将一副图像转换成油画

阳光穿透心脏的1/2处 2022-08-09 11:59 196阅读 0赞

原创性声明：以下代码是本人改写自C\#语言编写的软件改写自PhotoSprite （Version 3.0 ，2006，由 联骏 编写），由使用OpenCV300编写。  
先看一下效果

![点击看大图][20151022212346092] ![点击看大图][20151022212358073]  
算法未作任何优化，优化算法可以看 [Photoshop 油画效果滤镜][Photoshop]。  
算法原理也不用细说了，源码之前，了无秘密。

## 代码 ##

cv::Mat OilPaint(cv::Mat I,int brushSize, int coarseness)
    {
        assert(!I.empty());
        if (brushSize < 1) brushSize = 1;
        if (brushSize > 8) brushSize = 8;
    
        if (coarseness < 1) coarseness = 1;
        if (coarseness > 255) coarseness = 255;
    
        int width  = I.cols;
        int height = I.rows;
    
        int lenArray = coarseness + 1;
        int* CountIntensity = new int[lenArray];
        uint* RedAverage    = new uint[lenArray];
        uint* GreenAverage  = new uint[lenArray];
        uint* BlueAverage   = new uint[lenArray];
    
        /// 图像灰度化
        Mat gray;
        cvtColor(I,gray,COLOR_BGR2GRAY);
    
    
        /// 目标图像
        Mat dst = Mat::zeros(I.size(),I.type());
    
        for(int nY = 0;nY <height; nY++)
        {
            // 油画渲染范围上下边界
            int top = nY - brushSize;
            int bottom = nY+ brushSize+1;
    
            if(top<0) top = 0;
            if(bottom >=height) bottom = height - 1;
    
            for(int nX = 0;nX<width;nX++)
            {
                // 油画渲染范围左右边界
                int left = nX - brushSize;
                int right = nX +brushSize+1;
    
                if(left<0) left = 0;
                if(right>=width) right = width - 1;
    
                //初始化数组
                for(int i = 0;i <lenArray;i++)
                {
                    CountIntensity[i] = 0;
                    RedAverage[i] = 0;
                    GreenAverage[i] = 0;
                    BlueAverage[i] = 0;
                }
    
    
                // 下面这个内循环类似于外面的大循环
                // 也是油画特效处理的关键部分
                for(int j = top;j<bottom;j++)
                {
                    for(int i = left;i<right;i++)
                    {
                        uchar intensity = static_cast<uchar>(coarseness*gray.at<uchar>(j,i)/255.0);
                        CountIntensity[intensity]++;
    
                        RedAverage[intensity]  += I.at<Vec3b>(j,i)[2];
                        GreenAverage[intensity]+= I.at<Vec3b>(j,i)[1];
                        BlueAverage[intensity] += I.at<Vec3b>(j,i)[0];
                    }
                }
    
                // 求最大值，并记录下数组索引
                uchar chosenIntensity = 0;
                int maxInstance = CountIntensity[0];
                for(int i=1;i<lenArray;i++)
                {
                    if(CountIntensity[i]>maxInstance)
                    {
                        chosenIntensity = (uchar)i;
                        maxInstance = CountIntensity[i];
                    }
                }
    
                dst.at<Vec3b>(nY,nX)[2] = static_cast<uchar>(RedAverage[chosenIntensity] / static_cast<float>(maxInstance));
                dst.at<Vec3b>(nY,nX)[1] = static_cast<uchar>(GreenAverage[chosenIntensity] /  static_cast<float>(maxInstance));
                dst.at<Vec3b>(nY,nX)[0] = static_cast<uchar>(BlueAverage[chosenIntensity] /  static_cast<float>(maxInstance));
            }
    
        }
    
        delete [] CountIntensity;
        delete [] RedAverage;
        delete [] GreenAverage;
        delete [] BlueAverage;
    
    #ifdef _DEBUG
        imshow("dst",dst);
        waitKey();
    #endif
    
        return dst;
    }

## 后续 ##

但是这样的油画效果，还是感觉欠缺了什么。好吧，再拿了一张油画纹理渲染一下吧。其实比较简单你可以使用正片叠底混合算法就可以了。  
先看一下效果。（其实你也可以认为这种效果不好看，囧）

![点击看大图][20151022212346092] ![点击看大图][20151031215959457]  
再来一张  
![点击看大图][20151031223813618] ![点击看大图][20151031223749196]  
另一张  
![点击看大图][20151101112359067] ![点击看大图][20151101112329788]

界面

![点击看大图][20151031223212308]

界面致谢，[人在旅途][Link 1]。  
好了，油画滤镜介绍完毕。

## 转载请保留以下信息 ##

<table> 
 <thead> 
  <tr> 
   <th>作者</th> 
   <th align="center">日期</th> 
   <th align="right">联系方式</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>风吹夏天</td> 
   <td align="center">2015年10月31日</td> 
   <td align="right">wincoder#qq.com</td> 
  </tr> 
 </tbody> 
</table>

[20151022212346092]: https://img-blog.csdn.net/20151022212346092
[20151022212358073]: /images/20220731/d9c697d639354e7a8b7fc12b5becea7b.png
[Photoshop]: http://www.cnblogs.com/hoodlum1980/archive/2011/01/15/1936078.html
[20151031215959457]: /images/20220731/871c8e8e83c14d67aa596173d8e995aa.png
[20151031223813618]: https://img-blog.csdn.net/20151031223813618
[20151031223749196]: /images/20220731/6e520dd37a6f455b9aab1098dab9f225.png
[20151101112359067]: https://img-blog.csdn.net/20151101112359067
[20151101112329788]: /images/20220731/9e41d01023ca45dd98d1ea5a47c486f6.png
[20151031223212308]: /images/20220731/aa87f943682e43d0a728b92b0ceb5fb5.png
[Link 1]: http://www.cnblogs.com/Imageshop/