This was slightly too long for a comment, sorry. ;-)
Here's some sample code, should be properly commented to help you understand what it does. Had fun writing it...
What it does, is creating and displaying 6 images (of random noise). There will be 3 different images, each created in two different ways. 4 will use a banded model and 2 interleaved model. For the banded models, it shows how to create them, both using single and multidimensional arrays.
import java.awt.Point;
import java.awt.Transparency;
import java.awt.Window;
import java.awt.color.ColorSpace;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BandedSampleModel;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.ComponentColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.PixelInterleavedSampleModel;
import java.awt.image.Raster;
import java.awt.image.WritableRaster;
import java.util.Arrays;
import java.util.Random;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
import javax.swing.WindowConstants;
public class BufferedImageTester {
public static void main(String[] args) {
// Part I
// Dimensions, number of bands and other setup
int width = 300;
int height = 200;
int bands = 3; // 4 works too, if you want alpha
int bandSize = width * height;
Point origin = new Point(0, 0);
// Create backing data for single array banded model
byte[] singleData = new byte[bandSize * bands];
int[] singleBankIndices = createIndices(bands, 0, 0); // 0, 0, 0
int[] singleBandOffsets = createIndices(bands, 0, bandSize); // 0, bandSize, 2 * bandSize
// Create buffer for single array
DataBufferByte singleBuffer = new DataBufferByte(singleData, singleData.length, 0);
// Create raster directly from buffer
WritableRaster bandedRaster1 = Raster.createBandedRaster(singleBuffer, width, height, width, singleBankIndices, singleBandOffsets, origin);
System.out.println("bandedRaster1: " + bandedRaster1);
// Create raster from sample model and buffer
BandedSampleModel singleModel = new BandedSampleModel(DataBuffer.TYPE_BYTE, width, height, width, singleBankIndices, singleBandOffsets);
WritableRaster bandedRaster2 = Raster.createWritableRaster(singleModel, singleBuffer, origin);
System.out.println("bandedRaster2: " + bandedRaster2);
// Create backing data for multiple arrays banded model
byte[][] multiData = new byte[bands][bandSize];
int[] multiBankIndices = createIndices(bands, 0, 1); // 0, 1, 2
int[] multiBandOffsets = createIndices(bands, 0, 0); // 0, 0, 0
// Create buffer for multiple arrays
DataBufferByte multiBuffer = new DataBufferByte(multiData, bandSize, multiBandOffsets);
// Create raster directly from buffer
WritableRaster bandedRaster3 = Raster.createBandedRaster(multiBuffer, width, height, width, multiBankIndices, multiBandOffsets, origin);
System.out.println("bandedRaster3: " + bandedRaster3);
// Create raster from sample model and buffer
BandedSampleModel multiModel = new BandedSampleModel(DataBuffer.TYPE_BYTE, width, height, width, multiBankIndices, multiBandOffsets);
WritableRaster bandedRaster4 = Raster.createWritableRaster(multiModel, multiBuffer, origin);
System.out.println("bandedRaster4: " + bandedRaster4);
// Now let's create a suitable color model for these kinds of rasters, with default sRGB color space
ColorModel colorModel = new ComponentColorModel(ColorSpace.getInstance(ColorSpace.CS_sRGB), bands > 3, false, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
// Create images for all of the raster types
BufferedImage image1 = new BufferedImage(colorModel, bandedRaster1, colorModel.isAlphaPremultiplied(), null);
System.out.println("image1: " + image1);
BufferedImage image2 = new BufferedImage(colorModel, bandedRaster2, colorModel.isAlphaPremultiplied(), null);
System.out.println("image2: " + image2);
BufferedImage image3 = new BufferedImage(colorModel, bandedRaster3, colorModel.isAlphaPremultiplied(), null);
System.out.println("image3: " + image3);
BufferedImage image4 = new BufferedImage(colorModel, bandedRaster4, colorModel.isAlphaPremultiplied(), null);
System.out.println("image4: " + image4);
// Fill with randomness to make it less dull
Random random = new Random();
random.nextBytes(singleData);
for (byte[] bytes : multiData) {
random.nextBytes(bytes);
}
// And finally display to prove it works just fine
showIt(image1, "Image 1: Single bank, banded raster");
showIt(image2, "Image 2: Single bank, banded, generic raster");
showIt(image3, "Image 3: Multibank, banded raster");
showIt(image4, "Image 4: Multibank, banded, generic raster");
// Part II
