opencv/modules/gpu/doc/camera_calibration_and_3d_reconstruction.rst
2011-03-03 07:29:55 +00:00

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Camera Calibration and 3d Reconstruction
========================================
.. highlight:: cpp
.. index:: gpu::StereoBM_GPU
.. _gpu::StereoBM_GPU:
gpu::StereoBM_GPU
-----------------
.. c:type:: gpu::StereoBM_GPU
The class for computing stereo correspondence using block matching algorithm. ::
class StereoBM_GPU
{
public:
enum { BASIC_PRESET = 0, PREFILTER_XSOBEL = 1 };
enum { DEFAULT_NDISP = 64, DEFAULT_WINSZ = 19 };
StereoBM_GPU();
StereoBM_GPU(int preset, int ndisparities = DEFAULT_NDISP,
int winSize = DEFAULT_WINSZ);
void operator() (const GpuMat& left, const GpuMat& right,
GpuMat& disparity);
void operator() (const GpuMat& left, const GpuMat& right,
GpuMat& disparity, const Stream & stream);
static bool checkIfGpuCallReasonable();
int preset;
int ndisp;
int winSize;
float avergeTexThreshold;
...
};
This class computes the disparity map using block matching algorithm. The class also performs pre- and post- filtering steps: sobel prefiltering (if PREFILTER_XSOBEL flag is set) and low textureness filtering (if averageTexThreshols
:math:`>` 0). If ``avergeTexThreshold = 0`` low textureness filtering is disabled, otherwise disparity is set to 0 in each point ``(x, y)`` where for left image
:math:`\sum HorizontalGradiensInWindow(x, y, winSize) < (winSize \cdot winSize) \cdot avergeTexThreshold` i.e. input left image is low textured.
.. index:: gpu::StereoBM_GPU::StereoBM_GPU
.. _gpu::StereoBM_GPU::StereoBM_GPU:
gpu::StereoBM_GPU::StereoBM_GPU
-----------------------------------_
.. c:function:: StereoBM_GPU::StereoBM_GPU()
.. c:function:: StereoBM_GPU::StereoBM_GPU(int preset, int ndisparities = DEFAULT_NDISP, int winSize = DEFAULT_WINSZ)
StereoBMGPU constructors.
:param preset: Preset:
* **BASIC_PRESET** Without preprocessing.
* **PREFILTER_XSOBEL** Sobel prefilter.
:param ndisparities: Number of disparities. Must be a multiple of 8 and less or equal then 256.
:param winSize: Block size.
.. index:: gpu::StereoBM_GPU::operator ()
.. _gpu::StereoBM_GPU::operator ():
gpu::StereoBM_GPU::operator ()
----------------------------------
.. c:function:: void StereoBM_GPU::operator() (const GpuMat\& left, const GpuMat\& right, GpuMat\& disparity)
.. c:function:: void StereoBM_GPU::operator() (const GpuMat\& left, const GpuMat\& right, GpuMat\& disparity, const Stream\& stream)
The stereo correspondence operator. Finds the disparity for the specified rectified stereo pair.
:param left: Left image; supports only ``CV_8UC1`` type.
:param right: Right image with the same size and the same type as the left one.
:param disparity: Output disparity map. It will be ``CV_8UC1`` image with the same size as the input images.
:param stream: Stream for the asynchronous version.
.. index:: gpu::StereoBM_GPU::checkIfGpuCallReasonable
.. _gpu::StereoBM_GPU::checkIfGpuCallReasonable:
gpu::StereoBM_GPU::checkIfGpuCallReasonable
-----------------------------------------------
.. c:function:: bool StereoBM_GPU::checkIfGpuCallReasonable()
Some heuristics that tries to estmate if the current GPU will be faster then CPU in this algorithm. It queries current active device.
