - *dx1;
*x2 = ix + 1;
*dx = *x2 - x;
}
}
@@ -60,18 +57,18 @@ static inline void LinearInitAxis(float fx, int width,
template<typename T>
inline T SampleLinear(const Array3D<T> &image, float y, float x, int v = 0) {
int x1, y1, x2, y2;
float dx1, dy1, dx2, dy2;
float dx, dy;
LinearInitAxis(y, image.Height(), &y1, &y2, &dy1, &dy2);
LinearInitAxis(x, image.Width(), &x1, &x2, &dx1, &dx2);
LinearInitAxis(y, image.Height(), &y1, &y2, &dy);
LinearInitAxis(x, image.Width(), &x1, &x2, &dx);
const T im11 = image(y1, x1, v);
const T im12 = image(y1, x2, v);
const T im21 = image(y2, x1, v);
const T im22 = image(y2, x2, v);
return T(dy1 * ( dx1 * im11 + dx2 * im12 ) +
dy2 * ( dx1 * im21 + dx2 * im22 ));
return T( dy * ( dx * im11 + (1.0 - dx) * im12 ) +
(1 - dy) * ( dx * im21 + (1.0 - dx) * im22 ));
}
/// Linear interpolation, of all channels. The sample is assumed to have the
@@ -79,10 +76,10 @@ inline T SampleLinear(const Array3D<T> &image, float y, float x, int v = 0) {
template<typename T>
inline void SampleLinear(const Array3D<T> &image, float y, float x, T *sample) {
int x1, y1, x2, y2;
float dx1, dy1, dx2, dy2;
float dx, dy;
LinearInitAxis(y, image.Height(), &y1, &y2, &dy1, &dy2);
LinearInitAxis(x, image.Width(), &x1, &x2, &dx1, &dx2);
LinearInitAxis(y, image.Height(), &y1, &y2, &dy);
LinearInitAxis(x, image.Width(), &x1, &x2, &dx);
for (int i = 0; i < image.Depth(); ++i) {
const T im11 = image(y1, x1, i);
@@ -90,8 +87,8 @@ inline void SampleLinear(const Array3D<T> &image, float y, float x, T *sample) {
const T im21 = image(y2, x1, i);
const T im22 = image(y2, x2, i);
sample[i] = T(dy1 * ( dx1 * im11 + dx2 * im12 ) +
dy2 * ( dx1 * im21 + dx2 * im22 ));
sample[i] = T( dy * ( dx * im11 + (1.0 - dx) * im12 ) +
(1 - dy) * ( dx * im21 + (1.0 - dx) * im22 ));
}
}

