Motion Analysis and Object Tracking
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.. highlight :: cpp
.. index :: accumulate
accumulate
--------------
.. c:function :: void accumulate( const Mat\& src, Mat\& dst, const Mat\& mask=Mat() )
Adds an image to the accumulator.
:param src: Input image as 1- or 3-channel, 8-bit or 32-bit floating point.
:param dst: Accumulator image with the same number of channels as input image, 32-bit or 64-bit floating-point.
:param mask: Optional operation mask.
The function adds `` src `` or some of its elements to `` dst `` :
.. math ::
\texttt{dst} (x,y) \leftarrow \texttt{dst} (x,y) + \texttt{src} (x,y) \quad \text{if} \quad \texttt{mask} (x,y) \ne 0
The function supports multi-channel images. Each channel is processed independently.
The functions `` accumulate* `` can be used, for example, to collect statistics of a scene background viewed by a still camera and for the further foreground-background segmentation.
See Also:
:func: `accumulateSquare` ,
:func: `accumulateProduct` ,
:func: `accumulateWeighted`
.. index :: accumulateSquare
accumulateSquare
--------------------
.. c:function :: void accumulateSquare( const Mat\& src, Mat\& dst, const Mat\& mask=Mat() )
Adds the square of a source image to the accumulator.
:param src: Input image as 1- or 3-channel, 8-bit or 32-bit floating point.
:param dst: Accumulator image with the same number of channels as input image, 32-bit or 64-bit floating-point.
:param mask: Optional operation mask.
The function adds the input image `` src `` or its selected region, raised to power 2, to the accumulator `` dst `` :
.. math ::
\texttt{dst} (x,y) \leftarrow \texttt{dst} (x,y) + \texttt{src} (x,y)^2 \quad \text{if} \quad \texttt{mask} (x,y) \ne 0
The function supports multi-channel images Each channel is processed independently.
See Also:
:func: `accumulateSquare` ,
:func: `accumulateProduct` ,
:func: `accumulateWeighted`
.. index :: accumulateProduct
accumulateProduct
---------------------
.. c:function :: void accumulateProduct( const Mat\& src1, const Mat\& src2, Mat\& dst, const Mat\& mask=Mat() )
Adds the per-element product of two input images to the accumulator.
:param src1: The first input image, 1- or 3-channel, 8-bit or 32-bit floating point.
:param src2: The second input image of the same type and the same size as ``src1`` .
:param dst: Accumulator with the same number of channels as input images, 32-bit or 64-bit floating-point.
:param mask: Optional operation mask.
The function adds the product of 2 images or their selected regions to the accumulator `` dst `` :
.. math ::
\texttt{dst} (x,y) \leftarrow \texttt{dst} (x,y) + \texttt{src1} (x,y) \cdot \texttt{src2} (x,y) \quad \text{if} \quad \texttt{mask} (x,y) \ne 0
The function supports multi-channel images. Each channel is processed independently.
See Also:
:func: `accumulate` ,
:func: `accumulateSquare` ,
:func: `accumulateWeighted`
.. index :: accumulateWeighted
accumulateWeighted
----------------------
.. c:function :: void accumulateWeighted( const Mat\& src, Mat\& dst, double alpha, const Mat\& mask=Mat() )
Updates a running average.
:param src: Input image as 1- or 3-channel, 8-bit or 32-bit floating point.
:param dst: Accumulator image with the same number of channels as input image, 32-bit or 64-bit floating-point.
:param alpha: Weight of the input image.
:param mask: Optional operation mask.
The function calculates the weighted sum of the input image `` src `` and the accumulator `` dst `` so that `` dst `` becomes a running average of a frame sequence:
.. math ::
\texttt{dst} (x,y) \leftarrow (1- \texttt{alpha} ) \cdot \texttt{dst} (x,y) + \texttt{alpha} \cdot \texttt{src} (x,y) \quad \text{if} \quad \texttt{mask} (x,y) \ne 0
That is, `` alpha `` regulates the update speed (how fast the accumulator "forgets" about earlier images).
The function supports multi-channel images. Each channel is processed independently.
See Also:
:func: `accumulate` ,
:func: `accumulateSquare` ,
:func: `accumulateProduct`
