How to resize an image in Java with OpenCV?

Question

After cropping an image how can I resize it?

Mat croppedimage = cropImage( image, rect ); Mat resizeimage = croppedimage.resize( any dimension ); //need to change this line 

Answer 1

I think, you want this.

e.g.

Mat croppedimage = cropImage(image,rect); Mat resizeimage = new Mat(); Size sz = new Size(100,100); Imgproc.resize( croppedimage, resizeimage, sz ); 

Answer 2

If you want to scale an image using OpenCV java then do the following:

  import static org.opencv.imgproc.Imgproc.*;   import static org.opencv.imgcodecs.Imgcodecs.imread; 

Main code:

   Mat src  =  imread("imageName.jpg");    Mat resizeimage = new Mat();    Size scaleSize = new Size(300,200);    resize(src, resizeimage, scaleSize , 0, 0, INTER_AREA); 

For downscaling it is recommended to use: INTER_AREA and for upscaling use INTER_CUBIC

For more details: OpenCV Ref for Resize