Develop Reference

Copying image and maintain orientation?

Edit
It turns out that the 2nd snippet is actually working but the images in question still show incorrectly in my IDE (IntelliJ IDEA) for some reason.
I am trying read an image, place a watermark and save it in a different folder and the below code does a good job, but it randomly orientates my images.
try {
final Image image = ImageIO.read(file);
int w = ((BufferedImage) image).getWidth();
int h = ((BufferedImage) image).getHeight();
final BufferedImage finalImage =
new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
//Graphics2D g = finalImage.createGraphics();
Graphics2D g = (Graphics2D) finalImage.getGraphics();
g.drawImage(image, 0, 0, null);
g.drawImage(watermark, 0, 0, null);
g.dispose();
File outputFile = new File("watermarked/" + folderName + "/" + file.getName());
outputFile.mkdirs();
ImageIO.write(finalImage, "jpg", outputFile);
} catch (IOException e) {
// TODO: notify client
e.printStackTrace();
}
After some reading I learned that ImageIO.read(...) does not maintain orientation or other "metadata" of the image it is processing. I also read about using the ImageReader to extract the metadata. According to the docs, using ImageReader.readall() should include the metadata in the returned IIOImage but I still end up with some of my images upside down. The below code demonstrates the copying without adding a watermark.
File out = new File("watermarked/" + folderName + "/" + file.getName());
out.getParentFile().mkdirs();
ImageInputStream input = ImageIO.createImageInputStream(file);
ImageOutputStream output = ImageIO.createImageOutputStream(out);
Iterator<ImageReader> readers = ImageIO.getImageReaders(input);
ImageReader reader = readers.next();
reader.setInput(input);
IIOImage image = reader.readAll(0, null);
// Should not be needed since readAll should already take care of it.
IIOMetadata metadata = reader.getImageMetadata(0);
image.setMetadata(metadata);
ImageWriter writer = ImageIO.getImageWriter(reader);
writer.setOutput(output);
writer.write(image);
System.out.println(writer.canReplaceImageMetadata(0)); // Returns false
writer.replaceImageMetadata(0, metadata); // Results in a "Unsupported write variant" error.
Both code snippets reside in a method that get passed a folderName as a string and the actual image file.
Edit
The above snippet works and the issue is something else. In my windows folder all my images made with a Galaxy S8 show in the correct orientation. But when I copy them to my project and open them in IntelliJ IDEA some are oriented differently. So I added sanselan as a dependency to get more insight in the meta data of the images and the images that get a different orientation in the IDE do indeed show a different orientation in the metadata. But why aren't they oriented like that in the windows folder, am I missing a metadata field or is windows storing additional data somewhere outside the image metadata?

How to save indexed color PNG in java

How to save image in java as java.awt.image.IndexColorModel PNG? I'm loading indexed color png with ImageIO, manipulate it with Catalino library which unfortunately converts the color space to java.awt.image.DirectColorModel.
Now I want to save the result in the exactly same format as the original image. I tried the following snippet of code.
private static void testIndexedColor() throws IOException {
FastBitmap input = new FastBitmap("test.png");
BufferedImage bi = new BufferedImage(input.getWidth(), input.getHeight(), BufferedImage.TYPE_BYTE_INDEXED);
bi.getGraphics().drawImage(input.toBufferedImage(), 0, 0, null);
ImageIO.write(bi, "PNG", new File("test_result.png"));
}
But in the result weird light gray pixel artifacts appeared in the white background, and PPI decreased . How to correctly convert back to indexed color mode without quality loss and distortion?