.. index:: gpu::StereoBeliefPropagation
.. _gpu::StereoBeliefPropagation:
gpu::StereoBeliefPropagation
----------------------------
.. c:type:: gpu::StereoBeliefPropagation
The class for computing stereo correspondence using belief propagation algorithm. ::
class StereoBeliefPropagation
{
public:
enum { DEFAULT_NDISP = 64 };
enum { DEFAULT_ITERS = 5 };
enum { DEFAULT_LEVELS = 5 };
static void estimateRecommendedParams(int width, int height,
int& ndisp, int& iters, int& levels);
explicit StereoBeliefPropagation(int ndisp = DEFAULT_NDISP,
int iters = DEFAULT_ITERS,
int levels = DEFAULT_LEVELS,
int msg_type = CV_32F);
StereoBeliefPropagation(int ndisp, int iters, int levels,
float max_data_term, float data_weight,
float max_disc_term, float disc_single_jump,
int msg_type = CV_32F);
void operator()(const GpuMat& left, const GpuMat& right,
GpuMat& disparity);
void operator()(const GpuMat& left, const GpuMat& right,
GpuMat& disparity, Stream& stream);
void operator()(const GpuMat& data, GpuMat& disparity);
void operator()(const GpuMat& data, GpuMat& disparity, Stream& stream);
int ndisp;
int iters;
int levels;
float max_data_term;
float data_weight;
float max_disc_term;
float disc_single_jump;
int msg_type;
...
};
The class implements Pedro F. Felzenszwalb algorithm
felzenszwalb_bp
. It can compute own data cost (using truncated linear model) or use user-provided data cost.
**Please note:** ``StereoBeliefPropagation`` requires a lot of memory:
.. math::
width \_ step \cdot height \cdot ndisp \cdot 4 \cdot (1 + 0.25)
for message storage and
.. math::
width \_ step \cdot height \cdot ndisp \cdot (1 + 0.25 + 0.0625 + \dotsm + \frac{1}{4^{levels}}
for data cost storage. ``width_step`` is the number of bytes in a line including the padding.
.. index:: gpu::StereoBeliefPropagation::StereoBeliefPropagation
gpu::StereoBeliefPropagation::StereoBeliefPropagation
---------------------------------------------------------
.. c:function:: StereoBeliefPropagation::StereoBeliefPropagation( int ndisp = DEFAULT_NDISP, int iters = DEFAULT_ITERS, int levels = DEFAULT_LEVELS, int msg_type = CV_32F)
.. c:function:: StereoBeliefPropagation::StereoBeliefPropagation( int ndisp, int iters, int levels, float max_data_term, float data_weight, float max_disc_term, float disc_single_jump, int msg_type = CV_32F)
StereoBeliefPropagation constructors.
:param ndisp: Number of disparities.
:param iters: Number of BP iterations on each level.
:param levels: Number of levels.
:param max_data_term: Threshold for data cost truncation.
:param data_weight: Data weight.
:param max_disc_term: Threshold for discontinuity truncation.
:param disc_single_jump: Discontinuity single jump.
:param msg_type: Type for messages. Supports ``CV_16SC1`` and ``CV_32FC1``.
``StereoBeliefPropagation`` uses truncated linear model for the data cost and discontinuity term:
.. math::
DataCost = data \_ weight \cdot \min ( \lvert I_2-I_1 \rvert , max \_ data \_ term)
.. math::
DiscTerm = \min (disc \_ single \_ jump \cdot \lvert f_1-f_2 \rvert , max \_ disc \_ term)
For more details please see
felzenszwalb_bp
.
By default ``StereoBeliefPropagation`` uses floating-point arithmetics and ``CV_32FC1`` type for messages. But also it can use fixed-point arithmetics and ``CV_16SC1`` type for messages for better perfomance. To avoid overflow in this case, the parameters must satisfy
.. math::
10 \cdot 2^{levels-1} \cdot max \_ data \_ term < SHRT \_ MAX
.. index:: gpu::StereoBeliefPropagation::estimateRecommendedParams
gpu::StereoBeliefPropagation::estimateRecommendedParams
-----------------------------------------------------------
.. c:function:: void StereoBeliefPropagation::estimateRecommendedParams( int width, int height, int\& ndisp, int\& iters, int\& levels)
Some heuristics that tries to compute recommended parameters (ndisp, itersand levels) for specified image size (widthand height).