View File

@@ -81,9 +81,9 @@ bool AllInBounds(const FloatImage &image,
return true;
}
// The "AutoDiff::Sample()" function allows sampling an image at an x, y
// position such that if x and y are jets, then the derivative information is
// correctly propagated.
// Sample the image at position (x, y) but use the gradient, if present, to
// propagate derivatives from x and y. This is needed to integrate the numeric
// image gradients with Ceres's autodiff framework.
template<typename T>
static T SampleWithDerivative(const FloatImage &image_and_gradient,
const T &x,
@@ -172,7 +172,7 @@ class WarpCostFunctor {
// Sample the pattern and gradients.
SampleLinear(image_and_gradient1_,
image_position(1), // Sample is r, c.
image_position(1), // SampleLinear is r, c.
image_position(0),
&pattern_and_gradient_(r, c, 0));
@@ -180,7 +180,7 @@ class WarpCostFunctor {
double mask_value = 1.0;
if (options_.image1_mask != NULL) {
SampleLinear(*options_.image1_mask,
image_position(1),
image_position(1), // SampleLinear is r, c.
image_position(0),
&pattern_mask_(r, c, 0));
mask_value = pattern_mask_(r, c);
@@ -216,6 +216,16 @@ class WarpCostFunctor {
// Sample the mask early; if it's zero, this pixel has no effect. This
// allows early bailout from the expensive sampling that happens below.
//
// Note that partial masks are not short circuited. To see why short
// circuiting produces bitwise-exact same results, consider that the
// residual for each pixel is
//
// residual = mask * (src - dst) ,
//
// and for jets, multiplying by a scalar multiplies the derivative
// components by the scalar as well. Therefore, if the mask is exactly
// zero, then so too will the final residual and derivatives.
double mask_value = 1.0;
if (options_.image1_mask != NULL) {
mask_value = pattern_mask_(r, c);
@@ -240,7 +250,7 @@ class WarpCostFunctor {
// Sample the source. This is made complicated by ESM mode.
T src_sample;
if (0 && options_.use_esm && !JetOps<T>::IsScalar()) {
if (options_.use_esm && !JetOps<T>::IsScalar()) {
// In ESM mode, the derivative of the source is also taken into
// account. This changes the linearization in a way that causes
// better convergence. Copy the derivative of the warp parameters
@@ -270,8 +280,6 @@ class WarpCostFunctor {
src_sample = T(pattern_and_gradient_(r, c));
}
//LG << "src_sample: " << src_sample;
// Normalize the samples by the mean values of each signal. The typical
// light model assumes multiplicative intensity changes with changing
// light, so this is a reasonable choice. Note that dst_mean has
@@ -281,8 +289,6 @@ class WarpCostFunctor {
dst_sample /= dst_mean;
}
//LG << "dst_sample: " << dst_sample;
// The difference is the error.
T error = src_sample - dst_sample;
@@ -389,8 +395,8 @@ class WarpCostFunctor {
double x = pattern_and_gradient_(r, c);
double y = SampleLinear(image_and_gradient2_,
image2_position[0],
image2_position[1]);
image2_position[1], // SampleLinear is r, c.
image2_position[0]);
// Weight the signals by the mask, if one is present.
if (options_.image1_mask != NULL) {
@@ -1111,13 +1117,14 @@ void TemplatedTrackRegion(const FloatImage &image1,
x1, y1, x2, y2);
for (int i = 0; i < 4; ++i) {
LG << "P" << i << ": (" << x1[i] << ", " << y1[i] << "); brute ("
<< x2[i] << ", " << y2[i] << "); (dx, dy): (" << (x2[i] - x1[i]) << ", "
<< (y2[i] - y1[i]) << ").";
<< x2[i] << ", " << y2[i] << "); (dx, dy): (" << (x2[i] - x1[i])
<< ", " << (y2[i] - y1[i]) << ").";
}
}
// Prepare the initial warp parameters from the four correspondences.
// Note: This must happen after the brute initialization runs.
// Note: This must happen after the brute initialization runs, since the
// brute initialization mutates x2 and y2 in place.
Warp warp(x1, y1, x2, y2);
// Decide how many samples to use in the x and y dimensions.
@@ -1125,22 +1132,6 @@ void TemplatedTrackRegion(const FloatImage &image1,
int num_samples_y;
PickSampling(x1, y1, x2, y2, &num_samples_x, &num_samples_y);
ceres::Solver::Options solver_options;
solver_options.linear_solver_type = ceres::DENSE_QR;
solver_options.max_num_iterations = options.max_iterations;
solver_options.update_state_every_iteration = true;
solver_options.parameter_tolerance = 1e-16;
solver_options.function_tolerance = 1e-16;
// TODO(keir): Consider removing these options before committing.
solver_options.numeric_derivative_relative_step_size = 1e-3;
solver_options.check_gradients = false;
solver_options.gradient_check_relative_precision = 1e-10;
solver_options.minimizer_progress_to_stdout = false;
// Prevent the corners from going outside the destination image.
BoundaryCheckingCallback<Warp> callback(image2, warp, x1, y1);
solver_options.callbacks.push_back(&callback);
// Compute the warp from rectangular coordinates.
Mat3 canonical_homography = ComputeCanonicalHomography(x1, y1,
@@ -1158,9 +1149,7 @@ void TemplatedTrackRegion(const FloatImage &image1,
warp);
// Construct the problem with a single residual.
ceres::Problem::Options problem_options;
problem_options.cost_function_ownership = ceres::DO_NOT_TAKE_OWNERSHIP;
ceres::Problem problem(problem_options);
ceres::Problem problem;
problem.AddResidualBlock(
new ceres::AutoDiffCostFunction<
WarpCostFunctor<Warp>,
@@ -1170,6 +1159,19 @@ void TemplatedTrackRegion(const FloatImage &image1,
NULL,
warp.parameters);
// Configure the solve.
ceres::Solver::Options solver_options;
solver_options.linear_solver_type = ceres::DENSE_QR;
solver_options.max_num_iterations = options.max_iterations;
solver_options.update_state_every_iteration = true;
solver_options.parameter_tolerance = 1e-16;
solver_options.function_tolerance = 1e-16;
// Prevent the corners from going outside the destination image.
BoundaryCheckingCallback<Warp> callback(image2, warp, x1, y1);
solver_options.callbacks.push_back(&callback);
// Run the solve.
ceres::Solver::Summary summary;
ceres::Solve(solver_options, &problem, &summary);

View File

@@ -114,10 +114,10 @@ void TrackRegion(const FloatImage &image1,
TrackRegionResult *result);
// Sample a "canonical" version of the passed planar patch, using bilinear
// sampling. The passed corners must be within the image, possibly with a small
// amount of slop, perhaps 2 pixels, around the edges (so e.g. a corner of the
// patch cannot lie directly on the edge of the image). Four corners are always
// required. All channels are interpolated.
// sampling. The passed corners must be within the image, and have at least two
// pixels of border around them. (so e.g. a corner of the patch cannot lie
// directly on the edge of the image). Four corners are always required. All
// channels are interpolated.
bool SamplePlanarPatch(const FloatImage &image,
const double *xs, const double *ys,
int num_samples_x, int num_samples_y,