Question

我有一个阈值化的二进制图像，如下所示：

我想在图像中找到所有连接的对象。

代码将采用输入图像流并且不提供。连接组件作为输出。

我已经在C中实现了它，其中存储了矩阵，可以通过A[][]格式直接访问。但是在HLS中，图像以流形式传入，我已在hls::Mat中进行了转换。我不确定我是否可以在Mat上执行元素操作，以及mat是否可用于离线操作，就像矩阵一样。

我无法弄清楚如何在Vivado HLS中实现C代码。

unsigned char paddedImg[FULL_HD_HEIGHT+2][FULL_HD_WIDTH+2] = {0};

void connectedComponents(unsigned char* Image,int width, int height, int 
connectType, int* noOfComponents, char* list)
{
unsigned char  west, north,northWest, northEast,south,east,southEast,southWest = 0;

int label = 0;
int min = 0;

for(int i=0; i<height; i++)
{
    for(int j=0; j<width; j++)
    {
        paddedImg[i+1][j+1] = Image[(i*width) + j];
    }
}

for(int i=1; i<(height+1); i++)
{
    for(int j=1; j<(width+1); j++)
    {
        west      = paddedImg[i][j-1];
        northWest = paddedImg[i-1][j-1];
        north     = paddedImg[i-1][j];
        northEast = paddedImg[i-1][j+1];

        if(paddedImg[i][j] != 0)
        {
            min = 25500;

            if(connectType == 8)
            {
                if( west != 0 || north != 0 || northWest != 0 || northEast != 0)
                {
                    if(west < min && west != 0)         min  = west;
                    if(northWest < min && northWest != 0)       min  = northWest;
                    if(north < min && north != 0)           min  = north;
                    if(northEast < min && northEast != 0)       min  = northEast;

                    paddedImg[i][j] = min;
                }
                else
                {
                    paddedImg[i][j] = ++label;
                }
            }
            else if(connectType == 4)
            {
                if( west != 0 || north != 0)
                {
                    if(west < min && west != 0)     min  = west;
                    if(north < min && north != 0)       min  = north;

                    paddedImg[i][j] = min;
                }
                else
                {
                    paddedImg[i][j] = ++label;
                }
            }
            else
            {
                printf("invalid connect type\n");
            }
        }
    }
}

for(int i=1; i<height+1; i++)
{
    for(int j=1; j<width+1; j++)
    {
        if(paddedImg[i][j] != 0)
        {   
            if(connectType == 8)
            {
                west =      paddedImg[i][j-1];
                northWest = paddedImg[i-1][j-1];
                north =     paddedImg[i-1][j];
                northEast = paddedImg[i-1][j+1];

                east =      paddedImg[i][j+1];
                southEast = paddedImg[i+1][j+1];
                south =     paddedImg[i+1][j];
                southWest = paddedImg[i+1][j-1];

                min = paddedImg[i][j];

                if(west < min && west != 0)             min  = west;
                if(northWest < min && northWest != 0)       min  = northWest;
                if(north < min && north != 0)               min  = north;
                if(northEast < min && northEast != 0)       min  = northEast;
                if(east < min && east != 0)             min  = east;
                if(southEast < min && southEast != 0)       min  = southEast;
                if(south < min && south != 0)               min  = south;
                if(southWest < min && southWest != 0)       min  = southWest;

                if(west != 0)       paddedImg[i][j-1] = min;
                if(northWest != 0)  paddedImg[i-1][j-1] = min;
                if(north != 0)      paddedImg[i-1][j] = min;
                if(northEast != 0)  paddedImg[i-1][j+1] = min;
                if(east != 0)       paddedImg[i][j+1] = min;
                if(southEast != 0)  paddedImg[i+1][j+1] = min;
                if(south != 0)      paddedImg[i+1][j] = min;
                if(southWest != 0)  paddedImg[i+1][j-1] = min;

            }
            else if(connectType == 4)
            {   
                west =      paddedImg[i][j-1];
                north =     paddedImg[i-1][j];
                east =      paddedImg[i][j+1];
                south =     paddedImg[i+1][j];

                min = paddedImg[i][j];

                if(west < min && west != 0)     min  = west;
                if(north < min && north != 0)       min  = north;
                if(east < min && east != 0)     min  = east;
                if(south < min && south != 0)       min  = south;

                if(west != 0)               paddedImg[i][j-1] = min;
                if(north != 0)              paddedImg[i-1][j] = min;
                if(east != 0)               paddedImg[i][j+1] = min;
                if(south != 0)              paddedImg[i+1][j] = min;
            }
            else
            {
                printf("invalid connect type\n");
            }
        }
    }
}

for(int i=0; i<height; i++)
{
    for(int j=0; j<width; j++)
    {
        Image[i*width + j] = paddedImg[i+1][j+1];
    }
}

*noOfComponents = min;
 }

Answer 1

您描述的算法似乎要求将整个图像加载到FPGA内存中，以允许随机访问元素。如果图像足够小，您可以通过事先将其从流读入内存来实现。

如果图像很大或者您不想缓冲整个图像，那么论文FPGA implementation of a Single Pass Connected Components Algorithm提出了一种通过一次查找连通分量的算法。

如何在VIVADO HLS中找到二进制图像中的连接对象？

1 个答案: