在没有ImageIO的情况下解码54字节BMP

Question

我一直试图弄清楚如何在不使用imageIO库的情况下解码图像BMP 54字节。到目前为止，我的算法在54偏移和我的colorTable之后循环数据没有任何意义。有人能给我一些提示继续吗？ THX

static BufferedImage img = null;

private int biWidth;
private int biHeight;
private byte[][] colorTable ;

public ConcreteImage(File path) {
    super._path = path;
    try{
        FileInputStream f = new FileInputStream(super._path);
        int content;
        int count = 0 ;
        while ((content = f.read()) != -1) {

            if(count == 18)
                biWidth = content;

            if(count == 22)
                biHeight = content;

            if(count > 54){

                /*System.out.println(content);*/
                colorTable = new byte[biHeight][biWidth];
                while((content = f.read()) != -1){
                    byte rgb[] = new byte[content];
                    for(int n = 0; n <= biHeight; n++){
                        for(int j = 0; j <= biWidth; j++){
                            colorTable[n][j] = rgb[content]; //It points out that i have an error from there.
                            colorTable[n+1][j+1] = rgb[content+1];
                            colorTable[n+2][n+2] = rgb[content+2];

                        }
                    }
                }
                System.out.println(colorTable);


            }
            count++;

        }
        f.close();