Loading BMP into byte array using JavaFX - javafx

Question

I am trying to create a simple Bitmap class using JavaFX which allows me to load, use, modify and save a bitmap to file (for a scientific simulator). I have problem loading the image into a byte array.
1- Am I correct that each pixel will need 3 bytes space in the buffer?
2- getPixels function receives the following exception:
java.lang.ClassCastException: class javafx.scene.image.PixelFormat$ByteRgb cannot be cast to class javafx.scene.image.WritablePixelFormat (javafx.scene.image.PixelFormat$ByteRgb and javafx.scene.image.WritablePixelFormat are in unnamed module of loader 'app')
The cast to (WritablePixelFormat) was suggested by Intellij. What am I doing wrong?
3- How can I use getPixels function to load the whole image into a 2D array of RGB integers? (to make working with pixels easier)
Thanks.
public class BMP
{
byte[] buffer;
int width;
int height;
public BMP()
{
}
public void load(String filename) throws FileNotFoundException
{
//Creating an image
Image image = new Image(new FileInputStream(filename));
this.width = (int)image.getWidth();
this.height = (int)image.getHeight();
this.buffer = new byte[width * height * 3];
//Reading color from the loaded image
PixelReader pixelReader = image.getPixelReader();
//Reading pixels of the image
/*
for(int y = 0; y < height; y++) {
for(int x = 0; x < width; x++) {
//Retrieving the color of the pixel of the loaded image
Color color = pixelReader.getColor(x, y);
System.out.println(color.toString());
}
}*/
pixelReader.getPixels(
0,
0,
width,
height,
(WritablePixelFormat<ByteBuffer>) PixelFormat.getByteRgbInstance(),
buffer,
0,
width * 3
);
}
public static void main(String[] args)
{
BMP bmp1 = new BMP();
try
{
bmp1.load("e:/1.bmp");
System.out.println("Width:"+ bmp1.width + " length:" + bmp1.height);
}
catch (FileNotFoundException e)
{
e.printStackTrace();
}
}
}

Answer 1

With your loaded image and its PixelReader you can construct a WritableImage which will provide you with a PixelWriter. That should be sufficient to work with the image. I would not extract that into an array.