Develop Reference

Java drawImage() not drawing

Within my program, I have the following code:
package io.github.AdmiralSbs.DiceWars;
import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.Scanner;
public class HexDisplay extends JPanel {
private static final long serialVersionUID = 1L;
public static final int SIZE = 200;
private int height;
private int width;
private Hex[][] hex;
private BufferedImage myImage;
private Graphics drawer;
public HexDisplay(File f) throws IOException {
Scanner key = new Scanner(f);
int[] temp = commaSplit(key.nextLine());
height = temp[0];
width = temp[1];
hex = new Hex[width][height];
for (int w = 0; w < width; w++) {
for (int h = 0; h < height; h++) {
//temp = commaSplit(key.nextLine());
if (h % 2 == 0)
hex[w][h] = new Hex((int) (SIZE * (w + 0.5)),
(int) (SIZE * (h + 0.5)), SIZE);
else
hex[w][h] = new Hex((int) (SIZE * (w + 1.5)),
(int) (SIZE * (h + 0.5)), SIZE);
System.out.println(hex[w][h].getX() + " " + hex[w][h].getY());
}
}
key.close();
starting();
ImageIO.write(myImage, "jpg", new File("outPic.jpg"));
}
public void starting() {
setPreferredSize(new Dimension(400,400));
setLayout(new FlowLayout());
myImage = new BufferedImage(400, 400, BufferedImage.TYPE_INT_RGB);
drawer = myImage.getGraphics();
drawer.setColor(Color.BLUE);
drawer.fillRect(0, 0, 400, 400);
drawStuff(drawer);
repaint();
}
public int[] commaSplit(String s) {
String[] str = s.split(",");
int[] ret = new int[str.length];
for (int i = 0; i < str.length; i++) {
ret[i] = Integer.parseInt(str[i]);
}
return ret;
}
public void paintComponents(Graphics g) {
g.drawImage(myImage, 0, 0, this);
System.out.println("Painted");
}
public void drawStuff(Graphics g) {
for (int w = 0; w < width; w++) {
for (int h = 0; h < height; h++) {
hex[w][h].draw(g);
}
}
System.out.println("Drew");
revalidate();
repaint();
paintComponents(g);
}
}
What I would expect to happen is for the frame that contains this JPanel to display the image, but it does not. All System.out.println() methods are called as expected, and I am able to save the image as a .jpg file. However, the image is not displayed in the GUI. What can be done?

You have a typo:
// v
public void paintComponents(Graphics g) {
It should be paintComponent.
And should contain a call to super method:
super.paintComponent(g);
as the first line in the method

How to create a colour gradient without Javafx/AWT?

so i have a little Problem and i try to solve it since hours.
I have a BufferedImage and i want to change the colour in a fluent way f.e. from red to white.
My main:
public static void main(String[] args) {
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x != width; x++) {
for (int y = 0; y != height; y++) {
image.setRGB(x, y, color12(x, y));
try {
,,,
My method to change the color:
static int color12(int x, int y) {
int size = 100;
if (Math.abs(width / 2 - x) < size / 2 && Math.abs(height / 2 - y) < size / 2)
return new Color(255, 0, 0).getRGB();
else
return new Color(200, 200, 255).getRGB();
}
}
So i played around with the method, but i cant get it done.
My best "solution" was this:
int r = 0 ;
int b = 0;
int g = 0;
for (int i = 1; i < 255; i++)
r++;
else return new Color(r,g,b).getRGB();
Can anyone help me?

