51cto-opencv 3 1 0 圖像處理教程-04

1、OpenCV 3.1.0 圖像處理教程講師： 賈志剛E-Mail: 微博：流浪的魚-GloomyF圖像操作 讀寫圖像 讀寫像素 修改像素值讀寫圖像 imread 可以指定加載為灰度或者RGB圖像 Imwrite 保存圖像文件，類型由擴展名決定讀寫像素 讀一個GRAY像素點的像素值（CV_8UC1）Scalar intensity = img.at(y, x);或者 Scalar intensity

2、 = img.at(Point(x, y); 讀一個RGB像素點的像素值Vec3f intensity = img.at(y, x); float blue = intensity.val0;float green = intensity.val1; float red = intensity.val2;修改像素值 灰度圖像img.at(y, x) = 128; RGB三通道圖像img.at(y,x)0=128; / blue img.at(y,x)1=128; / greenimg.at(y,x)2=128; / red 空白圖像賦值img = Scalar(0);

3、 ROI選擇Rect r(10, 10, 100, 100);Mat smallImg = img(r);Vec3b與Vec3F Vec3b對應三通道的順序是blue、green、red的uchar類型數(shù)據(jù)。 Vec3f對應三通道的float類型數(shù)據(jù) 把CV_8UC1轉換到CV32F1實現(xiàn)如下：src.convertTo(dst, CV_32F);#include #include #include #include using namespace cv; using namespace std;int main(int argc, char

4、* args) Mat image = imread(D:/test.jpg, IMREAD_COLOR); if (image.empty() cout could not find the image resource. std:endl; return -1;int height = image.rows; int width = image.cols;int channels = image.channels();printf(height=%d width=%d channels=%d, height, width, channels); for (int row = 0; row height; row+) for (int col = 0; col width; col+) if (channels = 3) image.at(row, col)0 = 0; / blue image.at(row, col)1 = 0; / greennamedWindow(My Image, CV_WINDOW_AUTOSIZE); imshow(My