简介

图像混合是指二个图像的线性混合。就像大家看电影过程中，在同一时间轴上出现二个视频的叠加，是不是感觉很cool呢，那就让小编带你们了解一下吧，嘿嘿嘿。

基本原理

$g(x)=(1-sigma)f_0(x)+sigma f_1(x)(0<sigma<1)$

g(x)=(1−σ)f0​(x)+σf1​(x)(0<σ<1)

$f_0andf_1$

f0​andf1​是源图像的像素点，
$g$

g则是混合后像素点值。可以看到二个图像的像素值是线性混合相加，当
$sigma$

σ在0到1之间取值时，二个图像所占的比例也不同，这就可以做出了二个图像混合的效果啦，是不是很简单呢。

相关API

addWeighted官方描述如下，相信大家摸索一下就会了，也很简单啦。

/** @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&) */ 

示例

addWeighted(src_one, 0.5, src_two, 0.5, 0.0, dst); 

这里把二个源图像按五五开的比例线性混合，效果如下

结语

各位是不是也学会了呢，赶快试试吧！！