I'm not sure how you want the gradient (e.g. horizontal, vertical or diagonal), but here's an example using linear interpolation for a horizontal or vertical gradient.
import java.awt.Color;
import java.awt.image.BufferedImage;
import javax.swing.BoxLayout;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
public class ExampleFrame extends JFrame {
private static enum GradientOrientation {
HORIZONTAL, VERTICAL
};
private static BufferedImage createGradientImg(int width, int height, Color startColor, Color endColor, GradientOrientation o) {
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
int pos = o.equals(GradientOrientation.HORIZONTAL) ? x : y;
int size = o.equals(GradientOrientation.HORIZONTAL) ? width : height;
image.setRGB(x, y, getGradientRGB(startColor, endColor, pos, size));
}
}
return image;
}
private static int getGradientRGB(Color startColor, Color endColor, int pos, int size) {
double perc = (double) pos / size;
int newRed = (int) (endColor.getRed() * perc + startColor.getRed() * (1 - perc));
int newGreen = (int) (endColor.getGreen() * perc + startColor.getGreen() * (1 - perc));
int newBlue = (int) (endColor.getBlue() * perc + startColor.getBlue() * (1 - perc));
return new Color(newRed, newGreen, newBlue).getRGB();
}
public void createAndShow() {
BufferedImage img1 = createGradientImg(200, 100, Color.RED,
Color.WHITE, GradientOrientation.HORIZONTAL);
BufferedImage img2 = createGradientImg(200, 100, Color.BLUE,
Color.YELLOW, GradientOrientation.HORIZONTAL);
BufferedImage img3 = createGradientImg(200, 100, Color.WHITE,
Color.YELLOW, GradientOrientation.VERTICAL);
BufferedImage img4 = createGradientImg(200, 100, Color.BLACK,
Color.WHITE, GradientOrientation.VERTICAL);
BoxLayout layout = new BoxLayout(getContentPane(), BoxLayout.Y_AXIS);
getContentPane().setLayout(layout);
getContentPane().add(new JLabel(new ImageIcon(img1)));
getContentPane().add(new JLabel(new ImageIcon(img2)));
getContentPane().add(new JLabel(new ImageIcon(img3)));
getContentPane().add(new JLabel(new ImageIcon(img4)));
pack();
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
ExampleFrame ef = new ExampleFrame();
ef.createAndShow();
}
});
}
}

Rotate a buffered image in Java

I am trying to rotate a buffered image in java. Here is the code I am using:
public static BufferedImage rotate(BufferedImage bimg, double angle) {
int w = bimg.getWidth();
int h = bimg.getHeight();
Graphics2D graphic = bimg.createGraphics();
graphic.rotate(Math.toRadians(angle), w / 2, h / 2);
graphic.drawImage(bimg, null, 0, 0);
graphic.dispose();
return bimg;
}
I have looked a numerous stack overflow questions and answers on this topic and not been able to figure out why the image is chopped up the way it is when I try to rotate it. Here is an example showing a loaded image:
loaded image
After I click the rotate button which calls the above function with the buffered image and a 90.0 for the angle:
chopped up image
Can someone help me understand what is happening and how to fix it?

As always, the Internet to the rescue. So, this is some code which I hobbled together from other resources/post/blogs which will return a new image which is sized so it will contain the rotated image
public BufferedImage rotateImageByDegrees(BufferedImage img, double angle) {
double rads = Math.toRadians(angle);
double sin = Math.abs(Math.sin(rads)), cos = Math.abs(Math.cos(rads));
int w = img.getWidth();
int h = img.getHeight();
int newWidth = (int) Math.floor(w * cos + h * sin);
int newHeight = (int) Math.floor(h * cos + w * sin);
BufferedImage rotated = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = rotated.createGraphics();
AffineTransform at = new AffineTransform();
at.translate((newWidth - w) / 2, (newHeight - h) / 2);
int x = w / 2;
int y = h / 2;
at.rotate(rads, x, y);
g2d.setTransform(at);
g2d.drawImage(img, 0, 0, this);
g2d.setColor(Color.RED);
g2d.drawRect(0, 0, newWidth - 1, newHeight - 1);
g2d.dispose();
return rotated;
}
Updated
So, using this PNG:
And this code...
package javaapplication1.pkg040;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class TestPane extends JPanel {
private BufferedImage master;
private BufferedImage rotated;
public TestPane() {
try {
master = ImageIO.read(new File("/Volumes/Disk02/Dropbox/MegaTokyo/Miho_Small.png"));
rotated = rotateImageByDegrees(master, 0.0);
} catch (IOException ex) {
ex.printStackTrace();
}
Timer timer = new Timer(40, new ActionListener() {
private double angle = 0;
private double delta = 1.0;
#Override
public void actionPerformed(ActionEvent e) {
angle += delta;
rotated = rotateImageByDegrees(master, angle);
repaint();
}
});
timer.start();
}
#Override
public Dimension getPreferredSize() {
return master == null
? new Dimension(200, 200)
: new Dimension(master.getWidth(), master.getHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (rotated != null) {
Graphics2D g2d = (Graphics2D) g.create();
int x = (getWidth() - rotated.getWidth()) / 2;
int y = (getHeight() - rotated.getHeight()) / 2;
g2d.drawImage(rotated, x, y, this);
g2d.dispose();
}
}
public BufferedImage rotateImageByDegrees(BufferedImage img, double angle) {
double rads = Math.toRadians(angle);
double sin = Math.abs(Math.sin(rads)), cos = Math.abs(Math.cos(rads));
int w = img.getWidth();
int h = img.getHeight();
int newWidth = (int) Math.floor(w * cos + h * sin);
int newHeight = (int) Math.floor(h * cos + w * sin);
BufferedImage rotated = new BufferedImage(newWidth, newHeight, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = rotated.createGraphics();
AffineTransform at = new AffineTransform();
at.translate((newWidth - w) / 2, (newHeight - h) / 2);
int x = w / 2;
int y = h / 2;
at.rotate(rads, x, y);
g2d.setTransform(at);
g2d.drawImage(img, 0, 0, this);
g2d.dispose();
return rotated;
}
}
}
I can generate something like...