Assuming I'm correct about the Catalano framework, you should be able to re-write your methods as this:
private static void testIndexedColor() throws IOException {
BufferedImage bi = ImageIO.read(new File("test.png"));
FastBitmap input = new FastBitmap(bi);
Graphics2D g = bi.createGraphics();
try {
g.drawImage(input.toBufferedImage(), 0, 0, null);
}
finally {
g.dispose(); // Good practice ;-)
}
ImageIO.write(bi, "PNG", new File("test_result.png"));
}
At least you should get away with the fixed palette and the artifacts.
However, this will likely still modify the PPI (but this won't affect the pixels). And even in some cases the image might be written back as a non-palette PNG.
Update: It seems the PNGImageWriter (through the PNGMetadata) actually re-writes an IndexColorModel containing a perfect grayscale, to a grayscale PNG by default. This is normally a good idea, as you reduce file size by not writing the PLTE chunk. You should be able to get around this, by passing the metadata from the original, along with the image pixel data, to instruct the writer to keep the IndexColorModel (ie. write PLTE chunk):
private static void testIndexedColor() throws IOException {
File in = new File("test.png");
File out new File("test_result.png");
try (ImageInputStream input = ImageIO.createImageInputStream(in);
ImageOutputStream output = ImageIO.createImageOutputStream(out)) {
ImageReader reader = ImageIO.getImageReaders(input).next(); // Will fail if no reader
reader.setInput(input);
ImageWriter writer = ImageIO.getImageWriter(reader); // Will obtain a writer that understands the metadata from the reader
writer.setOutput(output); // Will fail if no writer
// Now, the important part, we'll read the pixel AND metadata all in one go
IIOImage image = reader.readAll(0, null); // PNGs only have a single image, so index 0 is safe
// You can now access and modify the image data using:
BufferedImage bi = (BufferedImage) image.getRenderedImage();
FastBitmap fb = new FastBitmap(bi);
// ...do stuff...
Graphics2D g = bi.createGraphics();
try {
g.drawImage(fb.toBufferedImage(), 0, 0, null);
}
finally {
g.dispose();
}
// Write pixel and metadata back
writer.write(null, image, writer.getDefaultWriteParam());
}
}
This should (as a bonus) also keep your PPI as-is.
PS: For production code, you also want to dispose() of the reader and writer above, but I left it out to keep focus and avoid further discussion on try/finally. ;-)

Convert PNG to JPEG, Using Compression Quality, Why Inverted colors?

I have low information about the image files.
To be able to convert PNG to JPEG in Java, at first I have used below code part to convert PNG to JPEG: inverted
Code Part 1)
BufferedImage newBufferedImage = new BufferedImage(bufferedImageFile.getWidth(), bufferedImageFile.getHeight(),
BufferedImage.TYPE_INT_RGB);
newBufferedImage.createGraphics().drawImage(bufferedImageFile, 0, 0, Color.WHITE, null);
File retTempFile = MakeupFileUtil.createTempFile(fileName);
ImageIO.write(newBufferedImage, "jpg", retTempFile);
return retTempFile;
This accomplishes the task very well but the output quality is lower than the original PNG image quality(let's say PNG quality is 100 but JPEG quality is 75)
Then, from this answer, I tried below code part which uses "Compression Quality":
Code Part 2)
JPEGImageWriteParam jpegParams = new JPEGImageWriteParam(null);
jpegParams.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
jpegParams.setCompressionQuality(1f);
final ImageWriter writer = ImageIO.getImageWritersByFormatName("jpg").next();
writer.setOutput(new FileImageOutputStream(jpegFile));
writer.write(null, new IIOImage(bufferedImageFile, null, null), jpegParams);
But this time, converted JPEG file got inverted colors.
Source Image (PNG):
Image After Code Part 2 (JPEG):
Why is this happening?

Try and write newBufferedImage and not bufferedImageFile on "Code part 2".
So change this line to be:
writer.write(null, new IIOImage(newBufferedImage, null, null), jpegParams);
If you try and write a PNG image in JPEG format your going to end up with weird results.

