Opencv learning notes - loading and saving images

Catalog

Image loading ：imread() function

Image saving ：imwrite() function

Code

---

Image loading ：imread() function

Mat imread(const string& filename, int flags = IMREAD_COLOR  )

Parameter one ： The name of the image

Parameter two ： Read tag , Used to select how to read pictures , The default value is IMREAD_COLOR,flag The setting of the value is related to the color format used to read the picture .

IMREAD_COLOR：        Always read three channel images

IMREAD_GRAYSCALE:  Always read single channel

IMREAD_ANYCOLOR:    The number of channels is determined by the actual number of channels in the file （ No more than 3）

IMREAD_ANYDEPTH：  Allow loading more than 8bit depth

IMREAD_UNCHANGED: （ When reading an image , Keep in image alpha passageway ）

Image format types are supported ;

Image saving ：imwrite() function

bool imwrite(const string& filename, 
             InputArray image,
             const vector<int>& params = vector<int>())

  Parameter one ： Save the given file name , Extension ：

                jpg perhaps jpeg、jp2、tif or tiff、png（ Recommended ）、bmp、ppm、pgm

Parameter two ： Stored input image .

Parameter 3 ： Data required for writing to a special type of file

Code

//  Read images 
Mat image = imread("1.jpg");
//  Judge whether the reading is successful 
if(image.data == NULL) {
   return ;
}
//  Show 
imshow("readImg", image);

//  Save image 
if(!imwrite("1To2.jpg", image)) {
    return ;
}