Develop Reference

How to convert a OutputStream object to a file object?

I need to convert an image file(large size to small size). So, I am decoding image file to bitmap image and then I compressed bitmap image. I need to save this bitmap into File object again. Can anyone help me?

first covert your bitmap to byte[] object by
Bitmap bmp; //your bitmap object
ByteArrayOutputStream stream = new ByteArrayOutputStream();
bmp.compress(Bitmap.CompressFormat.PNG, 100, stream);
byte[] byteArray = stream.toByteArray();
Then create a FileOutputStream Object and write the byte[] to the fileoutputstream
File yourOutputFile = new File("/the/path/to/your/file")
FileOutputStream fos = new FileOutputStream(yourOutputFile);
fos.write(byteArray);
fos.close();
return yourOutputFile;//this will be your output

Converting byte array to jpg image file throughing exception

Hi I have a byte array that I am converting to jpg image but that is giving exception as below please explain me wht is the problem with this.
ByteArrayInputStream bis = new ByteArrayInputStream(someByteArray);
Iterator<?> readers = ImageIO.getImageReadersByFormatName("jpg");
//ImageIO is a class containing static methods for locating ImageReaders
//and ImageWriters, and performing simple encoding and decoding.
ImageReader reader = (ImageReader) readers.next();
Object source = bis;
ImageInputStream iis = ImageIO.createImageInputStream(source);
reader.setInput(iis, true);
ImageReadParam param = reader.getDefaultReadParam();
BufferedImage image = reader.read(0, param);
//got an image file
BufferedImage bufferedImage = new BufferedImage(image.getWidth(null), image.getHeight(null), BufferedImage.TYPE_INT_RGB);
//bufferedImage is the RenderedImage to be written
Graphics2D g2 = bufferedImage.createGraphics();
g2.drawImage(image, null, null);
File imageFile = new File("D:\\newrose2.jpg");
ImageIO.write(bufferedImage, "jpg", imageFile);
Exception:
javax.imageio.IIOException: Invalid JPEG file structure: SOS before SOF
at com.sun.imageio.plugins.jpeg.JPEGImageReader.readImageHeader(Native Method)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.readNativeHeader(JPEGImageReader.java:550)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.readNativeHeader(JPEGImageReader.java:550)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.checkTablesOnly(JPEGImageReader.java:295)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.gotoImage(JPEGImageReader.java:427)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.readHeader(JPEGImageReader.java:543)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.readInternal(JPEGImageReader.java:986)
at com.sun.imageio.plugins.jpeg.JPEGImageReader.read(JPEGImageReader.java:966)
at Trnsport.writejpegfile(Trnsport.java:398)
at Trnsport.getData(Trnsport.java:107)
at Trnsport.run(Trnsport.java:63)
at java.lang.Thread.run(Thread.java:722)
Edit:
FileOutputStream fos = new FileOutputStream("image" + new Date().getTime() + ".jpg");
fos.write(someByteArray);
fos.close();

If your byte array already contains valid JPEG data, you do not need to invoke the JPEG reader or writer -- you can write the bytes to the file using ordinary file I/O.
If the byte array actually contains some format of raw pixel data, you will need to load it into a BufferedImage directly (such as via setRGB) and encode that as a JPEG.
The fact that you're getting an exception trying to decode it implies it is not JPEG data, but raw pixel data. Or, perhaps it is a different type of image altogether, or it has an image at some offset into the array instead of at the start the array, or it is not an image at all.

convert all images to PNG

I need a dynamic solution to convert a unknown image format to .png in java.
Will .getType() help me out here, it seems only to return numbers.
The converted image should later be stored in a folder, but I guess that is easly done in the
ImageIO.write().
It's just that with converting an unknown image format that I have no idea how to approach.

This peace of code should do the magic:
File file = new File("unknown.type.pic");
ByteArrayInputStream bais = new ByteArrayInputStream(FileUtils.readFileToByteArray(file);
BufferedImage image = ImageIO.read(bais);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write(image, "jpg", baos);
OutputStream outputStream = new FileOutputStream ("output.jpg");
baos.writeTo(outputStream);
Add missing try/catch/finally blocks.

bytes to Image Conversion in java

I am trying to convert Image to Byte Array and save it in database. Image to Byte Conversion and bytes to Image Conversion using ImageIO Method works completely fine before saving it into database. But when i retrieve bytes from Database ImageIO returns null.
FileInputStream fis = new FileInputStream(picturePath);
BufferedImage image = ImageIO.read(new File(picturePath));
BufferedImage img = Scalr.resize(image, Scalr.Mode.FIT_EXACT, 124, 133, Scalr.OP_ANTIALIAS);
ByteArrayOutputStream ByteStream = new ByteArrayOutputStream();
ImageIO.write(img, "jpg", ByteStream);
ByteStream.flush();
byte[] imageBytes = ByteStream.toByteArray();
ByteStream.close();
PersonImage = imageBytes;
ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(PersonImage);
BufferedImage ImageForBox = ImageIO.read((InputStream)byteArrayInputStream);
PersonImageBox.setIcon(new ImageIcon((Image)ImageForBox));
Above code is what I do before saving picture bytes in DB. I resize the Image then convert it into bytes and then convert other way around and show it in JLabel, it works fine. But when I retrieve bytes from database and use the same code i.e.
ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(PersonImage); // PersonImage are bytes from dB.
BufferedImage ImageForBox = ImageIO.read((InputStream)byteArrayInputStream);
PersonImageBox.setIcon(new ImageIcon((Image)ImageForBox));
In this case ImageIO returns null. Please help.

Java: BufferedImage to byte array and back

I see that a number of people have had a similar problem, however I'm yet to try find exactly what I'm looking for.
So, I have a method which reads an input image and converts it to a byte array:
File imgPath = new File(ImageName);
BufferedImage bufferedImage = ImageIO.read(imgPath);
WritableRaster raster = bufferedImage .getRaster();
DataBufferByte data = (DataBufferByte) raster.getDataBuffer();
What I now want to do is convert it back into a BufferedImage (I have an application for which I need this functionality). Note that "test" is the byte array.
BufferedImage img = ImageIO.read(new ByteArrayInputStream(test));
File outputfile = new File("src/image.jpg");
ImageIO.write(img,"jpg",outputfile);
However, this returns the following exception:
Exception in thread "main" java.lang.IllegalArgumentException: im == null!
This is because the BufferedImage img is null. I think this has something to do with the fact that in my original conversion from BufferedImage to byte array, information is changed/lost so that the data can no longer be recognised as a jpg.
Does anyone have any suggestions on how to solve this? Would be greatly appreciated.

This is recommended to convert to a byte array
ByteArrayOutputStream baos = new ByteArrayOutputStream();
ImageIO.write(img, "jpg", baos);
byte[] bytes = baos.toByteArray();

Note that calling close or flush will do nothing, you can see this for yourself by looking at their source/doc:
Closing a ByteArrayOutputStream has no effect.
The flush method of OutputStream does nothing.
Thus use something like this:
ByteArrayOutputStream baos = new ByteArrayOutputStream(THINK_ABOUT_SIZE_HINT);
boolean foundWriter = ImageIO.write(bufferedImage, "jpg", baos);
assert foundWriter; // Not sure about this... with jpg it may work but other formats ?
byte[] bytes = baos.toByteArray();
Here are a few links concerning the size hint:
Java: Memory efficient ByteArrayOutputStream
jpg bits per pixel
Of course always read the source code and docs of the version you are using, do not rely blindly on SO answers.