int array to BufferedImage

问题

I'm making with the Robot class a printscreen and I convert the BufferedImage into an int array. Then I want to convert the int array back to a bufferedimage but that gives an error. This is my code:

Dimension screen = Toolkit.getDefaultToolkit().getScreenSize();
BufferedImage printscreen = robot.createScreenCapture(new Rectangle(screen));
int[] pixels = ((DataBufferInt) printscreen.getRaster().getDataBuffer()).getData();

BufferedImage image = new BufferedImage(screen.width, screen.height, BufferedImage.TYPE_INT_RGB);
WritableRaster raster = (WritableRaster) image.getRaster();
raster.setPixels(0, 0, screen.width, screen.height, pixels);

But I get the error: ArrayIndexOutOfBoundsException: 2073600 but why?

I'm getting the exception on this line:

raster.setPixels(0, 0, screen.width, screen.height, pixels);

EDIT: It is working if I change the second bufferedimage type to TYPE_BYTE_GRAY.

回答1:

int[] bitMasks = new int[]{0xFF0000, 0xFF00, 0xFF, 0xFF000000};
SinglePixelPackedSampleModel sm = new SinglePixelPackedSampleModel(
        DataBuffer.TYPE_INT, width, height, bitMasks);
DataBufferInt db = new DataBufferInt(pixels, pixels.length);
WritableRaster wr = Raster.createWritableRaster(sm, db, new Point());
BufferedImage image = new BufferedImage(ColorModel.getRGBdefault(), wr, false, null);

回答2:

Changed to:

getRaster().getPixels(0, 0, screen.width, screen.height, pixels)

and it works! Thanks for help anyway

回答3:

The ArrayIndexOutOfBounds exception occurs as and when you try to access an element at index which is beyond the size of the array. In this case, you're passing the array to setPixels method, which accordingly to its javadocs doesn't explicitly check for the bounds or size of the array. So you should be doing that explicitly before calling that method. e.g.

    if(x >= 0 && x < arr.length) {
        // some code
    }

This is the relevant code from SampleModel class used by WritableRaster.

    public int[] getPixels(int x, int y, int w, int h,
                           int iArray[], DataBuffer data) {

        int pixels[];
        int Offset=0;

        if (iArray != null)
            pixels = iArray;
        else
            pixels = new int[numBands * w * h];

        for (int i=y; i<(h+y); i++) {
            for (int j=x; j<(w+x); j++) {
                for(int k=0; k<numBands; k++) {
                    pixels[Offset++] = getSample(j, i, k, data);
                }
            }
        }

    return pixels;
}

回答4:

The size of pixels in raster.setPixels(0, 0, screen.width, screen.height, pixels); should be width*height*3 when you set BufferedImage.TYPE_INT_RGB.

回答5:

BufferedImage image = new BufferedImage(screen.width*3, screen.height,BufferedImage.TYPE_INT_RGB);
WritableRaster raster = (WritableRaster) image.getRaster();

raster.setPixels(0, 0, screen.width*3, screen.height, pixels);

来源：https://stackoverflow.com/questions/14416107/int-array-to-bufferedimage

标签

java

bufferedimage

pixels