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Cannot cast DataBufferInt to DataBufferByte on specific picture(s)

I am trying to threshold my images, but some of them have problem with casting to DataBufferByte. I post here two types of pictures - the first (the test1.jpg is good and can be casted to DataBufferByte), the second (test2.jpg throwing an exception).
Images:
Here is my code:
public static void main(String[] args) throws IOException {
System.loadLibrary( Core.NATIVE_LIBRARY_NAME );
BufferedImage bufferedImage = ImageIO.read(new File("/test/test2.jpg"));
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
ImageIO.write(bufferedImage, "jpg", byteArrayOutputStream);
byte[] input = byteArrayOutputStream.toByteArray();
InputStream is = new ByteArrayInputStream(input);
bufferedImage = ImageIO.read(is);
byte[] data = ((DataBufferByte) bufferedImage.getRaster().getDataBuffer()).getData();
Mat mat = new Mat(bufferedImage.getHeight(), bufferedImage.getWidth(), CvType.CV_8UC3);
mat.put(0, 0, data);
Mat mat1 = new Mat(bufferedImage.getHeight(),bufferedImage.getWidth(),CvType.CV_8UC1);
Imgproc.cvtColor(mat, mat1, Imgproc.COLOR_RGB2GRAY);
byte[] data1 = new byte[mat1.rows() * mat1.cols() * (int)(mat1.elemSize())];
mat1.get(0, 0, data1);
Mat dst = new Mat();
Imgproc.adaptiveThreshold(mat1, dst, 255, Imgproc.ADAPTIVE_THRESH_MEAN_C, Imgproc.THRESH_BINARY, 11, 15);
MatOfByte matOfByte = new MatOfByte();
Imgcodecs.imencode(".jpg", dst, matOfByte);
ByteArrayInputStream inputStream = new ByteArrayInputStream(matOfByte.toArray());
bufferedImage = ImageIO.read(inputStream);
ImageIO.write(bufferedImage, "jpg", new File("/test_output/test2.jpg"));
}
The output for test1.jpg image is correct:
But the second image throwing an exception
Exception in thread "main" java.lang.ClassCastException:
java.awt.image.DataBufferInt cannot be cast to
java.awt.image.DataBufferByte
at line
byte[] data = ((DataBufferByte) bufferedImage.getRaster().getDataBuffer()).getData();
What is the problem ? Why the one .jpg image is converted without problems but second throwing an exception?

Both are not of the same format. One using 8-bit for color representation and the other 3x8-bit (so 4 bytes, with padding or transparency)?
Looking at it give:
image1 : JPEG image data, JFIF standard 1.01, aspect ratio, density 1x1, segment length 16, baseline, precision 8, 449x361, components 3
image2 : PNG image data, 617 x 353, 8-bit/color RGBA, non-interlaced
You may use the getDataType() method on the buffer to get the size of the color representation.

How can I convert fingerprint jpg to WSQ use JMRTD WSQEncoder.encode

I'm using JMRTD library (https://github.com/E3V3A/JMRTD/tree/master/wsq_imageio) to encode jpg to WSQ. I set Bitmap by manually instead of decode from WSQ file.
BufferedImage bufferedImage = ImageIO.read(fileInput.getInputStream());
WritableRaster raster = bufferedImage.getRaster();
DataBufferByte data = (DataBufferByte) raster.getDataBuffer();
Bitmap bitmap = new Bitmap(data.getData(), width, height, ppi, depth, lossyflag);
OutputStream outputStream = new FileOutputStream("c.wsq");
String commentText = "";
WSQEncoder.encode(outputStream, bitmap, bitrate, commentText);
Here is my original picture jpg:
And below is my result WSQ file:
How can I fix it. Many thanks!

I resolved this problem, here is my code for convert jpg, png to wsq format:
// 1. Read files to BufferedImage for get width, height. Convert Bit depth to 8-gray
BufferedImage bufferedImage = ImageIO.read(fileInput.getInputStream());
// 2. Convert Bit depth to 8-gray (This is what i had to do to solve this problem)
BufferedImage img = new BufferedImage(bufferedImage.getWidth(), bufferedImage.getHeight(), BufferedImage.TYPE_BYTE_GRAY);
Graphics g = img.getGraphics();
g.drawImage(bufferedImage, 0, 0, null);
g.dispose();
// 3. Convert file format to byte[] and convert to type Bitmap
WritableRaster raster = img.getRaster();
DataBufferByte data = (DataBufferByte) raster.getDataBuffer();
Bitmap bitmap = new Bitmap(data.getData(), bufferedImage.getWidth(), bufferedImage.getHeight(), 500, 8, 1);
// 4. Create file wsq
OutputStream outputStream = new FileOutputStream("c.wsq");
double bitrate = 0.75f;
String commentText = "";
// 5. Write the input file to the generated wsq file
WSQEncoder.encode(outputStream, bitmap, bitrate, commentText);
outputStream.close();
Hope help you # Dan Ortega

getting a bufferedImage from a bytearray

I am trying to get back a bufferedImage from array of bytes, but I am getting an error saying bufferedimage is null. I actually tried several ways, everything ended up in the same way. Here goes my code:
1)
byte[] arr = Base64.decode(base64String);
BufferedImage bImageFromConvert =ImageIO.read(new ByteArrayInputStream(arr));
2)
InputStream in = new ByteArrayInputStream(arr);
BufferedImage bImageFromConvert = ImageIO.read(in);
I am pretty sure my byte array contains data and I think ImageIO.read() is where my code goes wrong.

