Please help to read parts of image.

Question

I have an jpeg-image.
The size of the image is 8000*8000
How can I read only first 1000*1000 pixels from the image-file without loading the whole image into the memory?
If I now loaded this 1000*1000 in memory as a BufferedImage, how can I read only pixels in range
600-700
600-700
so, 100*100, start from 600,600
Thanks in advance.

Answer 1

Thanks for the answer.
I have faced a problem with ImageIO.
If I read Image from file and then display it later, I need the double size of RAM for the image in the memory. First to put it into the memory from a file and the second read some parts from the BufferedImage to display it.
Is there any posibility to reference to the parts of the image, that was loaded to Image object, after the file was readed?
If I do it like this, i need doubled RAM size.
private Image img;
img = ImageIO.read(new File("bigImage.jpg"));
protected void paintComponent(Graphics g) {
int[] rgb = new int[600*600];
img.getRGB(0, 0, 600, 600, rgb, 0, 600);
BufferedImage img1 = new BufferedImage(600,600,BufferedImage.TYPE_INT_RGB);
img1.setRGB(0, 0, 600, 600, rgb, 0, 600);
g2D.drawImage(img1, null, 0, 0);
}