Create a set of image files from a byte matrix

Question

As I wrote in the title I would like to understand how to create some images from an array that contains bytes. This is what has been written so far

        BufferedImage arrayImage[] = new BufferedImage [depthV];
        int arrayIndex = 0;
        for (int z = 0; z < depthV; z++)
        {
            byte byteToImg[] = new byte [widthV*heightV];
            for (int x = 0; x < widthV; x++) 
            {
                for (int y = 0; y < heightV; y++) 
                {
                     byteToImg[x + y] = data3D[0][z][y][x];
                }
            }
            ByteArrayInputStream byteIn = new ByteArrayInputStream(byteToImg);
            BufferedImage finalImage= null;
            try {
                finalImage = ImageIO.read(byteIn);
            } catch (IOException e) {

                e.printStackTrace();
            }
            arrayImage[arrayIndex]=finalImage;
            arrayIndex++;
        }
        for (int i = 0; i < arrayImage.length; i++) 
        {
            File outputfile = new File("./Resources/tmp/image"+i+".jpg");
            try {
                ImageIO.write(arrayImage[i], "jpg", outputfile);
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }

The Java function ends with a java.lang.IllegalArgumentException: image == null! What is my error? How I can avoid this issue? Is there a better way to do this?

Answer 1

The SCIFIO library, bundled with ImageJ, can do this easily:

import io.scif.gui.AWTImageTools;
...
byte[] bytes = new byte[width * height];
...
boolean signed = false;
BufferedImage bi = AWTImageTools.makeImage(bytes, width, height, signed);

The source code for that method is here (which calls here, which calls here).

But actually you don't need to use BufferedImage at all if you use SCIFIO and/or ImageJ. See this tutorial for an example of how to write out image planes.

SCIFIO is available from the ImageJ Maven repository. The relevant pom.xml snippets are:

<repositories>
    <repository>
        <id>imagej.public</id>
        <url>http://maven.imagej.net/content/groups/public</url>
    </repository>
</repositories>
...
<dependency>
    <groupId>io.scif</groupId>
    <artifactId>scifio</artifactId>
    <version>0.22.0</version>
</dependency>