Convert JFrame graphics into a jpeg file
Hello everyone, I have had this problem for quite a while but never thought to come and ask on a forum. I just looked around because I thought it was a simple problem that required a key word in the coding or something. Turns out, I can't find any help anywhere.
My problem is I want to turn a user specified graphic made in a simple JFrame program into a jpeg (or really any 'picture' format) but I don't know how. The way I have saved it is by saving the pixels in the pic into an array that is printed into a text file. So really, my jpeg file is a text file. This runs far too slow because I need to be able to load the pic several times in animations.
Here is the code. It's a very simple, user size specified, black and white checkered pic that is saved into a text file to either be loaded or written over by a new pic the next time you run the program:
Code :
/*Hello, welcome to SimplePic. This program:
* 1. asks weather you want to create a new pic or load the last pic created.
* 2. if you choose to make a new pic, it asks for the width and height in pixels
* 3. the program then creates a checkered pic of the specified size (or loads the last pic you made) starting with a black pixel in the top left corner always.
*To see the save file, look for a text file called 'picText.txt' in the same folder as this program. It will have 2 numbers for the first 2 lines (width then height),
*and then it will have (if word wrap is turned off; it doesn't have to be) a square of letters ababab...representing the pixel array in this program.
*
*MY MAIN PROBLEM: I want to convert this text file/pic into a jpeg or some kind of picture file so that:
* 1. a text file is not necessary
* 2. the program loads the pic much faster like it was openning a pic you drew in microsoft paint.
*I need this because I want to be able to create this pic, but then load it repeatedly in animations.
*
*Good luck and thank you.
*-Ben
*/
//needed libraries
import javax.swing.JFrame;
import java.awt.*;
import java.util.*;
import java.io.*;
public class SimplePic extends JFrame{
//variables
private Color c1 = new Color(0,0,0);//black
private Color c2 = new Color(255,255,255);//white
private char char1 = 'a';
private char char2 = 'b';
private char[][]pixels;
private int width,height;
private Container contents;
//new SimplePic
public SimplePic(int xsize,int ysize){
width=xsize;
height=ysize;
pixels=new char[xsize][ysize];
generatePic();
contents=getContentPane();
setSize(xsize,ysize);
setVisible(true);
}
//load SimplePic
public SimplePic(){
super("SimplePic");
loadPic("picText.txt");
contents=getContentPane();
setSize(width,height);
setVisible(true);
}
//generate Pic, creates a fine checkered pic based on remainders when dividing by 2
public void generatePic(){
for(int y=0;y<height;y++){//top to bottom
for(int x=0;x<width;x++){//left to right
//if x and y coordinate pixel has no remainder, set to black
if(x%2==0&&y%2==0){
pixels[x][y]=char1;
}
//if x coordinate pixel has a remainder of 1, but y does not, set to white
if(x%2==1&&y%2==0){
pixels[x][y]=char2;
}
//if y coordinate pixel has a remainder of 1, but x does not, set to white
if(x%2==0&&y%2==1){
pixels[x][y]=char2;
}
//if x and y coordinate pixel has a remainder of 1, set to black
if(x%2==1&&y%2==1){
pixels[x][y]=char1;
}
}
}
}
//render pic
public void paint(Graphics g){
super.paint(g);
Color color=c1;
for(int y=0;y<height;y++){
for(int x=0;x<width;x++){
//convert char array to colors black and white
switch(pixels[x][y]){
case 'a':color=c1;break;
case 'b':color=c2;break;
}
g.setColor(color);
g.fillRect(x,y,1,1);
}
}
}
//main method
public static void main(String[]args){
//i did not bother making any code for input error checking, this is a bare bones example
Scanner scan=new Scanner(System.in);
System.out.println("new pic or load pic? (n or l)");
String choice=scan.nextLine();
char c=choice.charAt(0);
if(c=='n'){
System.out.println("please enter width of pic (int)");
int x=scan.nextInt();
System.out.println("please enter height of pic (int)");
int y=scan.nextInt();
SimplePic newPic=new SimplePic(x,y);
newPic.savePic("picText.txt");
newPic.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
if(c=='l'){
SimplePic loadPic=new SimplePic();
loadPic.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}
//save current pic
public void savePic(String fn){
try{
PrintWriter out=new PrintWriter(new FileWriter(fn));
//the first 2 lines of the txt file are reserved for width and height
out.println(width);
out.println(height);
//turn word wrap off in the txt file to see a checkered square of letters representing the pixels array
for(int y=0;y<height;y++){
for(int x=0;x<width;x++){
out.print(pixels[x][y]);
}
out.println();
}
out.close();
System.out.println("Saved to "+fn);
}
catch(IOException e){System.out.println("Error saving to "+fn);}
}
//load previous pic
public void loadPic(String fn){
System.out.println("Reading "+fn+", loading...");
try{
BufferedReader br=new BufferedReader(new FileReader(fn));
String line;
char charLine[];
int numRows=0;
//read the first 2 lines of the txt file to get the width and height
String swidth=br.readLine();
String sheight=br.readLine();
width=Integer.parseInt(swidth);
height=Integer.parseInt(sheight);
//turn the square of letters in the txt file into the pixel array (turn word wrap off in the txt file to see more clearly)
pixels=new char[width][height];
while((line=br.readLine())!=null){
while(numRows<height){
charLine=line.toCharArray();
int x=0;
while((x<width)){
pixels[x][numRows]=charLine[x];
x++;
}
numRows++;
line=br.readLine();
}
}
br.close();
}
catch (IOException e){
System.out.println("Error reading maze plan from " + fn);
System.exit(0);
}
}
}
I think I made it as clear as possible, but if you have any questions, I'd be glad to answer them. I really need this answered.
Re: Convert JFrame graphics into a jpeg file
Have you looked at the ImageIO class?
It will write images to files.
Code :
javax.imageio.ImageIO.write((BufferedImage)theImg, "PNG", imgFile);
Re: Convert JFrame graphics into a jpeg file
Quote:
Originally Posted by
Norm
Have you looked at the ImageIO class?
It will write images to files.
Code :
javax.imageio.ImageIO.write((BufferedImage)theImg, "PNG", imgFile);
So would I make a method to replace my savePic method and use ImageIO.write instead of FileWriter? could you give some sample code regarding ImageIO.write?
Re: Convert JFrame graphics into a jpeg file
Quote:
give some sample code regarding ImageIO.write
How about this:
Code :
java.io.FileOutputStream fos = new java.io.FileOutputStream(targetPath);
//Create the pic..
Image img = ((ImageIcon)lblImg.getIcon()).getImage();
BufferedImage bi = new BufferedImage(
img.getWidth(null),
img.getHeight(null),
BufferedImage.TYPE_INT_RGB);
Graphics2D g2 = bi.createGraphics();
g2.drawImage(img, 0, 0, null);
ImageIO.write(bi, "jpg", fos);
Re: Convert JFrame graphics into a jpeg file
THANK YOU SIR!!!! I have no idea why this was so hard for me to find, but you pointed me in the right direction and I figured it out. I have been wandering around this site today a bit, and I have found you to be a regular helper, so I'm guessing you are probably quite experienced. However, if you are unable to get a question solved and it regards general logic or arrays, I would be glad to help. Just send a message. Syntax is my problem, but I think I'm pretty good with logic, I figured things out my teacher couldn't. I'm not bragging, seriously if you need help in those 2 areas, I think I may be of some assistance.
