opencv3/C++图像像素操作详解

今天小编就为大家分享一篇opencv3/C++图像像素操作详解,具有很好的参考价值,希望对大家有所帮助。一起跟随小编过来看看吧

RGB图像转灰度图

RGB图像转换为灰度图时通常使用:

进行转换,以下尝试通过其他对图像像素操作的方式将RGB图像转换为灰度图像。

 #include #include using namespace cv; int main() { //像素操作 Mat src,dst; src = imread("E:/image/image/daibola.jpg-600"); if(src.empty()) { printf("can not load image \n"); return -1; } namedWindow("input"); imshow("input",src); dst.create(src.size(), src.type()); for(int row = 0; row (row, col)[0]; int g = src.at(row, col)[1]; int r = src.at(row, col)[2]; dst.at(row, col)[0] = max(r,max(g,b)); dst.at(row, col)[1] = max(r,max(g,b)); dst.at(row, col)[2] = max(r,max(g,b)); } } namedWindow("output"); imshow("output",dst); waitKey(); }

同理使用min(r,min(g,b))可以看到由于选择了较小的灰度值图像会明显变暗:

图像线性增强

通过对图像像素操作(线性变换),实现图像的线性增强。

 #include #include using namespace cv; int main() { Mat src1, dst; src1 = imread("E:/image/image/im1.jpg-600"); if(src1.empty()) { printf("can not load im1 \n"); return -1; } double alpha = 1.2, beta = 50; dst = Mat::zeros(src1.size(), src1.type()); for(int row = 0; row (row, col)[0]; int g = src1.at(row, col)[1]; int r = src1.at(row, col)[2]; dst.at(row, col)[0] = saturate_cast(b*alpha + beta); dst.at(row, col)[1] = saturate_cast(g*alpha + beta); dst.at(row, col)[2] = saturate_cast(r*alpha + beta); } else if (src1.channels() == 1) { float v = src1.at(row, col); dst.at(row, col) = saturate_cast(v*alpha + beta); } } } namedWindow("output",CV_WINDOW_AUTOSIZE); imshow("output", dst); waitKey(); return 0; }

掩膜操作调整图像对比度

使用一个3×3掩模增强图像对比度:

 #include #include using namespace cv; int main() { Mat src, dst; src = imread("E:/image/image/daibola.jpg-600"); CV_Assert(src.depth() == CV_8U); if(!src.data) { printf("can not load image \n"); return -1; } src.copyTo(dst); for(int row = 1; row<(src.rows - 1); row++) { const uchar* previous = src.ptr(row - 1); const uchar* current = src.ptr(row); const uchar* next = src.ptr(row + 1); uchar* output = dst.ptr(row); for(int col = src.channels(); col <(src.cols - 1)*src.channels(); col++) { *output = saturate_cast(9 * current[col] - 2*previous[col] - 2*next[col] - 2*current[col - src.channels()] - 2*current[col + src.channels()]); output++; } } namedWindow("image", CV_WINDOW_AUTOSIZE); imshow("image",dst); waitKey(); return 0; }

像素重映射

利用cv::remap实现像素重映射;

cv::remap参数说明:

 Remap( InputArray src,// 输入图像 OutputArray dst,// 输出图像 InputArray map1,// 映射表1(CV_32FC1/CV_32FC2) InputArray map2,// 映射表2(CV_32FC1/CV_32FC2) int interpolation,// 选择的插值 int borderMode,// 边界类型(BORDER_CONSTANT) const Scalar borderValue// 颜色 )

插值方法:

 CV_INTER_NN =0, CV_INTER_LINEAR =1, CV_INTER_CUBIC =2, CV_INTER_AREA =3, CV_INTER_LANCZOS4 =4

通过像素重映射实现图像垂直翻转:

 #include using namespace cv; int main() { Mat src,dst; src = imread("E:/image/image/daibola.jpg-600"); if(src.empty()) { printf("can not load image \n"); return -1; } namedWindow("input", CV_WINDOW_AUTOSIZE); imshow("input", src); Mat mapx,mapy; mapx.create(src.size(), CV_32FC1); mapy.create(src.size(), CV_32FC1); for(int row = 0; row (row, col) = col; mapy.at(row, col) = src.rows - row - 1; } } remap(src, dst, mapx, mapy, CV_INTER_NN, BORDER_CONSTANT, Scalar(0,255,255)); namedWindow("output", CV_WINDOW_AUTOSIZE); imshow("output",dst); waitKey(); return 0; }

以上就是opencv3/C++图像像素操作详解的详细内容,更多请关注0133技术站其它相关文章!

赞(0) 打赏
未经允许不得转载:0133技术站首页 » python