Image Processing using OpenCV in Java | Set 14 ( Sharpness Enhancement )

In this article we will learn how to enhance sharpness of an image using OpenCv library.
In order to enhance sharpness we will use Gaussian filter. Gaussian filter reduces the noise in the image and makes it look better (or higher resolution).

At first we need to setup OpenCV for java, we recommend to use eclipse for the same since it is easy to use and setup.For installation refer to http://docs.opencv.org/2.4/doc/tutorials/introduction/java_eclipse/java_eclipse.html

Methods required for sharpness enhancement.

GaussianBlur(source, destination, new Size(0, 0), sigmaX) – This method resides in Imgproc package of OpenCv.
Syntax:

Imgproc.GaussianBlur(source, destination, new Size(0, 0), sigmaX)
parameters:
source - source image
destination - destination image
new Size(0, 0) - Gaussian kernel size
sigmaX - Gaussian kernel standard deviation in X direction

addWeighted(InputArray src1, alpha, src2, beta, gamma, OutputArray dst) - This method resides in Core package of OpenCv. Syntax:

Core.addWeighted(InputArray src1, alpha, src2, beta, gamma, OutputArray dst)
parameters:
src1 - first input array
alpha - weight of the first array elements
src2 - second input array of the same size and channel number as src1
beta - weight of the second array elements
gamma - scalar added to each sum
dst - output array that has the same size and number of channels as the input arrays

imread() - This method is used to read images as Mat objects which are rendered by OpenCV.
Syntax:

Imgcodecs.imread(filename);
parameters:
filename: filename of the image file.If the image is 
in another directory whole path of image must be mentioned.

imwrite() - This method is used to write Mat objects to image file.
Syntax:

Imgcodecs.imwrite(filename, mat_img);
parameters:
filename: filename of the image file.If the image is 
in another directory whole path of image must be mentioned.
mat_img: resultant mat object.

package ocv; 
  
import org.opencv.core.Core; 
import org.opencv.core.Mat; 
import org.opencv.core.Size; 
import org.opencv.imgcodecs.Imgcodecs; 
import org.opencv.imgproc.Imgproc; 
  
public class Main { 
   public static void main( String[] args ) 
   { 
      try{ 
         // For proper execution of native libraries 
         // Core.NATIVE_LIBRARY_NAME must be loaded before 
            // calling any of the opencv methods 
         System.loadLibrary( Core.NATIVE_LIBRARY_NAME ); 
  
         // Input image 
         Mat source = 
         Imgcodecs.imread("E://input.jpg", Imgcodecs.CV_LOAD_IMAGE_COLOR); 
         Mat destination = new Mat(source.rows(), source.cols(), source.type()); 
  
         // filtering 
         Imgproc.GaussianBlur(source, destination, new Size(0, 0), 10); 
         Core.addWeighted(source, 1.5, destination, -0.5, 0, destination); 
  
         // writing output image 
         Imgcodecs.imwrite("E://output.jpg", destination); 
      }catch (Exception e) { 
      } 
   } 
} 

/div>

Note: The code will not work in online ide since it requires image in hard drive.

Output:

input.jpg

output.jpg

Try to notice minor improvement in resolution

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

Image Processing using OpenCV in Java | Set 14 ( Sharpness Enhancement )

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