You get jumbled image result because you are drawing the rotated image into the input image itself. Instead you need to create graphic from a new BufferedImage.
public static BufferedImage rotate(BufferedImage bimg, double angle) {
int w = bimg.getWidth();
int h = bimg.getHeight();
BufferedImage rotated = new BufferedImage(w, h, bimg.getType());
Graphics2D graphic = rotated.createGraphics();
graphic.rotate(Math.toRadians(angle), w/2, h/2);
graphic.drawImage(bimg, null, 0, 0);
graphic.dispose();
return rotated;
}
Note that if you want to avoid getting cropped corners, you need to adjust width & height of the output BufferedImage.

This code reads an image from a file, rotates it by a certain angle, and writes to another file. It works fine with png images with transparency:
public static void main(String[] args) throws IOException {
BufferedImage image = ImageIO.read(
Test.class.getResourceAsStream("/resources/image.png"));
BufferedImage rotated = rotateImage(image, 45);
ImageIO.write(rotated, "png",
new FileOutputStream("resources/rotated.png"));
}
private static BufferedImage rotateImage(BufferedImage buffImage, double angle) {
double radian = Math.toRadians(angle);
double sin = Math.abs(Math.sin(radian));
double cos = Math.abs(Math.cos(radian));
int width = buffImage.getWidth();
int height = buffImage.getHeight();
int nWidth = (int) Math.floor((double) width * cos + (double) height * sin);
int nHeight = (int) Math.floor((double) height * cos + (double) width * sin);
BufferedImage rotatedImage = new BufferedImage(
nWidth, nHeight, BufferedImage.TYPE_INT_ARGB);
Graphics2D graphics = rotatedImage.createGraphics();
graphics.setRenderingHint(
RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BICUBIC);
graphics.translate((nWidth - width) / 2, (nHeight - height) / 2);
// rotation around the center point
graphics.rotate(radian, (double) (width / 2), (double) (height / 2));
graphics.drawImage(buffImage, 0, 0, null);
graphics.dispose();
return rotatedImage;
}
image.png
rotated.png (45º) ⟳
rotated.png (-45º) ⟲

You'll have to account for resizing and new width and height for the output. See: https://stackoverflow.com/a/4787898/5420880

Make a jpg a Shape [duplicate]

I was wondering whether there is any way to convert an image/graphic into a Shape? For example, can I convert the outline of a motorcycle shape into a Shape so I can then use it in Java? I know you can do it with normal squares or with rounded corners, polygons, etc. But is there a way to do a custom shape?

