用C语言,opencv,openmp实现连通区域标记的二遍扫描算法,结果通过窗口显示出来,算法中注意不要产生算术溢出
时间: 2024-05-12 18:16:17 浏览: 14
以下是使用C语言,OpenCV和OpenMP实现连通区域标记的二遍扫描算法的示例代码。这个程序将读取一幅灰度图像,并对其进行连通区域标记,然后通过窗口显示结果。
```c
#include <stdio.h>
#include <stdlib.h>
#include <opencv2/opencv.hpp>
#include <omp.h>
using namespace cv;
int main(int argc, char** argv)
{
if (argc != 2)
{
printf("Usage: ./connected_components <image_path>\n");
return -1;
}
Mat image = imread(argv[1], IMREAD_GRAYSCALE);
if (image.empty())
{
printf("Could not open or find the image\n");
return -1;
}
int rows = image.rows;
int cols = image.cols;
// First pass
int label = 1;
int* labels = (int*)malloc(rows * cols * sizeof(int));
#pragma omp parallel for
for (int i = 0; i < rows; i++)
{
for (int j = 0; j < cols; j++)
{
if (image.at<uchar>(i, j) > 0)
{
int label_above = (i > 0) ? labels[(i - 1) * cols + j] : 0;
int label_left = (j > 0) ? labels[i * cols + (j - 1)] : 0;
if (label_above == 0 && label_left == 0)
{
labels[i * cols + j] = label;
label++;
}
else if (label_above == 0 && label_left != 0)
{
labels[i * cols + j] = label_left;
}
else if (label_above != 0 && label_left == 0)
{
labels[i * cols + j] = label_above;
}
else
{
labels[i * cols + j] = fmin(label_above, label_left);
}
}
}
}
// Second pass
#pragma omp parallel for
for (int i = 0; i < rows; i++)
{
for (int j = 0; j < cols; j++)
{
if (labels[i * cols + j] > 0)
{
int root_label = labels[i * cols + j];
while (root_label != labels[(root_label - 1) / cols * cols + (root_label - 1) % cols])
{
root_label = labels[(root_label - 1) / cols * cols + (root_label - 1) % cols];
}
labels[i * cols + j] = root_label;
}
}
}
// Colorize the labels
Mat color_image(rows, cols, CV_8UC3);
Vec3b* colors = (Vec3b*)malloc(label * sizeof(Vec3b));
colors[0] = Vec3b(0, 0, 0); // background
for (int i = 1; i < label; i++)
{
colors[i] = Vec3b(rand() % 256, rand() % 256, rand() % 256);
}
#pragma omp parallel for
for (int i = 0; i < rows; i++)
{
for (int j = 0; j < cols; j++)
{
color_image.at<Vec3b>(i, j) = colors[labels[i * cols + j]];
}
}
// Display the results
namedWindow("Original", WINDOW_NORMAL);
imshow("Original", image);
namedWindow("Colorized", WINDOW_NORMAL);
imshow("Colorized", color_image);
waitKey(0);
free(labels);
free(colors);
return 0;
}
```
该程序使用OpenMP并行化了两次扫描算法,以加速处理。在第一次扫描中,每个像素的标签都是根据其上面和左边的像素的标签来确定的。在第二次扫描中,所有像素的标签都会被映射到其根标签上,以获得最终的连通区域标记。
最后,程序将颜色分配给每个标签,并将结果显示在窗口中。注意,程序中产生的所有内存都已经被释放。