.. index:: gpu::StereoBeliefPropagation::operator ()
gpu::StereoBeliefPropagation::operator ()
---------------------------------------------
.. c:function:: void StereoBeliefPropagation::operator()( const GpuMat\& left, const GpuMat\& right, GpuMat\& disparity)
.. c:function:: void StereoBeliefPropagation::operator()( const GpuMat\& left, const GpuMat\& right, GpuMat\& disparity, Stream\& stream)
The stereo correspondence operator. Finds the disparity for the specified rectified stereo pair or data cost.
:param left: Left image; supports ``CV_8UC1`` , ``CV_8UC3`` and ``CV_8UC4`` types.
:param right: Right image with the same size and the same type as the left one.
:param disparity: Output disparity map. If ``disparity`` is empty output type will be ``CV_16SC1`` , otherwise output type will be ``disparity.type()`` .
:param stream: Stream for the asynchronous version.
.. c:function:: void StereoBeliefPropagation::operator()( const GpuMat\& data, GpuMat\& disparity)
.. c:function:: void StereoBeliefPropagation::operator()( const GpuMat\& data, GpuMat\& disparity, Stream\& stream)
* **data** The user specified data cost. It must have ``msg_type`` type and :math:`\texttt{imgRows} \cdot \texttt{ndisp} \times \texttt{imgCols}` size.
* **disparity** Output disparity map. If ``disparity`` is empty output type will be ``CV_16SC1`` , otherwise output type will be ``disparity.type()`` .
* **stream** Stream for the asynchronous version.
.. index:: gpu::StereoConstantSpaceBP
.. _gpu::StereoConstantSpaceBP:
gpu::StereoConstantSpaceBP
--------------------------
.. c:type:: gpu::StereoConstantSpaceBP
The class for computing stereo correspondence using constant space belief propagation algorithm. ::
class StereoConstantSpaceBP
{
public:
enum { DEFAULT_NDISP = 128 };
enum { DEFAULT_ITERS = 8 };
enum { DEFAULT_LEVELS = 4 };
enum { DEFAULT_NR_PLANE = 4 };
static void estimateRecommendedParams(int width, int height,
int& ndisp, int& iters, int& levels, int& nr_plane);
explicit StereoConstantSpaceBP(int ndisp = DEFAULT_NDISP,
int iters = DEFAULT_ITERS,
int levels = DEFAULT_LEVELS,
int nr_plane = DEFAULT_NR_PLANE,
int msg_type = CV_32F);
StereoConstantSpaceBP(int ndisp, int iters, int levels, int nr_plane,
float max_data_term, float data_weight,
float max_disc_term, float disc_single_jump,
int min_disp_th = 0,
int msg_type = CV_32F);
void operator()(const GpuMat& left, const GpuMat& right,
GpuMat& disparity);
void operator()(const GpuMat& left, const GpuMat& right,
GpuMat& disparity, Stream& stream);
int ndisp;
int iters;
int levels;
int nr_plane;
float max_data_term;
float data_weight;
float max_disc_term;
float disc_single_jump;
int min_disp_th;
int msg_type;
bool use_local_init_data_cost;
...
};
The class implements Q. Yang algorithm
qx_csbp
. ``StereoConstantSpaceBP`` supports both local minimum and global minimum data cost initialization algortihms. For more details please see the paper. By default local algorithm is used, and to enable global algorithm set ``use_local_init_data_cost`` to false.
