老板kinect去噪的任务下达已经有半个多月了,前期除了看了几天文献之外就打酱油了,好像每天都很忙,可是就是不知道在忙什么。这几天为了交差,就胡乱凑了几段代码,得到一个结果,也知道不行,先应付一下,再图打算。
程序思想很简单,先对静止的场景连续采样若干帧,然后对所有点在时间域取中值,对取完中值之后的无效点在空间域取最近邻,勉强将黑窟窿填上了。由于代码较长,现在奉上关键的几个片段:
- #include
- #include
- #include
- using namespace std;
-
- #ifndef _DENOISE
- #define _DENOISE
-
- const int nFrames = 9;
- const int width = 640;
- const int height = 480;
-
- class kinectDenoising
- {
- private:
- IplImage* denoisedImage;
- IplImage* frameSet[nFrames];
- unsigned int numOfFrames;
- CvRect imageROI;
- public:
- kinectDenoising();
- ~kinectDenoising();
- void addFrame(IplImage* img);
- void setImageROI(bool isUpdate = true);
- void medianFiltering();
- void nearestFiltering();
- void updateFrameSet(IplImage* img);
- void showDenoiedImage(const char* window);
- void showCurrentImage(const char* window);
- };
-
- void insertSort(unsigned short* data,int& len,unsigned short newData);
-
- #endif
这是定义的头文件,装模作样的写了一个类,在构造函数里面,除了对denoisedImage分配内存之外其他都置0,析构函数需要释放denoisedImage和frameSet数组的内存。numOfFrames本来设计为frameSet中的图像的帧数,结果由于偷懒就用了一个定长的数组。
- void kinectDenoising::setImageROI(bool isUpdate)
- {
- if(!isUpdate)
- {
- imageROI = cvRect(22,44,591,434);
- }
- else
- {
- IplImage* image8u = cvCreateImage(cvSize(width,height),IPL_DEPTH_8U,1);
- IplImage* bitImage = cvCreateImage(cvSize(width,height),IPL_DEPTH_8U,1);
-
-
- cvConvertScale(frameSet[0],image8u,255.0/4096.0);
- cvThreshold(image8u,bitImage,0,1,CV_THRESH_BINARY);
-
-
-
-
- CvMat* rowReduced = cvCreateMat(1,bitImage->width,CV_32FC1);
-
- CvMat* colReduced = cvCreateMat(bitImage->height,1,CV_32FC1);
-
- cvReduce(bitImage,rowReduced,0,CV_REDUCE_SUM);
- cvReduce(bitImage,colReduced,1,CV_REDUCE_SUM);
-
-
- for(int i=0;icols;i++)
- {
- float temp = CV_MAT_ELEM(*rowReduced,float,0,i);
- if(temp>bitImage->height/3)
- {
- imageROI.x = i;
- break;
- }
- }
-
-
- for(int i=rowReduced->cols;i>0;i--)
- {
- float temp = CV_MAT_ELEM(*rowReduced,float,0,i-1);
- if(temp>bitImage->height/3)
- {
- imageROI.width = i-imageROI.x;
- break;
- }
- }
-
-
- for(int i=0;irows;i++)
- {
- float temp = CV_MAT_ELEM(*colReduced,float,i,0);
- if(temp>bitImage->height/3)
- {
- imageROI.y = i;
- break;
- }
- }
-
-
- for(int i=colReduced->rows;i>0;i--)
- {
- float temp = CV_MAT_ELEM(*colReduced,float,i-1,0);
- if(temp>bitImage->height/3)
- {
- imageROI.height = i-imageROI.y;
- break;
- }
- }
-
-
- cvReleaseImage(&bitImage);
- cvReleaseImage(&image8u);
- cvReleaseMat(&rowReduced);
- cvReleaseMat(&colReduced);
- }
- }
这是计算深度图像的滤波范围。由于深度图像和彩色图像的视点不一致,导致了将深度图像映射到彩色图像上时有效像素会缩小,典型的现象就是在深度图像的四周会出现黑色的区域。这个函数就是用来将四周的黑色框框去掉。用OpenCV的投影的方法。由于cvReduce()函数要进行累积和的计算,为了不使数据溢出,目标数组应该用32位的浮点型(此函数只支持8位unsigned char型和32位float型)。
- void kinectDenoising::medianFiltering()
- {
-
- cvSetZero(denoisedImage);
-
- unsigned short data[nFrames];
- int total;
- for(int i=imageROI.y;i
- {
- unsigned short* denoisedImageData = (unsigned short*)(denoisedImage->imageData+denoisedImage->widthStep*i);
- for(int j=imageROI.x;j
- {
- total = 0;
- for(int k=0;k
- {
- insertSort(data,total,CV_IMAGE_ELEM(frameSet[k],unsigned short,i,j));
- }
- if(total != 0)
- {
- denoisedImageData[j] = data[total/2];
- }
- }
- }
- }
中值滤波,统计有效点并排序,然后取中值。insertSort()函数用来将值按从小到大的顺序进行插入,鉴于篇幅的关系,就不贴出来了。
- void kinectDenoising::nearestFiltering()
- {
- CvPoint topLeft,downRight;
- IplImage* tempImage = cvCloneImage(denoisedImage);
- for(int i=imageROI.y;i
- {
- unsigned short* data = (unsigned short*)(denoisedImage->imageData+denoisedImage->widthStep*i);
- for(int j=imageROI.x;j
- {
- for(int k=1;data[j]==0;k++)
- {
- topLeft = cvPoint(j-k,i-k);
- downRight = cvPoint(j+k,i+k);
- for(int m=topLeft.x;(m<=downRight.x) && (data[j]==0);m++)
- {
- if(m<0) continue;
- if(m>=width) break;
- if(topLeft.y>=0)
- {
- unsigned short temp = CV_IMAGE_ELEM(tempImage,unsigned short,topLeft.y,m);
- if(temp > 0)
- {
- data[j] = temp;
- break;
- }
- }
- if(downRight.y < height)
- {
- unsigned short temp = CV_IMAGE_ELEM(tempImage,unsigned short,downRight.y,m);
- if(temp > 0)
- {
- data[j] = temp;
- break;
- }
- }
- }
-
- for(int m=topLeft.y;(m
- {
- if(m<0) continue;
- if(m>=height) break;
- if(topLeft.x>0)
- {
- unsigned short temp = CV_IMAGE_ELEM(tempImage,unsigned short,m,topLeft.x);
- if(temp > 0)
- {
- data[j] = temp;
- break;
- }
- }
-
- if(downRight.x
- {
- unsigned short temp = CV_IMAGE_ELEM(tempImage,unsigned short,m,downRight.x);
- if(temp > 0)
- {
- data[j] = temp;
- break;
- }
- }
- }
- }
- }
- }
- cvReleaseImage(&tempImage);
- }
最后是中值滤波,从最内层开始,一层层往外扩,直到找到有效值为止。
运行结果:
源图像:
结果图像:
附注:本来这个程序是在8位图像上进行的。先取得16位的unsigned short型深度图像,然后通过cvConvertScale()函数将其转化为8位的unsigned char型,结果在进行去噪的时候怎么都不对,将unsigned char型的数据放到matlab中一看,发现在unsigned short型数据中为0值的像素莫名其妙的在unsigned char型里有了一个很小的值(比如说1, 2, 3, 4, 5什么的,就是不为0)。很奇怪,不知道OpenCV中是怎么搞的。看来还是源数据靠谱,于是将其改为16位的unsigned short型,结果形势一片大好。
http://blog.csdn.net/chenli2010/article/details/7006573