Rotating images in J2ME using MIDP 1.0

pit — Mon, 19 May 2008 09:53:52 +0000

So you’re still using MIDP 1.0 uh? And maybe you need to rotate an image?

If this is your case, you could find useful this simple function:

public static Image rotateImage(Image image, int angle) throws Exception
{
	if(angle == 0)
	{
		return image; 
	}
	else if(angle != 180 && angle != 90 && angle != 270)
	{
		throw new Exception("Invalid angle");
	}
 
	int width = image.getWidth();
	int height = image.getHeight();
 
	int[] rowData = new int[width];
	int[] rotatedData = new int[width * height];
 
	int rotatedIndex = 0;
 
	for(int i = 0; i < height; i++)
	{
		image.getRGB(rowData, 0, width, 0, i, width, 1);
 
		for(int j = 0; j < width; j++)
		{
			rotatedIndex = 
				angle == 90 ? (height - i - 1) + j * height : 
				(angle == 270 ? i + height * (width - j - 1) : 
					width * height - (i * width + j) - 1
				);
 
			rotatedData[rotatedIndex] = rowData[j];
		}
	}
 
	if(angle == 90 || angle == 270)
	{
		return Image.createRGBImage(rotatedData, height, width, true);
	}
	else
	{
		return Image.createRGBImage(rotatedData, width, height, true);
	}
}

So, how can you use it? Nothing more than:

Image original = Image.createImage("/original_image.png");
 
Image rotated_image = rotateImage(original, 90);

Jappit.com » rotate image

Rotating images in J2ME using MIDP 1.0