// Now, the single array image, could also be used to create somehting more standard (the images will *NOT* look the same, despite sharing data)
// Create raster directly from buffer
int[] interleavedOffsets = createIndices(bands, bands - 1, -1); // 2, 1, 0 (BufferedImage.TYPE_3BYTE_BGR has this order)
WritableRaster interleavedRaster1 = Raster.createInterleavedRaster(singleBuffer, width, height, bands * width, bands, interleavedOffsets, origin);
System.out.println("interleavedRaster1: " + interleavedRaster1);
// Create raster from sample model and buffer
PixelInterleavedSampleModel interleavedModel = new PixelInterleavedSampleModel(DataBuffer.TYPE_BYTE, width, height, bands, bands * width, interleavedOffsets);
WritableRaster interleavedRaster2 = Raster.createWritableRaster(interleavedModel, singleBuffer, origin);
System.out.println("interleavedRaster2: " + interleavedRaster2);
// Create images for all of the raster types
BufferedImage image5 = new BufferedImage(colorModel, interleavedRaster1, colorModel.isAlphaPremultiplied(), null);
System.out.println("image5: " + image5);
BufferedImage image6 = new BufferedImage(colorModel, interleavedRaster2, colorModel.isAlphaPremultiplied(), null);
System.out.println("image6: " + image6);
// Uncomment these lines, to better understand the difference between banded and interleaved :-)
// Arrays.fill(singleData, bandSize, 2 * bandSize, (byte) 255);
// Arrays.fill(multiData[1], (byte) 255);
// And finally display to prove it works just fine
showIt(image5, "Image 5: Single bank, interleaved raster");
showIt(image6, "Image 6: Single bank, interleaved raster");
}
private static int[] createIndices(final int count, final int start, final int increment) {
int[] indices = new int[count];
for (int i = 0; i < count; i++) {
indices[i] = start + i * increment;
}
return indices;
}
private static void showIt(final BufferedImage image, final String title) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame frame = new JFrame(title);
frame.setDefaultCloseOperation(WindowConstants.DISPOSE_ON_CLOSE);
frame.addWindowListener(new WindowAdapter() {
@Override public void windowClosed(final WindowEvent e) {
if (Window.getWindows() == null || Window.getWindows().length == 0) {
System.exit(0);
}
}
});
frame.add(new JLabel(new ImageIcon(image)));
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
});
}
}
Here's what the test output looks like:
bandedRaster1: ByteBandedRaster: width = 300 height = 200 #bands 3 minX = 0 minY = 0
bandedRaster2: sun.awt.image.SunWritableRaster@450cceb3
bandedRaster3: ByteBandedRaster: width = 300 height = 200 #bands 3 minX = 0 minY = 0
bandedRaster4: sun.awt.image.SunWritableRaster@4bd66d2f
image1: BufferedImage@1e8ee5c0: type = 0 ColorModel: #pixelBits = 24 numComponents = 3 color space = java.awt.color.ICC_ColorSpace@378dafec transparency = 1 has alpha = false isAlphaPre = false ByteBandedRaster: width = 300 height = 200 #bands 3 minX = 0 minY = 0
image2: BufferedImage@3718cb72: type = 0 ColorModel: #pixelBits = 24 numComponents = 3 color space = java.awt.color.ICC_ColorSpace@378dafec transparency = 1 has alpha = false isAlphaPre = false sun.awt.image.SunWritableRaster@450cceb3
image3: BufferedImage@3cd4c5a0: type = 0 ColorModel: #pixelBits = 24 numComponents = 3 color space = java.awt.color.ICC_ColorSpace@378dafec transparency = 1 has alpha = false isAlphaPre = false ByteBandedRaster: width = 300 height = 200 #bands 3 minX = 0 minY = 0
image4: BufferedImage@34faaa93: type = 0 ColorModel: #pixelBits = 24 numComponents = 3 color space = java.awt.color.ICC_ColorSpace@378dafec transparency = 1 has alpha = false isAlphaPre = false sun.awt.image.SunWritableRaster@4bd66d2f
interleavedRaster1: ByteInterleavedRaster: width = 300 height = 200 #numDataElements 3 dataOff[0] = 2
interleavedRaster2: ByteInterleavedRaster: width = 300 height = 200 #numDataElements 3 dataOff[0] = 2
image5: BufferedImage@39a44220: type = 5 ColorModel: #pixelBits = 24 numComponents = 3 color space = java.awt.color.ICC_ColorSpace@378dafec transparency = 1 has alpha = false isAlphaPre = false ByteInterleavedRaster: width = 300 height = 200 #numDataElements 3 dataOff[0] = 2
image6: BufferedImage@4ef16070: type = 5 ColorModel: #pixelBits = 24 numComponents = 3 color space = java.awt.color.ICC_ColorSpace@378dafec transparency = 1 has alpha = false isAlphaPre = false ByteInterleavedRaster: width = 300 height = 200 #numDataElements 3 dataOff[0] = 2
PS: Bonus points to anyone who can explain why banded rasters 1 & 2 and 3 & 4 respectively are not equal or of the same type... I think they should be, as interleaved rasters 1 & 2 are equal.