Rotating an image in memory

Question

Hi
I need to rotate an image kept in a DB as a byte array. I have an Object holding the byte array of the image, and I want to create a new byte array holding the rotated image.
I use the following code:
private byte[] rotateImage(byte[] originalImageAsBytes , double radians) throws InternalException {
    ByteArrayOutputStream rotatedImageStream = null;
    try {
      BufferedImage originalImage = ImageIO.read(new ByteArrayInputStream(originalImageAsBytes)); // read the original image
      BufferedImage rotatedImage = new BufferedImage(originalImage.getHeight() , originalImage.getWidth() , originalImage.getType()); // create the rotated image
      AffineTransformOp rotationTransformOp = new AffineTransformOp(AffineTransform.getRotateInstance(radians),AffineTransformOp.TYPE_NEAREST_NEIGHBOR); // this AffineTransformOp is the actual "rotater"
      rotatedImage = rotationTransformOp.filter(originalImage,null); // perform the rotation
      // write the result
      rotatedImageStream = new ByteArrayOutputStream();
      ImageIO.write(rotatedImage, ImageIO.getReaderFormatNames()[0] , rotatedImageStream);
    } catch (IOException e) {
      throw new InternalException(e);
    return rotatedImageStream.toByteArray();
  }//rotateImageWhen I run this code I get the following exception:
java.awt.image.RasterFormatException: Transformed height (0) is less than or equ
al to 0.
at java.awt.image.AffineTransformOp.createCompatibleDestImage(AffineTran
sformOp.java:436)
at java.awt.image.AffineTransformOp.filter(AffineTransformOp.java:209)
I tried to do the following:
private byte[] rotateImage(byte[] originalImageAsBytes , double radians) throws InternalException {
    ByteArrayOutputStream rotatedImageStream = null;
    try {
      BufferedImage originalImage = ImageIO.read(new ByteArrayInputStream(originalImageAsBytes)); // read the original image
      BufferedImage rotatedImage = new BufferedImage(originalImage.getHeight() , originalImage.getWidth() , originalImage.getType()); // create the rotated image
      AffineTransformOp rotationTransformOp = new AffineTransformOp(AffineTransform.getRotateInstance(radians),AffineTransformOp.TYPE_NEAREST_NEIGHBOR); // this AffineTransformOp is the actual "rotater"
      rotationTransformOp.filter(originalImage,rotatedImage); // perform the rotation
      // write the result
      rotatedImageStream = new ByteArrayOutputStream();
      ImageIO.write(rotatedImage, ImageIO.getReaderFormatNames()[0] , rotatedImageStream);
    } catch (IOException e) {
      throw new InternalException(e);
    return rotatedImageStream.toByteArray();
  }//rotateImageBut this simply does not create the transformation. When I debug the the application I see that the filter method does not change the rotatedImage at all.
Can anyone help please?
10x

Answer 1

I'm glad I'm discussing with myself here, but again - I have more input (I would be very grateful if someone could help as well...).
I found out that what ruins my images is the type of interpolation I used. If I don't use the AffineTransformOp.TYPE_NEAREST_NEIGHBOR - the image is ruined.
However, when I use the nearest neighbor interpolation, the quality of the image is degraded.
This is the code I use now (that works but degrades the image), please feel free to let me know how can I use bilinear or bicubic interpolations, and still succeed my operation:
  private byte[] rotateImage(byte[] originalImageAsBytes , double radians) throws InternalException {
    ByteArrayOutputStream rotatedImageStream = null;
    try {
      BufferedImage originalImage = ImageIO.read(new ByteArrayInputStream(originalImageAsBytes)); // read the original image
      AffineTransform rotationTransform = new AffineTransform();
      rotationTransform.rotate(radians, originalImage.getWidth() / 2.0 , originalImage.getHeight() / 2.0);
      AffineTransformOp rotationTransformOp =
        new AffineTransformOp(rotationTransform , AffineTransformOp.TYPE_NEAREST_NEIGHBOR);
      BufferedImage rotatedImage = rotationTransformOp.filter(originalImage,null);
      // write the result
      rotatedImageStream = new ByteArrayOutputStream();
      ImageIO.write(rotatedImage, "jpg" , rotatedImageStream);
    } catch (IOException e) {
      throw new InternalException(e);
    return rotatedImageStream.toByteArray();
}//rotateImage