package com.java.miscellaneous;

import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;

/**
 * This program demonstrates how to resize an image.
 *
 * @author Arif khan
 *
 */
public class ImageResizer {

	/**
	 * Resizes an image to a absolute width and height (the image may not be
	 * proportional)
	 * 
	 * @param inputImagePath
	 *            Path of the original image
	 * @param outputImagePath
	 *            Path to save the resized image
	 * @param scaledWidth
	 *            absolute width in pixels
	 * @param scaledHeight
	 *            absolute height in pixels
	 * @throws IOException
	 */
	public static void resize(String inputImagePath, String outputImagePath, int scaledWidth, int scaledHeight)
			throws IOException {
		// reads input image
		File inputFile = new File(inputImagePath);
		BufferedImage inputImage = ImageIO.read(inputFile);

		// creates output image
		BufferedImage outputImage = new BufferedImage(scaledWidth, scaledHeight, inputImage.getType());

		// scales the input image to the output image
		Graphics2D g2d = outputImage.createGraphics();
		g2d.drawImage(inputImage, 0, 0, scaledWidth, scaledHeight, null);
		g2d.dispose();

		// extracts extension of output file
		String formatName = outputImagePath.substring(outputImagePath.lastIndexOf(".") + 1);

		// writes to output file
		ImageIO.write(outputImage, formatName, new File(outputImagePath));
	}

	/**
	 * Resizes an image by a percentage of original size (proportional).
	 * 
	 * @param inputImagePath
	 *            Path of the original image
	 * @param outputImagePath
	 *            Path to save the resized image
	 * @param percent
	 *            a double number specifies percentage of the output image over the
	 *            input image.
	 * @throws IOException
	 */
	public static void resize(String inputImagePath, String outputImagePath, double percent) throws IOException {
		File inputFile = new File(inputImagePath);
		BufferedImage inputImage = ImageIO.read(inputFile);
		int scaledWidth = (int) (inputImage.getWidth() * percent);
		int scaledHeight = (int) (inputImage.getHeight() * percent);
		resize(inputImagePath, outputImagePath, scaledWidth, scaledHeight);
	}

	/**
	 * Test resizing images
	 */
	public static void main(String[] args) {
		String inputImagePath = "F:\\khan.jpeg";
		String outputImagePath1 = "F:\\khan.jpeg";
		String outputImagePath2 = "F:\\khan.jpeg";
		String outputImagePath3 = "F:\\khan.jpeg";

		try {
			// resize to a fixed width (not proportional)
			int scaledWidth = 1024;
			int scaledHeight = 768;
			ImageResizer.resize(inputImagePath, outputImagePath1, scaledWidth, scaledHeight);

			// resize smaller by 50%
			double percent = 0.5;
			ImageResizer.resize(inputImagePath, outputImagePath2, percent);

			// resize bigger by 50%
			percent = 1.5;
			ImageResizer.resize(inputImagePath, outputImagePath3, percent);

		} catch (IOException ex) {
			System.out.println("Error resizing the image.");
			ex.printStackTrace();
		}
	}

}