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How to save 16bit depth Image to file in Arcore (java)

I want to save the depth info from the arcore to the storage.
Here is the example from the developer guide.
public int getMillimetersDepth(Image depthImage, int x, int y) {
// The depth image has a single plane, which stores depth for each
// pixel as 16-bit unsigned integers.
Image.Plane plane = depthImage.getPlanes()[0];
int byteIndex = x * plane.getPixelStride() + y * plane.getRowStride();
ByteBuffer buffer = plane.getBuffer().order(ByteOrder.nativeOrder());
short depthSample = buffer.getShort(byteIndex);
return depthSample;
}
So I want to save this bytebuffer into a local file, but my output txt file is not readable. How could I fix this?
Here is what I have
Image depthImage = frame.acquireDepthImage();
Image.Plane plane = depthImage.getPlanes()[0];
int format = depthImage.getFormat();
ByteBuffer buffer = plane.getBuffer().order(ByteOrder.nativeOrder());
byte[] data = new byte[buffer.remaining()];
buffer.get(data);
File mypath=new File(super.getExternalFilesDir("depDir"),Long.toString(lastPointCloudTimestamp)+".txt");
FileChannel fc = new FileOutputStream(mypath).getChannel();
fc.write(buffer);
fc.close();
depthImage.close();
I tried to decode them with
String s = new String(data, "UTF-8");
System.out.println(StandardCharsets.UTF-8.decode(buffer).toString());
but the output is still strange like this
.03579:<=>#ABCDFGHJKMNOPRQSUWY]_b

In order to obtain the depth data provided by the ARCore session, you need to write bytes into your local file. A Buffer object is a container, it countains a finite sequence of elements of a specific primitive type (here bytes for a ByteBuffer). So what you need to write inside your file is your data variable that corresponds to the information previously stored in the buffer (according to buffer.get(data)).
It works fine for me, I managed to draw the provided depth map within a python code (but the idea behind the following code can be easily adapted to a java code):
depthData = np.fromfile('depthdata.txt', dtype = np.uint16)
H = 120
W = 160
def extractDepth(x):
depthConfidence = (x >> 13) & 0x7
if (depthConfidence > 6): return 0
return x & 0x1FFF
depthMap = np.array([extractDepth(x) for x in depthData]).reshape(H,W)
depthMap = cv.rotate(depthMap, cv.ROTATE_90_CLOCKWISE)
For further details, read the information concerning the format of the depthmap (DEPTH16) here: https://developer.android.com/reference/android/graphics/ImageFormat#DEPTH16
You must also be aware that the depthmap resolution is set to 160x120 pixels and is oriented according to a landscape format.
Make also sure to surround your code by a try/catch code bloc in case of a IOException error.

Convert GIF images to PNG format, 32 bits depth

Here is a solution to convert GIF images to PNG format. The problem is that the generated PNG images are in 8 bits depth (in my case at least).
Is there a way to force them to be in 32 bits depth? The best would be using the javax.imageio.ImageIO library.

Just convert the BufferedImage, redrawing a copy with the desidered colour model. Not extremely efficient, but practical:
File input = new File("/tmp/input.gif");
File output = new File("/tmp/output.png");
BufferedImage im1 = ImageIO.read( input );
BufferedImage im2 = new BufferedImage(im1.getWidth(), im1.getHeight(),
BufferedImage.TYPE_4BYTE_ABGR);
im2.getGraphics().drawImage(im1, 0, 0, null);
ImageIO.write(im2 , "png", output);

How to deal with the color profile while reading image using java

I find that while reading images(JPEG) using Java, the lots of pixels' RGB values are different with those in photoshop, the RGB values got by JIMI are also different with ImageIO, how can I get the RGB values exactly the same with photoshop in java ? thanks!
This is how I read images by:
1.ImageIO
BufferedImage test = ImageIO.read(file);
2.Jimi
JimiReader createJimiReader = Jimi.createJimiReader(new FileInputStream(filename));
JimiRasterImage rasterImage = createJimiReader.getRasterImage();
3.JAI
FileSeekableStream st = new FileSeekableStream(filename);
BufferedImage asBufferedImage = JAI.create("stream", st).getAsBufferedImage();

How to combine two or many tiff image files in to one multipage tiff image in JAVA

I have 5 single page tiff images.
I want to combine all these 5 tiff images in to one multipage tiff image.
I am using Java Advanced Imaging API.
I have read the JAI API documentation and tutorials given by SUN.
I am new to JAI. I know the basic core java.
I dont understand those documentation and turorial by SUN.
So friends Please tell me how to combine 5 tiff image file in to one multipage tiff image.
Please give me some guidence on above topic.
I have been searching internet for above topic but not getting any single clue.

