問題描述

我想知道如何將 RGB 圖像轉換為黑色 &白色(二進制)圖像.

I would like to know how to convert an RGB image into a black & white (binary) image.

轉換后，如何將修改后的圖像保存到磁盤?

After conversion, how can I save the modified image to disk?

推薦答案

AFAIK，你必須把它轉換成灰度，然后閾值轉換成二進制.

AFAIK, you have to convert it to grayscale and then threshold it to binary.

1.將圖像讀取為灰度圖像如果您是從磁盤讀取 RGB 圖像，那么您可以直接將其作為灰度圖像讀取，如下所示:

1. Read the image as a grayscale image If you're reading the RGB image from disk, then you can directly read it as a grayscale image, like this:

// C
IplImage* im_gray = cvLoadImage("image.jpg",CV_LOAD_IMAGE_GRAYSCALE);

// C++ (OpenCV 2.0)
Mat im_gray = imread("image.jpg",CV_LOAD_IMAGE_GRAYSCALE);

2.將RGB圖像im_rgb轉換為灰度圖像:否則，您必須將之前獲得的RGB圖像轉換為灰度圖像

2. Convert an RGB image im_rgb into a grayscale image: Otherwise, you'll have to convert the previously obtained RGB image into a grayscale image

// C
IplImage *im_rgb  = cvLoadImage("image.jpg");
IplImage *im_gray = cvCreateImage(cvGetSize(im_rgb),IPL_DEPTH_8U,1);
cvCvtColor(im_rgb,im_gray,CV_RGB2GRAY);

// C++
Mat im_rgb  = imread("image.jpg");
Mat im_gray;
cvtColor(im_rgb,im_gray,CV_RGB2GRAY);

3.轉換為二進制您可以使用自適應閾值或固定級別閾值 將您的灰度圖像轉換為二值圖像.

3. Convert to binary You can use adaptive thresholding or fixed-level thresholding to convert your grayscale image to a binary image.

例如在 C 中，您可以執(zhí)行以下操作(您也可以在 C++ 中使用 Mat 和相應的函數(shù)執(zhí)行相同的操作):

E.g. in C you can do the following (you can also do the same in C++ with Mat and the corresponding functions):

// C
IplImage* im_bw = cvCreateImage(cvGetSize(im_gray),IPL_DEPTH_8U,1);
cvThreshold(im_gray, im_bw, 128, 255, CV_THRESH_BINARY | CV_THRESH_OTSU);

// C++
Mat img_bw = im_gray > 128;

在上面的例子中，128 是閾值.

In the above example, 128 is the threshold.

4.保存到磁盤

// C
cvSaveImage("image_bw.jpg",img_bw);

// C++
imwrite("image_bw.jpg", img_bw);

這篇關于將 RGB 轉換為黑色 &OpenCV 中的白色的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！