.. index:: gpu::StereoConstantSpaceBP::StereoConstantSpaceBP
gpu::StereoConstantSpaceBP::StereoConstantSpaceBP
-----------------------------------------------------
.. c:function:: StereoConstantSpaceBP::StereoConstantSpaceBP(int ndisp = DEFAULT_NDISP, int iters = DEFAULT_ITERS, int levels = DEFAULT_LEVELS, int nr_plane = DEFAULT_NR_PLANE, int msg_type = CV_32F)
.. c:function:: StereoConstantSpaceBP::StereoConstantSpaceBP(int ndisp, int iters, int levels, int nr_plane, float max_data_term, float data_weight, float max_disc_term, float disc_single_jump, int min_disp_th = 0, int msg_type = CV_32F)
StereoConstantSpaceBP constructors.
:param ndisp: Number of disparities.
:param iters: Number of BP iterations on each level.
:param levels: Number of levels.
:param nr_plane: Number of disparity levels on the first level
:param max_data_term: Truncation of data cost.
:param data_weight: Data weight.
:param max_disc_term: Truncation of discontinuity.
:param disc_single_jump: Discontinuity single jump.
:param min_disp_th: Minimal disparity threshold.
:param msg_type: Type for messages. Supports ``CV_16SC1`` and ``CV_32FC1`` .
``StereoConstantSpaceBP`` uses truncated linear model for the data cost and discontinuity term:
.. math::
DataCost = data \_ weight \cdot \min ( \lvert I_2-I_1 \rvert , max \_ data \_ term)
.. math::
DiscTerm = \min (disc \_ single \_ jump \cdot \lvert f_1-f_2 \rvert , max \_ disc \_ term)
For more details please see
qx_csbp
.
By default ``StereoConstantSpaceBP`` uses floating-point arithmetics and ``CV_32FC1`` type for messages. But also it can use fixed-point arithmetics and ``CV_16SC1`` type for messages for better perfomance. To avoid overflow in this case, the parameters must satisfy
.. math::
10 \cdot 2^{levels-1} \cdot max \_ data \_ term < SHRT \_ MAX
.. index:: gpu::StereoConstantSpaceBP::estimateRecommendedParams
gpu::StereoConstantSpaceBP::estimateRecommendedParams
---------------------------------------------------------
.. c:function:: void StereoConstantSpaceBP::estimateRecommendedParams( int width, int height, int\& ndisp, int\& iters, int\& levels, int\& nr_plane)
Some heuristics that tries to compute parameters (ndisp, iters, levelsand nrplane) for specified image size (widthand height).
.. index:: gpu::StereoConstantSpaceBP::operator ()
gpu::StereoConstantSpaceBP::operator ()
-------------------------------------------
.. c:function:: void StereoConstantSpaceBP::operator()( const GpuMat\& left, const GpuMat\& right, GpuMat\& disparity)
.. c:function:: void StereoConstantSpaceBP::operator()( const GpuMat\& left, const GpuMat\& right, GpuMat\& disparity, Stream\& stream)
The stereo correspondence operator. Finds the disparity for the specified rectified stereo pair.
:param left: Left image; supports ``CV_8UC1`` , ``CV_8UC3`` and ``CV_8UC4`` types.
:param right: Right image with the same size and the same type as the left one.
:param disparity: Output disparity map. If ``disparity`` is empty output type will be ``CV_16SC1`` , otherwise output type will be ``disparity.type()`` .
:param stream: Stream for the asynchronous version.
.. index:: gpu::DisparityBilateralFilter
.. _gpu::DisparityBilateralFilter:
gpu::DisparityBilateralFilter
-----------------------------
.. c:type:: gpu::DisparityBilateralFilter
The class for disparity map refinement using joint bilateral filtering. ::
class CV_EXPORTS DisparityBilateralFilter
{
public:
enum { DEFAULT_NDISP = 64 };
enum { DEFAULT_RADIUS = 3 };
enum { DEFAULT_ITERS = 1 };
explicit DisparityBilateralFilter(int ndisp = DEFAULT_NDISP,
int radius = DEFAULT_RADIUS, int iters = DEFAULT_ITERS);
DisparityBilateralFilter(int ndisp, int radius, int iters,
float edge_threshold, float max_disc_threshold,
float sigma_range);
void operator()(const GpuMat& disparity, const GpuMat& image,
GpuMat& dst);
void operator()(const GpuMat& disparity, const GpuMat& image,
GpuMat& dst, Stream& stream);
...
