How to scale image using Java

In this post we will see how can we scale an image to a desired dimension. 


In the following code snippet the scaleImage method is responsible for scaling the source image to the given height & width. Instead of overwriting the original file the code creates a new file for the scaled image version.



public static String  scaleImage(String imgSrc, int width, int height, String dest){
 try{
File f = new File(imgSrc);

//Reads the Image from the given URL
BufferedImage img = ImageIO.read(f);

//Scales the BufferedImage to the desired dimensions
   Image scaledImg = img.getScaledInstance(width, height, Image.SCALE_AREA_AVERAGING);
   
   //'coz the Image object cannot be written to disk directly 
   //We have to recreate a new BufferedImage instance from the scaled Image instance
   BufferedImage biScaledImg = toBufferedImage(scaledImg, BufferedImage.TYPE_INT_RGB);
     
   //Writes the file on to the disk at the given destination
   ImageIO.write(biScaledImg, "jpeg", new File(dest));
}
catch(IOException e){
return "Exception occurred while scaling the Image. Exception: "+e.getMessage();
}

return dest;
}


/**
* Method to create BufferedImage Instance from given Image Object
*/
private static BufferedImage toBufferedImage(Image image, int type) {
   int w = image.getWidth(null);
   int h = image.getHeight(null);
   BufferedImage result = new BufferedImage(w, h, type);
   Graphics2D g = result.createGraphics();
   g.drawImage(image, 0, 0, null);
   g.dispose();
   return result;
}



You can download the complete source code from here


It should be noted that if the new height & width is greater than the source image height & width then the resultant image will be a pixelated image.

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