motorcycle.jpg
motorcycle-03.png
ImageOutline.java
This code requires some patience (when running).
import java.awt.*;
import java.awt.image.BufferedImage;
import java.awt.geom.Area;
import javax.imageio.ImageIO;
import java.io.File;
import java.util.Date;
import javax.swing.*;
/* Motorcycle image courtesy of ShutterStock
http://www.shutterstock.com/pic-13585165/stock-vector-travel-motorcycle-silhouette.html */
class ImageOutline {
public static Area getOutline(BufferedImage image, Color color, boolean include, int tolerance) {
Area area = new Area();
for (int x=0; x<image.getWidth(); x++) {
for (int y=0; y<image.getHeight(); y++) {
Color pixel = new Color(image.getRGB(x,y));
if (include) {
if (isIncluded(color, pixel, tolerance)) {
Rectangle r = new Rectangle(x,y,1,1);
area.add(new Area(r));
}
} else {
if (!isIncluded(color, pixel, tolerance)) {
Rectangle r = new Rectangle(x,y,1,1);
area.add(new Area(r));
}
}
}
}
return area;
}
public static boolean isIncluded(Color target, Color pixel, int tolerance) {
int rT = target.getRed();
int gT = target.getGreen();
int bT = target.getBlue();
int rP = pixel.getRed();
int gP = pixel.getGreen();
int bP = pixel.getBlue();
return(
(rP-tolerance<=rT) && (rT<=rP+tolerance) &&
(gP-tolerance<=gT) && (gT<=gP+tolerance) &&
(bP-tolerance<=bT) && (bT<=bP+tolerance) );
}
public static BufferedImage drawOutline(int w, int h, Area area) {
final BufferedImage result = new BufferedImage(
w,
h,
BufferedImage.TYPE_INT_RGB);
Graphics2D g = result.createGraphics();
g.setColor(Color.white);
g.fillRect(0,0,w,h);
g.setClip(area);
g.setColor(Color.red);
g.fillRect(0,0,w,h);
g.setClip(null);
g.setStroke(new BasicStroke(1));
g.setColor(Color.blue);
g.draw(area);
return result;
}
public static BufferedImage createAndWrite(
BufferedImage image,
Color color,
boolean include,
int tolerance,
String name)
throws Exception {
int w = image.getWidth();
int h = image.getHeight();
System.out.println("Get Area: " + new Date() + " - " + name);
Area area = getOutline(image, color, include, tolerance);
System.out.println("Got Area: " + new Date() + " - " + name);
final BufferedImage result = drawOutline(w,h,area);
displayAndWriteImage(result, name);
return result;
}
public static void displayAndWriteImage(BufferedImage image, String fileName) throws Exception {
ImageIO.write(image, "png", new File(fileName));
JOptionPane.showMessageDialog(null, new JLabel(new ImageIcon(image)));
}
public static void main(String[] args) throws Exception {
final BufferedImage outline = ImageIO.read(new File("motorcycle.jpg"));
BufferedImage crop = outline.getSubimage(17,35,420,270);
displayAndWriteImage(crop, "motorcycle-01.png");
BufferedImage crude = createAndWrite(crop, Color.white, false, 60, "motorcycle-02.png");
BufferedImage combo = createAndWrite(crude, Color.red, true, 0, "motorcycle-03.png");
}
}

function getArea_FastHack is build upon Andrew Thompsons work, which was very helpful.
Mine should be faster, however:
(//Edit: and sloppier, too)
import java.awt.*;
import java.awt.geom.Area;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import java.io.File;
import java.io.IOException;
/**
* CustomShape
* based on a Class from Andrew Thompson *
* Source: http://stackoverflow.com/questions/7052422/image-graphic-into-a-shape-in-java/7059497#7059497
* #author Samuel Schneider, Andrew Thompson
*
*
*/
class CustomShape {
private BufferedImage image=null;
/**
* Creates an Area with PixelPerfect precision
* #param color The color that is draws the Custom Shape
* #param tolerance The color tolerance
* #return Area
*/
public Area getArea(Color color, int tolerance) {
if(image==null) return null;
Area area = new Area();
for (int x=0; x<image.getWidth(); x++) {
for (int y=0; y<image.getHeight(); y++) {
Color pixel = new Color(image.getRGB(x,y));
if (isIncluded(color, pixel, tolerance)) {
Rectangle r = new Rectangle(x,y,1,1);
area.add(new Area(r));
}
}
}
return area;
}
public Area getArea_FastHack() {
//Assumes Black as Shape Color
if(image==null) return null;
Area area = new Area();
Rectangle r;
int y1,y2;
for (int x=0; x<image.getWidth(); x++) {
y1=99;
y2=-1;
for (int y=0; y<image.getHeight(); y++) {
Color pixel = new Color(image.getRGB(x,y));
//-16777216 entspricht RGB(0,0,0)
if (pixel.getRGB()==-16777216) {
if(y1==99) {y1=y;y2=y;}
if(y>(y2+1)) {
r = new Rectangle(x,y1,1,y2-y1);
area.add(new Area(r));
y1=y;y2=y;
}
y2=y;
}
}
if((y2-y1)>=0) {
r = new Rectangle(x,y1,1,y2-y1);
area.add(new Area(r));
}
}
return area;
}
public static boolean isIncluded(Color target, Color pixel, int tolerance) {
int rT = target.getRed();
int gT = target.getGreen();
int bT = target.getBlue();
int rP = pixel.getRed();
int gP = pixel.getGreen();
int bP = pixel.getBlue();
return(
(rP-tolerance<=rT) && (rT<=rP+tolerance) &&
(gP-tolerance<=gT) && (gT<=gP+tolerance) &&
(bP-tolerance<=bT) && (bT<=bP+tolerance) );
}
public CustomShape(String path) {
try {
BufferedImage image = ImageIO.read(new File(path));
this.image = image;
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