};
The class implements Q. Yang algorithm
qx_csbp
.
.. index:: gpu::DisparityBilateralFilter::DisparityBilateralFilter
gpu::DisparityBilateralFilter::DisparityBilateralFilter
-----------------------------------------------------------
.. c:function:: DisparityBilateralFilter::DisparityBilateralFilter( int ndisp = DEFAULT_NDISP, int radius = DEFAULT_RADIUS, int iters = DEFAULT_ITERS)
.. c:function:: DisparityBilateralFilter::DisparityBilateralFilter( int ndisp, int radius, int iters, float edge_threshold, float max_disc_threshold, float sigma_range)
DisparityBilateralFilter constructors.
:param ndisp: Number of disparities.
:param radius: Filter radius.
:param iters: Number of iterations.
:param edge_threshold: Threshold for edges.
:param max_disc_threshold: Constant to reject outliers.
:param sigma_range: Filter range.
.. index:: gpu::DisparityBilateralFilter::operator ()
gpu::DisparityBilateralFilter::operator ()
----------------------------------------------
.. c:function:: void DisparityBilateralFilter::operator()( const GpuMat\& disparity, const GpuMat\& image, GpuMat\& dst)
.. c:function:: void DisparityBilateralFilter::operator()( const GpuMat\& disparity, const GpuMat\& image, GpuMat\& dst, Stream\& stream)
Refines disparity map using joint bilateral filtering.
:param disparity: Input disparity map; supports ``CV_8UC1`` and ``CV_16SC1`` types.
:param image: Input image; supports ``CV_8UC1`` and ``CV_8UC3`` types.
:param dst: Destination disparity map; will have the same size and type as ``disparity`` .
:param stream: Stream for the asynchronous version.
.. index:: gpu::drawColorDisp
gpu::drawColorDisp
----------------------
.. c:function:: void gpu::drawColorDisp(const GpuMat\& src_disp, GpuMat\& dst_disp, int ndisp)
.. c:function:: void gpu::drawColorDisp(const GpuMat\& src_disp, GpuMat\& dst_disp, int ndisp, const Stream\& stream)
Does coloring of disparity image.
:param src_disp: Source disparity image. Supports ``CV_8UC1`` and ``CV_16SC1`` types.
:param dst_disp: Output disparity image. Will have the same size as ``src_disp`` and ``CV_8UC4`` type in ``BGRA`` format (alpha = 255).
:param ndisp: Number of disparities.
:param stream: Stream for the asynchronous version.
This function converts
:math:`[0..ndisp)` interval to
:math:`[0..240, 1, 1]` in ``HSV`` color space, than convert ``HSV`` color space to ``RGB`` .
.. index:: gpu::reprojectImageTo3D
gpu::reprojectImageTo3D
---------------------------
.. c:function:: void gpu::reprojectImageTo3D(const GpuMat\& disp, GpuMat\& xyzw, const Mat\& Q)
.. c:function:: void gpu::reprojectImageTo3D(const GpuMat\& disp, GpuMat\& xyzw, const Mat\& Q, const Stream\& stream)
Reprojects disparity image to 3D space.
:param disp: Input disparity image; supports ``CV_8U`` and ``CV_16S`` types.
:param xyzw: Output 4-channel floating-point image of the same size as ``disp`` . Each element of ``xyzw(x,y)`` will contain the 3D coordinates ``(x,y,z,1)`` of the point ``(x,y)`` , computed from the disparity map.
:param Q: :math:`4 \times 4` perspective transformation matrix that can be obtained via :ref:`StereoRectify` .
:param stream: Stream for the asynchronous version.
See also:
:func:`reprojectImageTo3D` .