The error is in your BufferedImage to Base64 encode method as you have posted in the comments.
You are never writing the BufferedImage to the ByteArrayOutputStream. Therefore the Base64 string is empty, and reading the empty string produces a null BufferedImage.
You should use this code to encode your image:
BufferedImage originalImage = ImageIO.read(new File("G:\\a.jpg"));
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write( originalImage, "jpg", baos );
String base64String=Base64.encode(baos.toByteArray());
To decode the image use this code:
byte[] arr = Base64.decode(base64String);
BufferedImage bImageFromConvert =ImageIO.read(new ByteArrayInputStream(arr));
System.out.println(bImageFromConvert.getWidth());

Try this code.Maybe it works. It worked for me.
byte[] aByteArray = {};
int width = ;
int height = ;
DataBuffer buffer = new DataBufferByte(aByteArray, aByteArray.length);
WritableRaster raster = Raster.createInterleavedRaster(buffer, width, height, 3 * width, 3, new int[] {0, 1, 2}, (Point)null);
ColorModel cm = new ComponentColorModel(ColorModel.getRGBdefault().getColorSpace(), false, true, Transparency.OPAQUE, DataBuffer.TYPE_BYTE);
BufferedImage image = new BufferedImage(cm, raster, true, null);
Just add the byte, width and height to code and customize it.

Java ARGB to JPG

How can I save BufferedImage with TYPE_INT_ARGB to jpg?
Program generates me that image:
And it's OK, but when I save it in that way:
ByteArrayOutputStream byteStream = new ByteArrayOutputStream();
BufferedOutputStream bos = new BufferedOutputStream(byteStream);
try {
ImageIO.write(buffImg, "jpg", bos);
// argb
byteStream.flush();
byte[] newImage = byteStream.toByteArray();
OutputStream out = new BufferedOutputStream(new FileOutputStream("D:\\test.jpg"));
out.write(newImage);
out.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
The result is:
Understand that this is due to the alpha layer, but don't know how to fix it. Png format does not suit me, need jpg.

OK!
I've solved it.
Everything was pretty easy. Don't know is it a good decision and how fast it is. I have not found any other.
So.. everything we need is define new BufferedImage.
BufferedImage buffImg = new BufferedImage(getWidth(), getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = buffImg.createGraphics();
// ... other code we need
BufferedImage img= new BufferedImage(buffImg.getWidth(), buffImg.getHeight(), BufferedImage.TYPE_INT_RGB);
Graphics2D g2d = img.createGraphics();
g2d.drawImage(buffImg, 0, 0, null);
g2d.dispose();
If there any ideas to improve this method, please, your welcome.

Images having 4 color channels should not be written to a jpeg file. We can convert between ARGB and RGB images without duplicating pixel values. This comes in handy for large images. An example:
int a = 10_000;
BufferedImage im = new BufferedImage(a, a, BufferedImage.TYPE_INT_ARGB);
Graphics2D g = im.createGraphics();
g.setColor(Color.RED);
g.fillRect(a/10, a/10, a/5, a*8/10);
g.setColor(Color.GREEN);
g.fillRect(a*4/10, a/10, a/5, a*8/10);
g.setColor(Color.BLUE);
g.fillRect(a*7/10, a/10, a/5, a*8/10);
//preserve transparency in a png file
ImageIO.write(im, "png", new File("d:/rgba.png"));
//pitfall: in a jpeg file 4 channels will be interpreted as CMYK... this is no good
ImageIO.write(im, "jpg", new File("d:/nonsense.jpg"));
//we need a 3-channel BufferedImage to write an RGB-colored jpeg file
//we can make up a new image referencing part of the existing raster
WritableRaster ras = im.getRaster().createWritableChild(0, 0, a, a, 0, 0, new int[] {0, 1, 2}); //0=r, 1=g, 2=b, 3=alpha
ColorModel cm = new BufferedImage(1, 1, BufferedImage.TYPE_INT_RGB).getColorModel(); //we need a proper ColorModel
BufferedImage imRGB = new BufferedImage(cm, ras, cm.isAlphaPremultiplied(), null);
//this image we can encode to jpeg format
ImageIO.write(imRGB, "jpg", new File("d:/rgb1.jpg"));

How to convert PNG to jpeg in grails/java

I have a png file and tried to convert it to jpeg. But the resulting image has wrong colors with very big areas of pink. This is my code:
BufferedImage image = null
BufferedImage imageRGB = null
image = ImageIO.read(new ByteArrayInputStream(imageBytesPng))
imageRGB = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_RGB)
imageRGB.setData(image.getData())
ByteArrayOutputStream baos=new ByteArrayOutputStream()
ImageIO.write(imageRGB, "jpeg", baos)
baos.flush()
def outImage = baos.toByteArray()
baos.close()
return outImage
What can I change to make the image colors apear as in the png file?

InputStream pngInputStream = ...
OutputStream jpgOutputStream = ...
BufferedImage image = ImageIO.read(pngInputStream));
ImageIO.write(image, "jpeg", jpgOutputStream);

Try this all the best..
import javax.media.jai.*;
public class jai_png_jpg
{
public static void main(String[] args)throws Exception
{
String filename="input_png.png";
//Read input PNG as a PlanarImage file
PlanarImage inputfile = JAI.create("fileload", filename);
//write output in JPG Format
JAI.create("filestore",inputfile,"jai_jpg_output.jpg","JPEG"); } }