I hope you have the computer memory to do this. TIFF image files are large.
You're correct in that you need to use the Java Advanced Imaging (JAI) API to do this.
First, you have to convert the TIFF images to a java.awt.image.BufferedImage. Here's some code that will probably work. I haven't tested this code.
BufferedImage image[] = new BufferedImage[numImages];
for (int i = 0; i < numImages; i++) {
SeekableStream ss = new FileSeekableStream(input_dir + file[i]);
ImageDecoder decoder = ImageCodec.createImageDecoder("tiff", ss, null);
PlanarImage op = new NullOpImage(decoder.decodeAsRenderedImage(0), null, null, OpImage.OP_IO_BOUND);
image[i] = op.getAsBufferedImage();
}
Then, you convert the BufferedImage array back into a multiple TIFF image. I haven't tested this code either.
TIFFEncodeParam params = new TIFFEncodeParam();
OutputStream out = new FileOutputStream(output_dir + image_name + ".tif");
ImageEncoder encoder = ImageCodec.createImageEncoder("tiff", out, params);
Vector vector = new Vector();
for (int i = 0; i < numImages; i++) {
vector.add(image[i]);
}
params.setExtraImages(vector.listIterator(1)); // this may need a check to avoid IndexOutOfBoundsException when vector is empty
encoder.encode(image[0]);
out.close();

Convert PNG to bitonal TIFF

-Edit-
FYI.. I am converting b&w documents scanned in as greyscale or color.
1)The first solution worked, it just reversed black & white (black background, white text). It also took nearly 10 minutes.
2)The JAI solution in the 2nd answer didn't work for me. I tried it before posting here.
Has anyone worked with other libraries free or pay that handle image manipulation well?
-Original-
I am trying to convert an PNG to a bitonal TIFF using Java ImageIO. Has anyone had any luck doing this? I have got it to convert from PNG to TIFF. I am not sure if I need to convert the BufferedImage (PNG) that I read in or convert on the TIFF as I write it. I have searched and searched but nothing seems to work? Does anyone have an suggestions where to look?
Here is the code that converts...
public static void test() throws IOException {
String fileName = "4848970_1";
// String fileName = "color";
String inFileType = ".PNG";
String outFileType = ".TIFF";
File fInputFile = new File("I:/HPF/UU/" + fileName + inFileType);
InputStream fis = new BufferedInputStream(new FileInputStream(fInputFile));
ImageReaderSpi spi = new PNGImageReaderSpi();
ImageReader reader = spi.createReaderInstance();
ImageInputStream iis = ImageIO.createImageInputStream(fis);
reader.setInput(iis, true);
BufferedImage bi = reader.read(0);
int[] xi = bi.getSampleModel().getSampleSize();
for (int i : xi) {
System.out.println("bitsize " + i);
}
ImageWriterSpi tiffspi = new TIFFImageWriterSpi();
TIFFImageWriter writer = (TIFFImageWriter) tiffspi.createWriterInstance();
// TIFFImageWriteParam param = (TIFFImageWriteParam) writer.getDefaultWriteParam();
TIFFImageWriteParam param = new TIFFImageWriteParam(Locale.US);
String[] strings = param.getCompressionTypes();
for (String string : strings) {
System.out.println(string);
}
param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
param.setCompressionType("LZW");
File fOutputFile = new File("I:\\HPF\\UU\\" + fileName + outFileType);
OutputStream fos = new BufferedOutputStream(new FileOutputStream(fOutputFile));
ImageOutputStream ios = ImageIO.createImageOutputStream(fos);
writer.setOutput(ios);
writer.write(null, new IIOImage(bi, null, null), param);
ios.flush();
writer.dispose();
ios.close();
}
I have tried changing the compression to type "CCITT T.6" as that appears to be what I want, but I get an error " Bits per sample must be 1 for T6 compression! " Any suggestion would be appreciated.

Most likely, you want something like this to convert to 1 bit before you save to TIFF with CCITT compression.
To expound a little bit - be aware that converting from other bit depths to 1 bit is non-trivial. You are doing a data reduction operation and there are dozens of domain specific solutions which vary greatly in output quality (blind threshold, adaptive threshold, dithering, local threshold, global threshold and so on). None of them are particularly good at all image types (adaptive threshold is pretty good for documents, but lousy for photographs, for example).

As plinth said, you have to do the conversion, Java won't do it magically for you...
If the PNG image is already black & white (as it seems, looking at your comment), using a threshold is probably the best solution.
Somebody seems to have the same problem: HELP: how to compress the tiff. A solution is given on the thread (untested!).