Thread: Images (read/write, drawing)

Here's a quick and dirty tutorial on how to draw images in Java, then save them to the file system.

Drawing an image from scratch and saving to a png:

int width = 1024;
int height = 768;
// we're going to use RBG coloring. There are a bunch of different types, though
BufferedImage image= new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
Graphics g = image.getGraphics();
// now drawing is just like painting a component
g.setColor(new Color(0.2f, 0.4f, 0.2f));
// make the background a slight shade of green
g.fillRect(0, 0, width, height);
g.setColor(new Color(1.0f, 0.0f, 0.0f));
// draw a red circle
g.drawCircle(0, 0, width, height);
// now to save the image
try
{
     ImageIO.write(image, "png", new File("test.png"));
}
catch (IOException exception)
{
     exception.printStackTrace();
}

It is possible to save to multiple file types, for a list of available formats call ImageIO.getWriterFormatNames().

Reading an image in is as easy as calling the read() method of ImageIO:

try
{
     BufferedImage myImage = ImageIO.read(new File("test.png"));
}
catch(IOException e)
{
     e.printStackTrace();
}

Happy drawing!