Here's something faster but less accurate, useful for collision checking or 2D physics.
Point[] MakePoly(BufferedImage spr,int d,int angle){
//creates an outline of a transparent image, points are stored in an array
//arg0 - BufferedImage source image
//arg1 - Int detail (lower = better)
//arg2 - Int angle threshold in degrees (will remove points with angle differences below this level; 15 is a good value)
// making this larger will make the body faster but less accurate;
int w= spr.getWidth(null); int h= spr.getHeight(null);
// increase array size from 255 if needed
int[] vertex_x=new int[255], vertex_y=new int[255], vertex_k=new int[255];
int numPoints=0, tx=0,ty=0,fy=-1,lx=0,ly=0; vertex_x[0]=0; vertex_y[0]=0; vertex_k[0]=1;
for (tx=0;tx<w;tx+=d) for (ty=0;ty<h;ty+=1) if((spr.getRGB(tx,ty)>>24) != 0x00 )
{vertex_x[numPoints]=tx; vertex_y[numPoints]=h-ty; vertex_k[numPoints]=1; numPoints++; if (fy<0) fy=ty; lx=tx; ly=ty; break; }
for (ty=0;ty<h;ty+=d) for (tx=w-1;tx>=0;tx-=1) if((spr.getRGB(tx,ty)>>24) != 0x00 && ty > ly)
{vertex_x[numPoints]=tx; vertex_y[numPoints]=h-ty; vertex_k[numPoints]=1; numPoints++; lx=tx; ly=ty; break; }
for (tx=w-1;tx>=0;tx-=d) for (ty=h-1;ty>=0;ty-=1) if((spr.getRGB(tx,ty)>>24) != 0x00 && tx < lx)
{vertex_x[numPoints]=tx; vertex_y[numPoints]=h-ty; vertex_k[numPoints]=1; numPoints ++; lx=tx; ly=ty; break; }
for (ty=h-1;ty>=0;ty-=d) for (tx=0;tx<w;tx+=1) if((spr.getRGB(tx,ty)>>24) != 0x00 && ty < ly && ty > fy)
{vertex_x[numPoints]=tx; vertex_y[numPoints]=h-ty; vertex_k[numPoints]=1; numPoints ++; lx=tx; ly=ty; break; }
double ang1,ang2; for (int i=0;i<numPoints-2;i++) {
ang1 = PointDirection(vertex_x[i],vertex_y[i], vertex_x[i+1],vertex_y[i+1]);
ang2 = PointDirection(vertex_x[i+1],vertex_y[i+1], vertex_x[i+2],vertex_y[i+2]);
if (Math.abs(ang1-ang2) <= angle) vertex_k[i+1] = 0; }
ang1 = PointDirection(vertex_x[numPoints-2],vertex_y[numPoints-2], vertex_x[numPoints-1],vertex_y[numPoints-1]);
ang2 = PointDirection(vertex_x[numPoints-1],vertex_y[numPoints-1], vertex_x[0],vertex_y[0]);
if (Math.abs(ang1-ang2) <= angle) vertex_k[numPoints-1] = 0;
ang1 = PointDirection(vertex_x[numPoints-1],vertex_y[numPoints-1], vertex_x[0],vertex_y[0]);
ang2 = PointDirection(vertex_x[0],vertex_y[0], vertex_x[1],vertex_y[1]);
if (Math.abs(ang1-ang2) <= angle) vertex_k[0] = 0;
int n=0;for (int i=0;i<numPoints;i++)if(vertex_k[i]==1)n++;
Point[] poly= new Point[n]; n=0; for (int i=0;i<numPoints;i++) if (vertex_k[i]==1)
{ poly[n]=new Point(); poly[n].x=vertex_x[i]; poly[n].y=h-vertex_y[i];n++;} return poly;
}
double PointDirection(double xfrom,double yfrom,double xto,double yto){
return Math.atan2(yto-yfrom,xto-xfrom)*180/Math.PI ;
}

