I am given a byte[] array in Java which contains the bytes for an image, and I need to output it into an image. How would I go about doing this?
Much thanks
asked Oct 16, 2009 at 19:43
Señor Reginold Francis
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5 Answers
BufferedImage img = ImageIO.read(new ByteArrayInputStream(bytes));
2 Comments
Supercreature
This doesn't answer the question, the question was for writing to an image file. This answer is for reading FROM an image file. Whats with all the up-votes?
Nick Veys
The title says that, but the question says they have a byte array and need an Image, that's what this does.
If you know the type of image and only want to generate a file, there's no need to get a BufferedImage instance. Just write the bytes to a file with the correct extension.
try (OutputStream out = new BufferedOutputStream(new FileOutputStream(path))) {
out.write(bytes);
}
Comments
From Database.
Blob blob = resultSet.getBlob("pictureBlob");
byte [] data = blob.getBytes( 1, ( int ) blob.length() );
BufferedImage img = null;
try {
img = ImageIO.read(new ByteArrayInputStream(data));
} catch (IOException e) {
e.printStackTrace();
}
drawPicture(img); // void drawPicture(Image img);
Comments
Since it sounds like you already know what format the byte[] array is in (e.g. RGB, ARGB, BGR etc.) you might be able to use BufferedImage.setRGB(...), or a combination of BufferedImage.getRaster() and WritableRaster.setPixels(...) or WritableRaster.setSamples(...). Unforunately both of these methods require you transform your byte[] into one of int[], float[] or double[] depending on the image format.
Comments
According to the Java docs, it looks like you need to use the MemoryImageSource Class to put your byte array into an object in memory, and then use Component.createImage(ImageProducer) next (passing in your MemoryImageSource, which implements ImageProducer).
