Opencv convertScaleAbs

void cv::convertScaleAbs(
　　cv::InputArray src, // 输入数组
　　cv::OutputArray dst, // 输出数组
　　double alpha = 1.0, // 乘数因子
　　double beta = 0.0 // 偏移量
);

// Copyright (C) 2000-2015, Intel Corporation, all rights reserved.
// Copyright (C) 2009-2011, Willow Garage Inc., all rights reserved.
// Copyright (C) 2015, OpenCV Foundation, all rights reserved.
// Copyright (C) 2015, Itseez Inc., all rights reserved.

/** @brief Scales, calculates absolute values, and converts the result to 8-bit.

On each element of the input array, the function convertScaleAbs
performs three operations sequentially: scaling, taking an absolute
value, conversion to an unsigned 8-bit type:
\f[\texttt{dst} (I)= \texttt{saturate\_cast<uchar>} (| \texttt{src} (I)* \texttt{alpha} + \texttt{beta} |)\f]
In case of multi-channel arrays, the function processes each channel
independently. When the output is not 8-bit, the operation can be
emulated by calling the Mat::convertTo method (or by using matrix
expressions) and then by calculating an absolute value of the result.
For example:
@code{.cpp}
Mat_<float> A(30,30);
randu(A, Scalar(-100), Scalar(100));
Mat_<float> B = A*5 + 3;
B = abs(B);
// Mat_<float> B = abs(A*5+3) will also do the job,
// but it will allocate a temporary matrix
@endcode
@param src input array.
@param dst output array.
@param alpha optional scale factor.
@param beta optional delta added to the scaled values.
@sa Mat::convertTo, cv::abs(const Mat&)
*/
CV_EXPORTS_W void convertScaleAbs(

　　InputArray src,

　　OutputArray dst,
　　double alpha = 1,

　　double beta = 0

);