Java Convert a greyscale and sepia version of an image with BufferedImage

I want to read an image and convert and output the original image, a greyscale version, and a sepia version. I am having trouble with the conversion, not very familiar with BufferedImage, and especially having problems with getRGB and setRGB method. I have this so far
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.plugins.jpeg.JPEGImageWriteParam;
import javax.imageio.stream.ImageOutputStream;
public class ChangeColor{
static BufferedImage readImage( String Pic ) throws Exception {
BufferedImage image = ImageIO.read( new File("Pic.jpg") );
return( image );
}
public static void saveImage( BufferedImage img, File file ) throws IOException {
ImageWriter writer = null;
java.util.Iterator iter = ImageIO.getImageWritersByFormatName("jpg");
if( iter.hasNext() ){
writer = (ImageWriter)iter.next();
}
ImageOutputStream ios = ImageIO.createImageOutputStream( file );
writer.setOutput(ios);
ImageWriteParam param = new JPEGImageWriteParam( java.util.Locale.getDefault() );
param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT) ;
param.setCompressionQuality(0.98f);
writer.write(null, new IIOImage( img, null, null ), param);
}
public static BufferedImage color2gray( BufferedImage inImage ) {
int width = inImage.getWidth();
int height = inImage.getHeight();
BufferedImage outImage = new BufferedImage( width, height, BufferedImage.TYPE_3BYTE_BGR );
for(int i=0; i<height; i++){
for(int j=0; j<width; j++){
Color c = new Color(image.getRGB(j, i));
int red = (int)(c.getRed() * 0.2126);
int green = (int)(c.getGreen() * 0.7152);
int blue = (int)(c.getBlue() *0.0722);
Color newColor = new Color(red+green+blue,
red+green+blue,red+green+blue);
image.setRGB(j,i,newColor.getRGB());
}
}
return( outImage );
}
public static BufferedImage color2sepia( BufferedImage inImage ) {
int width = inImage.getWidth();
int height = inImage.getHeight();
BufferedImage outImage = new BufferedImage( width, height, BufferedImage.TYPE_3BYTE_BGR );
for(int i=0; i<height; i++){
for(int j=0; j<width; j++){
Color c = new Color(image.getRGB(j, i));
int red = (int)(c.getRed());
int green = (int)(c.getGreen());
int blue = (int)(c.getBlue());
Color newColor = new Color(red* .393)+(green*.769)+(blue* .189),
(red* .349)+(green*.686)+(blue* .168),(red* .272)+(green*.534)+(blue* .131);
image.setRGB(j,i,newColor.getRGB());
}
}
return( outImage );
}
public static void main(String[] args) throws Exception {
BufferedImage colorImage, grayImage, sepiaImage;
if (args.length != 1)
System.out.println( "" );
else
{
colorImage = readImage ( args[0] );
grayImage = color2gray ( colorImage );
sepiaImage = color2sepia( colorImage );
saveImage( grayImage, new File( "greyPic.jpg" + args[0] ) );
saveImage( sepiaImage, new File( "sepiaPic.jpg"+ args[0] ) );
}
}
}
This is an image of what the output should look like:
Thank you.

