JavaFX Image from a byte array

JavaFXImageConversion.java

import javafx.scene.image.Image;
import javax.imageio.ImageIO;
import java.awt.image.*;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;

 public Image getJavaFXImage(byte[] rawPixels, int width, int height) {
    ByteArrayOutputStream out = new ByteArrayOutputStream();
    try {
        ImageIO.write((RenderedImage) createBufferedImage(rawPixels, width, height), "png", out);
        out.flush();
        } catch (IOException ex) {
            Logger.getLogger(ImageUtils.class.getName()).log(Level.SEVERE, null, ex);
        }
    ByteArrayInputStream in = new ByteArrayInputStream(out.toByteArray());
    return new javafx.scene.image.Image(in);
    }

private BufferedImage createBufferedImage(byte[] pixels, int width, int height) {
    SampleModel sm = getIndexSampleModel(width, height);
    DataBuffer db = new DataBufferByte(pixels, width*height, 0);
    WritableRaster raster = Raster.createWritableRaster(sm, db, null);
    IndexColorModel cm = getDefaultColorModel();
    BufferedImage image = new BufferedImage(cm, raster, false, null);
    return java.awt.image;
}

private SampleModel getIndexSampleModel(int width, int height) {
    IndexColorModel icm = getDefaultColorModel();
    WritableRaster wr = icm.createCompatibleWritableRaster(1, 1);
    SampleModel sampleModel = wr.getSampleModel();
    sampleModel = sampleModel.createCompatibleSampleModel(width, height);
    return sampleModel;
}

private IndexColorModel getDefaultColorModel() {
    byte[] r = new byte[256];
    byte[] g = new byte[256];
    byte[] b = new byte[256];
    for(int i=0; i<256; i++) {
       r[i]=(byte)i;
       g[i]=(byte)i;
       b[i]=(byte)i;
    }
    IndexColorModel defaultColorModel = new IndexColorModel(8, 256, r, g, b);
    return defaultColorModel;
}

public void findMinAndMax(short[] pixels, int width, int height) {
    int size = width*height;
    int value;
    min = 65535;
    max = 0;
    for (int i=0; i<size; i++) {
        value = pixels[i]&0xffff;
        if (value<min)
           min = value;
        if (value>max)
           max = value;
        }
}

If performance is important (ex. to display animation), I suggest to use:

javafx.embed.swing.SwingFXUtils.toFXImage(bufferedImage, null)

On my machine it is about 6 times faster than rendering image to a png then parsing that with JavaFX.

Update:
An even faster solution that avoids the intermediary BufferedImage is:

ByteBuffer bgraPixels = convertToBgra(rawPixels); // convert your byte[] array into a ByteBuffer in bgra format.
Image img = new WritableImage(new PixelBuffer<>(width, height, bgraImage, WritablePixelFormat.getByteBgraPreInstance()));

Good job! Thanks :D

convertToBgra

Hi,
Where did you get method: convertToBgra(rawPixels) ?

Thx
Chris

@ouaibsky I have created it like this. I'm using ByteBuffer input here instead of byte[], but that's basically just a wrapper around the array. I'm doing RGBA->BGRA conversion, depending on you input format, you may just have to wrap the byte array.

Also in some cases further optimization can by done by moving longs instead of bytes.