从字节数组获取bufferedImage

Question

I am trying to get back a bufferedImage from array of bytes , but I am getting an error saying bufferedimage is null . I actually tried several ways, everything ended up in the same way. Here goes my code:

1)

 byte[] arr = Base64.decode(base64String);
 BufferedImage bImageFromConvert =ImageIO.read(new  ByteArrayInputStream(arr));

2)

 InputStream in = new ByteArrayInputStream(arr);
 BufferedImage bImageFromConvert = ImageIO.read(in);

I am pretty sure my byte array contains data and I think ImageIO.read() is where my code goes wrong.

Answer 1

Try this code.Maybe it works. It worked for me.

byte[] aByteArray = {};
    int width = ;
    int height = ;

    DataBuffer buffer = new DataBufferByte(aByteArray, aByteArray.length);

    WritableRaster raster = Raster.createInterleavedRaster(buffer, width, height, 3 * width, 3, new int[] {0, 1, 2}, (Point)null);
    ColorModel cm = new ComponentColorModel(ColorModel.getRGBdefault().getColorSpace(), false, true, Transparency.OPAQUE, DataBuffer.TYPE_BYTE); 
    BufferedImage image = new BufferedImage(cm, raster, true, null);

Just add the byte, width and height to code and customize it.

Answer 2

The error is in your BufferedImage to Base64 encode method as you have posted in the comments.

You are never writing the BufferedImage to the ByteArrayOutputStream . Therefore the Base64 string is empty, and reading the empty string produces a null BufferedImage .

You should use this code to encode your image:

 BufferedImage originalImage = ImageIO.read(new File("G:\\a.jpg"));
 ByteArrayOutputStream baos = new ByteArrayOutputStream();
 ImageIO.write( originalImage, "jpg", baos );
 String base64String=Base64.encode(baos.toByteArray());

To decode the image use this code:

 byte[] arr = Base64.decode(base64String);
 BufferedImage bImageFromConvert =ImageIO.read(new ByteArrayInputStream(arr));
 System.out.println(bImageFromConvert.getWidth());