Gray scaling is rather easy, sepia not so much. I stole the algorithm off the net...
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.color.ColorSpace;
import java.awt.image.BufferedImage;
import java.awt.image.ColorConvertOp;
import java.awt.image.WritableRaster;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class ColorAlteration {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
try {
BufferedImage master = ImageIO.read(new File("C:\\hold\\thumbnails\\_cg_836___Tilting_Windmills___by_Serena_Clearwater.png"));
BufferedImage gray = toGrayScale(master);
BufferedImage sepia = toSepia(master, 80);
JPanel panel = new JPanel(new GridBagLayout());
panel.add(new JLabel(new ImageIcon(master)));
panel.add(new JLabel(new ImageIcon(gray)));
panel.add(new JLabel(new ImageIcon(sepia)));
JOptionPane.showMessageDialog(null, panel);
} catch (IOException ex) {
ex.printStackTrace();
}
}
});
}
public static BufferedImage toGrayScale(BufferedImage master) {
BufferedImage gray = new BufferedImage(master.getWidth(), master.getHeight(), BufferedImage.TYPE_INT_ARGB);
// Automatic converstion....
ColorConvertOp op = new ColorConvertOp(ColorSpace.getInstance(ColorSpace.CS_GRAY), null);
op.filter(master, gray);
return gray;
}
public static BufferedImage toSepia(BufferedImage img, int sepiaIntensity) {
BufferedImage sepia = new BufferedImage(img.getWidth(), img.getHeight(), BufferedImage.TYPE_INT_RGB);
// Play around with this. 20 works well and was recommended
// by another developer. 0 produces black/white image
int sepiaDepth = 20;
int w = img.getWidth();
int h = img.getHeight();
WritableRaster raster = sepia.getRaster();
// We need 3 integers (for R,G,B color values) per pixel.
int[] pixels = new int[w * h * 3];
img.getRaster().getPixels(0, 0, w, h, pixels);
// Process 3 ints at a time for each pixel. Each pixel has 3 RGB
// colors in array
for (int i = 0; i < pixels.length; i += 3) {
int r = pixels[i];
int g = pixels[i + 1];
int b = pixels[i + 2];
int gry = (r + g + b) / 3;
r = g = b = gry;
r = r + (sepiaDepth * 2);
g = g + sepiaDepth;
if (r > 255) {
r = 255;
}
if (g > 255) {
g = 255;
}
if (b > 255) {
b = 255;
}
// Darken blue color to increase sepia effect
b -= sepiaIntensity;
// normalize if out of bounds
if (b < 0) {
b = 0;
}
if (b > 255) {
b = 255;
}
pixels[i] = r;
pixels[i + 1] = g;
pixels[i + 2] = b;
}
raster.setPixels(0, 0, w, h, pixels);
return sepia;
}
}
You can find the original posting for the sepia algorithm here
And because I'm stubborn...I changed the sepia algorithm to work with alpha based images...
public static BufferedImage toSepia(BufferedImage img, int sepiaIntensity) {
BufferedImage sepia = new BufferedImage(img.getWidth(), img.getHeight(), BufferedImage.TYPE_INT_ARGB);
// Play around with this. 20 works well and was recommended
// by another developer. 0 produces black/white image
int sepiaDepth = 20;
int w = img.getWidth();
int h = img.getHeight();
WritableRaster raster = sepia.getRaster();
// We need 3 integers (for R,G,B color values) per pixel.
int[] pixels = new int[w * h * 3];
img.getRaster().getPixels(0, 0, w, h, pixels);
for (int x = 0; x < img.getWidth(); x++) {
for (int y = 0; y < img.getHeight(); y++) {
int rgb = img.getRGB(x, y);
Color color = new Color(rgb, true);
int r = color.getRed();
int g = color.getGreen();
int b = color.getBlue();
int gry = (r + g + b) / 3;
r = g = b = gry;
r = r + (sepiaDepth * 2);
g = g + sepiaDepth;
if (r > 255) {
r = 255;
}
if (g > 255) {
g = 255;
}
if (b > 255) {
b = 255;
}
// Darken blue color to increase sepia effect
b -= sepiaIntensity;
// normalize if out of bounds
if (b < 0) {
b = 0;
}
if (b > 255) {
b = 255;
}
color = new Color(r, g, b, color.getAlpha());
sepia.setRGB(x, y, color.getRGB());
}
}
return sepia;
}

I used ##MadProgrammer code to write this code. Which I think it is much more efficient.
Using raster data of the image instead of accessing each byte of image. Although it seems it copys the data into pixels array, it is not used in the program.
You are calling getRGB each time + getWidth() + getHeight() + getRed(), getGreen() + getBlue().
Writing colors directly into your image, I think it is a bottleneck once you write a color using setRGB, you will lose graphic processor benefits. (I read it somewhere, but can't find the link now.)
Converting the color back to Color object and getting it back using getRGB().
All I did was using bit-wise operators which it is very fast and then copied the pixel arrays once I was done working with it. Function call is expensive and I avoided them.
However, thanks for the idea, #MadProgrammer.
public static BufferedImage toSepia(BufferedImage image, int sepiaIntensity) {
int width = image.getWidth();
int height = image.getHeight();
int sepiaDepth = 20;
int[] imagePixels = image.getRGB(0, 0, width, height, null, 0, width);
for (int i = 0; i < imagePixels.length; i++) {
int color = imagePixels[i];
int r = (color >> 16) & 0xff;
int g = (color >> 8) & 0xff;
int b = (color) & 0xff;
int gry = (r + g + b) / 3;
r = g = b = gry;
r = r + (sepiaDepth * 2);
g = g + sepiaDepth;
if (r > 255) {
r = 255;
}
if (g > 255) {
g = 255;
}
if (b > 255) {
b = 255;
}
// Darken blue color to increase sepia effect
b -= sepiaIntensity;
// normalize if out of bounds
if (b < 0) {
b = 0;
}
if (b > 255) {
b = 255;
}
imagePixels[i] = (color & 0xff000000) + (r << 16) + (g << 8) + b;
}
BufferedImage res = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
res.setRGB(0, 0, width, height, imagePixels, 0, width);
return res;
}

