Convert image byte [] using java

[Miles Runner]

Hello,
I want a simple way to convert an Image or BufferedImage in bit array, if possible without using a temporary file. It must be possible via a ByteArrayInputStream, but how about the size to initialize? Any help on this will be appreciated. Thank you.

[NetworkeR]

Hello,
Can be viewed from the side of BufferedImage and Raster with this method getDataBuffer (). I think you read some articles before coding on this topic. I would recommend you to go for the the sun's documentation and api which they provide. It will help you a lot. Just try the above mentioned class and the method, there are few handy methods, you can test them.

[Miles Runner]

Hello,
I searched in this way, and tried this

((DataBufferByte) newImage.getRaster().getDataBuffer()).getData()

The following exception is generated:

java.lang.ClassCastException: java.awt.image.DataBufferInt can not be cast to java.awt.image.DataBufferByte
And of course a DataBufferInt.getData () returns an int [] and not a byte [].

Do you have any idea how to fix this problem. Please help

[HardWeaR]

Hello,
The BufferedImage class has the method "getRGB (int startX, int startY, int w, int h, int [] rgbArray, int offset, int scan size). They are int, byte and not, for the most generic possible. Depending on your image, it's up to you to figure out where the data in your world: 8, 16, 24 or 32 bits, or a personal config.

[cyber-noob]

Hello,
A ByteArrayOutputStream instead. For the size it did not really matter because it will be adapted as needed. But if you have the exact size or a proxy, you can avoid unnecessary resizing.

	Public static byte[] getBytes(BufferedImage img) throws IOException {
		ByteArrayOutputStream byar = new ByteArrayOutputStream();
		try {
			ImageIO.write(img, "png", byar);
		} finally {
			byar.close();
		}
		return byar.toByteArray();
	}

[Miles Runner]

Hello,
Meanwhile I found a solution:

ByteArrayOutputStream byar = new ByteArrayOutputStream();
JPEGCodec.createJPEGEncoder(byar).encodes(newImage);
byte[] b = byar.toByteArray();

So what is the best between these two statements:

ImageIO.write(newImage, "jpeg", byar);
JPEGCodec.createJPEGEncoder(baos).encodes(newImage);

In any case thank you for that clarification.