PDFBox draw black image from BufferedImage

I try to draw an image from a bufferedImage into a PDF using PDFBox but fails, and I get black images and Acrobat Reader warns whith errors like "Out of memory" (but PDF is display).
I use a bufferedImage because I need to draw a JavaFX Image object (with came from call to Funciones.crearImagenDesdeTexto(), is a function which converts a text into an Image) into PDF. Rest of images works well without using bufferedimage.
PDPixelMap img = null;
BufferedImage bi;
try {
//If item has id, I try to get image with that id (image it's shows OK on PDF)
img = new PDPixelMap(documento, read(getClass().getResourceAsStream("/com/img/" + item.getId() + ".png")));
}
catch (Exception e) {
//If item has not id or fails load image, I create image on the fly (which contains item name. This not work on PDF, shows black images)
bi = new BufferedImage(alto, ancho, BufferedImage.TYPE_INT_ARGB);
bi.createGraphics().drawImage(SwingFXUtils.fromFXImage(Funciones.crearImagenDesdeTexto(item.getNombre()), null), ancho, alto, null);
img = new PDPixelMap(documento, bi);
}
finally {
contenedor.drawXObject(img, x, y, alto, ancho);
}
NOTE: crearImagenDesdeTexto() returns a JavaFX Image Object that is create on the fly (I try this function in other parts of the program and works well, function is take from other stackOverflow response).

Your code is confusing, you have three "new PDJpeg" and one of them is in a catch (which should just handle the error). And what does "read()" do? Does it pass a stream or a BufferedImage? If it is a stream, then it is wrong, because PDJpeg is for JPEGs, not for PNG.
The second one
img = new PDJpeg(documento, (getClass().getResourceAsStream("/com/img/" + Byte.toString(item.getId()) + ".png")));
is definitively wrong for the same reason: PDJPeg is not for PNG files / streams.
If you want to create an image from a PNG file / stream, use PDPixelMap.
It is possible to create a PDJpeg object from a BufferedImage, but this is recommended only if the image wasn't encoded before. Because if you would read a BufferedImage from a JPEG, and then use PDJPeg for this, you'll have a slight loss of quality as the image is decoded and encoded again (JPEG is a "lossy" compression format).
If my advice doesn't help, please upload the JPEG file and the PDF somewhere.
Also make sure that you're using the latest version, which is 1.8.7.
Update after comments:
the parameters to createGraphics.drawImage() should be 0, 0 and not width, height. The two parameters are a location, not a size.

Finally, I find a solution (thanks also to Tilman Hausherr):
private void dibujarImagen(Item i, int x, int y, int alto, int ancho) throws IOException {
PDPixelMap img = null;
try {
img = new PDPixelMap(documento, read(getClass().getResourceAsStream("/com/img/" + i.getId() + ".png")));
}
catch (IllegalArgumentException e) {
img = new PDPixelMap(documento, SwingFXUtils.fromFXImage(Funciones.crearImagenDesdeTexto(i.getNombre()),null));
}
finally {
contenedor.drawXObject(img, x, y, alto, ancho);
}
}

BufferedImage to File with black background

I'm trying to save a BufferedImage (came from byte[]) to a File, but it's producing a black background without the image. I'm using the photoCam from primefaces.
This is my ManagedBean method:
public void webcamCapture(CaptureEvent captureEvent) {
try {
byte[] data = captureEvent.getData();
InputStream in = new ByteArrayInputStream(data);
BufferedImage fotoBuffered = ImageIO.read(in);
String idImagem = ImagemHelper.getInstance().salvarImagemFromImageObject(fotoBuffered);
paciente.getPessoaFisica().setFoto(idImagem);
} catch (Exception e) {
addErrorMessage("Erro ao capturar imagem da webcam");
FacesContext.getCurrentInstance().validationFailed();
}
}
The method "salvarImagemFromImageObject" simple make a "ImageIO.write(image,"jpg",destFile)" to save a file, but this file don't have nothing, just a black background.

Primefaces PhotoCam component renders PNG images. PNG format is by design. If you want to work with another file format, you'll need to post-process the PNG image rendered by the PF component.
Refactor your salvarImagemFromImageObject function with a .png destFile:
ImageIO.write(fotoBuffered, "png", destFile);
EDIT
Writes the resulting png data to jpeg format:
//Converts PNG image to plain RGB format
BufferedImage newBufferedImage = new BufferedImage(fotoBuffered.getWidth(), fotoBuffered.getHeight(), BufferedImage.TYPE_INT_RGB);
newBufferedImage.createGraphics().drawImage(fotoBuffered , 0, 0, Color.WHITE, null);
//Then, writes to jpeg file
ImageIO.write(newBufferedImage, "jpg", destFile);