You can create a filter interface for code reuse.
FilterApp
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
public class FilterApp {
public static ClassLoader loader = FilterApp.class.getClassLoader();
public static String outputDir = "build";
public static void main(String[] args) {
try {
BufferedImage srcImage = loadImage("lobster.jpg");
File dir = new File(outputDir);
if (!dir.exists()) {
dir.mkdirs();
}
for (FilterType filter : FilterType.values()) {
BufferedImage filteredImage = filter.applyFilter(srcImage);
String filename = String.format("%s/lobster_%s", outputDir, filter.name().toLowerCase());
writeImage(filteredImage, filename, "jpg");
}
} catch (IOException e) {
e.printStackTrace();
}
}
private static BufferedImage loadImage(String filename) throws IOException {
return ImageIO.read(loader.getResourceAsStream("resources/" + filename));
}
private static void writeImage(BufferedImage image, String filename, String ext) throws IOException {
ImageIO.write(image, ext, new File(filename + '.' + ext));
}
}
FilterType
import java.awt.image.BufferedImage;
import filter.GreyscaleFilter;
import filter.ImageFilter;
import filter.InvertFilter;
import filter.SepiaFilter;
public enum FilterType {
GREYSCALE(new GreyscaleFilter()),
INVERT(new InvertFilter()),
SEPIA_10(new SepiaFilter(10));
private ImageFilter filter;
public ImageFilter getFilter() { return filter; }
public BufferedImage applyFilter(BufferedImage img) {
return this.filter.apply(img);
}
private FilterType(ImageFilter filter) {
this.filter = filter;
}
}
ImageFilter
package filter;
import java.awt.image.BufferedImage;
/** Common Interface for different filters. */
public interface ImageFilter {
public BufferedImage apply(BufferedImage img);
}
GreyscaleFilter
package filter;
import java.awt.color.ColorSpace;
import java.awt.image.BufferedImage;
import java.awt.image.ColorConvertOp;
public class GreyscaleFilter implements ImageFilter {
#Override
public BufferedImage apply(BufferedImage img) {
BufferedImage result = new BufferedImage(img.getWidth(), img.getHeight(), img.getType());
ColorConvertOp op = new ColorConvertOp(ColorSpace.getInstance(ColorSpace.CS_GRAY), null);
op.filter(img, result);
return result;
}
}
InvertFilter
package filter;
import java.awt.Color;
import java.awt.image.BufferedImage;
public class InvertFilter implements ImageFilter {
#Override
public BufferedImage apply(BufferedImage img) {
BufferedImage result = new BufferedImage(img.getWidth(), img.getHeight(), img.getType());
for (int x = 0; x < img.getWidth(); x++) {
for (int y = 0; y < img.getHeight(); y++) {
int rgb = img.getRGB(x, y);
Color color = new Color(rgb, true);
int r = 255 - color.getRed();
int g = 255 - color.getGreen();
int b = 255 - color.getBlue();
color = new Color(r, g, b, color.getAlpha());
result.setRGB(x, y, color.getRGB());
}
}
return result;
}
}
SepiaFilter
package filter;
import java.awt.Color;
import java.awt.image.BufferedImage;
// Algorithm obtained from http://stackoverflow.com/questions/21899824
public class SepiaFilter implements ImageFilter {
private int intensity;
public void setIntensity(int intensity) { this.intensity = intensity; }
public int getIntensity() { return intensity; }
public SepiaFilter(int intensity) {
this.intensity = intensity;
}
#Override
public BufferedImage apply(BufferedImage img) {
BufferedImage result = new BufferedImage(img.getWidth(), img.getHeight(), img.getType());
// Play around with this.
// 20 works well and was recommended by another developer.
// 0 produces black/white image
int sepiaDepth = 20;
int w = img.getWidth();
int h = img.getHeight();
// We need 3 integers (for R,G,B color values) per pixel.
int[] pixels = new int[w * h * 3];
img.getRaster().getPixels(0, 0, w, h, pixels);
for (int x = 0; x < img.getWidth(); x++) {
for (int y = 0; y < img.getHeight(); y++) {
int rgb = img.getRGB(x, y);
Color color = new Color(rgb, true);
int r = color.getRed();
int g = color.getGreen();
int b = color.getBlue();
int gry = (r + g + b) / 3;
r = g = b = gry;
r = r + (sepiaDepth * 2);
g = g + sepiaDepth;
if (r > 255) { r = 255; }
if (g > 255) { g = 255; }
if (b > 255) { b = 255; }
// Darken blue color to increase sepia effect
b -= this.intensity;
// normalize if out of bounds
if (b < 0) { b = 0; }
if (b > 255) { b = 255; }
color = new Color(r, g, b, color.getAlpha());
result.setRGB(x, y, color.getRGB());
}
}
return result;
}
}
Output
Source Image
Generated Images