A flipped image is an image that is generated by a mirror-reversal of an original across a horizontal axis or a vertical axis. The following tutorial will make you familiar with:
- Reading Image From File using javax.imageio.ImageIO
- Flipping the Image Horizontally
- Flipping the Image Vertically
- Saving The Images back to File System using javax.imageio.ImageIO
- General Graphics2D operation
As a demo, this program will flip a FaceBook logo horizontally and vertically. The flipped images along with its original are at the end of this post.
package com.kushal.graphics;
/**
* Author - Kushal Paudyal
* www.sanjaal.com/java
* Last Modified On: 2009-09-18
*
* --Reads Image From File
* --Flips Image Horizontally
* --Flips Image Vertically
* --Saves The Images To File System
*/
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class ImageFlip {
/**
* This method flips the image horizontally
* @param img --> BufferedImage Object to be flipped horizontally
* @return
*/
public BufferedImage horizontalflip(BufferedImage img) {
int w = img.getWidth();
int h = img.getHeight();
BufferedImage dimg = new BufferedImage(w, h, img.getType());
Graphics2D g = dimg.createGraphics();
/**
* img - the specified image to be drawn. This method does nothing if
* img is null. dx1 - the x coordinate of the first corner of the
* destination rectangle. dy1 - the y coordinate of the first corner of
* the destination rectangle. dx2 - the x coordinate of the second
* corner of the destination rectangle. dy2 - the y coordinate of the
* second corner of the destination rectangle. sx1 - the x coordinate of
* the first corner of the source rectangle. sy1 - the y coordinate of
* the first corner of the source rectangle. sx2 - the x coordinate of
* the second corner of the source rectangle. sy2 - the y coordinate of
* the second corner of the source rectangle. observer - object to be
* notified as more of the image is scaled and converted.
*
*/
g.drawImage(img, 0, 0, w, h, w, 0, 0, h, null);
g.dispose();
return dimg;
}
/**
* This method flips the image vertically
* @param img --> BufferedImage object to be flipped
* @return
*/
public BufferedImage verticalflip(BufferedImage img) {
int w = img.getWidth();
int h = img.getHeight();
BufferedImage dimg = new BufferedImage(w, h, img.getColorModel()
.getTransparency());
Graphics2D g = dimg.createGraphics();
g.drawImage(img, 0, 0, w, h, 0, h, w, 0, null);
g.dispose();
return dimg;
}
/**
* This method reads an image from the file
* @param fileLocation -- > eg. "C:/testImage.jpg"
* @return BufferedImage of the file read
*/
public BufferedImage readImage(String fileLocation) {
BufferedImage img = null;
try {
img = ImageIO.read(new File(fileLocation));
} catch (IOException e) {
e.printStackTrace();
}
return img;
}
/**
* This method writes a buffered image to a file
* @param img -- > BufferedImage
* @param fileLocation --> e.g. "C:/testImage.jpg"
* @param extension --> e.g. "jpg","gif","png"
*/
public void writeImage(BufferedImage img, String fileLocation,
String extension) {
try {
BufferedImage bi = img;
File outputfile = new File(fileLocation);
ImageIO.write(bi, extension, outputfile);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* Testing the various methods
*/
public static void main(String args[]) {
String inputImageLocation = "C:/temp/myImage.jpg";
String outputImageLocationHF = "C:/temp/myImageHorizontalFlip.jpg";
String outputImageLocationVF = "C:/temp/myImageVerticalFlip.jpg";
String extension = "jpg";
ImageFlip flipper = new ImageFlip();
/**
* Reading image from the file
*/
System.out.println("Reading Image From :" + inputImageLocation);
BufferedImage inputImage = flipper.readImage(inputImageLocation);
BufferedImage img = inputImage;
/**
* Doing Horizontal Flip and saving to file
*/
System.out.print("\nDoing Horizontal Flip...");
img = flipper.horizontalflip(img);
System.out.println("Completed");
flipper.writeImage(img, outputImageLocationHF, extension);
System.out.println("Flipped Image Saved To: " + outputImageLocationHF);
/**
* Doing Vertical Flip and saving to file
*/
System.out.print("\nDoing Vertical Flip...");
img = inputImage;
img = flipper.verticalflip(img);
System.out.println("Completed");
flipper.writeImage(img, outputImageLocationVF, extension);
System.out.println("Flipped Image Saved To: " + outputImageLocationVF);
}
}
====================
The output of this program:
Reading Image From :C:/temp/myImage.jpg
Doing Horizontal Flip…Completed
Flipped Image Saved To: C:/temp/myImageHorizontalFlip.jpg
Doing Vertical Flip…Completed
Flipped Image Saved To: C:/temp/myImageVerticalFlip.jpg
The Original Image:
Image Flipped Horizontally:
Image Flipped Vertically:
Originally posted 2009-09-18 14:10:11.
