Java图像处理问题

[sdfdd]

我想把一幅426*408，RGBA4444格式的RAW格式图片转为PNG，第一次程序编译成功，但在运行时出现错误：Unknow Error:java.awt.image.RasterFormatException: Data array too small (should be > 695231 )
代码如下

public class RawConvert
    {
        public static void main(String args[])
            {
                String path = args[0];
                try{
                File fl = new File(path);
                if(fl.isFile()){
                   InputStream fip = new FileInputStream(fl);
                   DataInputStream fis = new DataInputStream(fip);
                   ByteArrayOutputStream bos = new ByteArrayOutputStream();
                   byte[] buf = new byte[1024];
                   int num = 0;
                   byte[] ima = null;
                   int w = 426;
                   int h = 408;
                   while((num = fis.read(buf)) != -1) {
                       bos.write(buf,0,num);
                       }
                    ima = bos.toByteArray();
                    int[] bof = {0,1,2,3};
                    int[] bits = {4,4,4,4};
                    DataBuffer duf = new DataBufferByte(ima,ima.length);
                    WritableRaster ras = Raster.createInterleavedRaster(duf,w,h,4 * w,4,bof,null);
                    ColorModel cm = new ComponentColorModel(ColorSpace.getInstance(ColorSpace.TYPE_RGB),bits,true,false,3,DataBuffer.TYPE_BYTE);
                    BufferedImage img = new BufferedImage(cm,ras,false,null);
                    System.out.println(img);
                    ImageIO.write(img,"PNG",new File(path + ".png"));
                    fis.close();
                    fip.close();
                }
                catch(FileNotFoundException e1){
                    System.out.println("File Not Found:" + e1);
                }
                catch(IOException e2){
                    System.out.println("File Canot Read:" + e2);
                }
                catch(NullPointerException e3){
                    System.out.println("Null Parame:" + e3);
                }
                catch(Exception e4){
                    System.out.println("Unknow Error:" + e4);
                }
            }
    }

原图：


后来我把代码改为：
WritableRaster ras = Raster.createInterleavedRaster(duf,w / 2,h / 2,4 * w,4,bof,null);
再次运行，图可以显示，但不是我要的图，尺寸缩小为原来一半

我想知道问题出在哪？

[金坷垃好稀有]

直接把图片设置的相关参数加倍就是原图了

[sdfdd]

宽和高要加倍吗

[sdfdd]

自顶，上面那位既没给代码解释，又说的很含糊