Creating a bmp

I need to create a bmp from a byte array describing the rgb values of each pixel

EDIT: I solved the problem.

import java.io.DataInputStream;

import java.io.File;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.IOException;


public class BMP {

	private final static int BMP_CODE = 19778;

	

	byte [] bytes;

	int [][] rgbValues;

	

	public void saveBMP(int [][] rgbValues){

		this.rgbValues=rgbValues;

		try {

			FileOutputStream fos = new FileOutputStream(new File("image.bmp"));

			

			bytes = new byte[54 + 3*rgbValues.length*rgbValues[0].length + getPadding(rgbValues[0].length)*rgbValues.length];


			saveFileHeader();

			saveInfoHeader(rgbValues.length, rgbValues[0].length);

			saveRgbQuad();

			saveBitmapData(rgbValues);


			fos.write(bytes);

			

			fos.close();

			

		} catch (FileNotFoundException e) {

			

		} catch (IOException e) {

			

		}

		

	}


	private void saveFileHeader() {

		byte[]a=intToByteCouple(BMP_CODE);

		bytes[0]=a[1];

		bytes[1]=a[0];

		

		a=intToFourBytes(bytes.length);

		bytes[5]=a[0];

		bytes[4]=a[1];

		bytes[3]=a[2];

		bytes[2]=a[3];

		

		//data offset

		bytes[10]=54;

	}

	

	private void saveInfoHeader(int height, int width) {

		bytes[14]=40;

		

		byte[]a=intToFourBytes(width);

		bytes[22]=a[3];

		bytes[23]=a[2];

		bytes[24]=a[1];

		bytes[25]=a[0];

		

		a=intToFourBytes(height);

		bytes[18]=a[3];

		bytes[19]=a[2];

		bytes[20]=a[1];

		bytes[21]=a[0];

		

		bytes[26]=1;

		

		bytes[28]=24;

	}

	

	private void saveRgbQuad() {

		

	}


	private void saveBitmapData(int[][]rgbValues) {

		int i;

		

		for(i=0;i<rgbValues.length;i++){

			writeLine(i, rgbValues);

		}

		

	}

	

	private void writeLine(int row, int [][] rgbValues) {

		final int offset=54;

		final int rowLength=rgbValues[row].length;

		final int padding = getPadding(rgbValues[0].length);

		int i;

		

		for(i=0;i<rowLength;i++){

			int rgb=rgbValues[row][i];

			int temp=offset + 3*(i+rowLength*row) + row*padding;

			

			bytes[temp]    = (byte) (rgb>>16);

			bytes[temp +1] = (byte) (rgb>>8);

			bytes[temp +2] = (byte) rgb;

		}

		i--;

		int temp=offset + 3*(i+rowLength*row) + row*padding+3;

		

		for(int j=0;j<padding;j++)

			bytes[temp +j]=0;

		

	}


	private byte[] intToByteCouple(int x){

		byte [] array = new byte[2];

		

		array[1]=(byte)  x;

		array[0]=(byte) (x>>8);

		

		return array;

	}

	

	private byte[] intToFourBytes(int x){

		byte [] array = new byte[4];

		

		array[3]=(byte)  x;

		array[2]=(byte) (x>>8);

		array[1]=(byte) (x>>16);

		array[0]=(byte) (x>>24);

		

		return array;

	}

	

	private int getPadding(int rowLength){

		

		int padding = (3*rgbValues[0].length)%4;

		if(padding!=0)

			padding=4-padding;

		

		

		return padding;

	}

	

}

Where the matrix rgbValues is generated (randomly at the moment) with this method:

private static int[][] generateRGBMatrix() {

		int size=50;

		

		int[][]mat=new int[size][size];

		Random r=new Random();

		

		for(int i=0;i<mat.length;i++){

			for(int j=0;j<mat[0].length;j++){

				int left   = (r.nextInt(254)+1)<<16;

				int center = (r.nextInt(254)+1)<<8;

				int right  = r.nextInt(254)+1;

				mat[i][j]  = left|center|right;

			}

		}

		

		return mat;

	}

Edited by eafkuor, 11 December 2010 - 02:37 PM.