I'm trying to use the PictureService in Gluon Mobile to get a profile picture that can be stored in a MySQL table (Blob). What is the best way to get the byte array (and if possible the base64 encoded string) from the returned image object of the service? I tried SwingFXUtils, but it caused the app to crash on my Android. Thus, I am not sure the SwingFXUtils is supported.
Services.get(PicturesService.class).ifPresent(service -> {
service.takePhoto(false).ifPresent(image -> {
try {
byte[] imageStream = PictureFactory.convertToByteArray(image);
//String base64String = Base64.getEncoder().encodeToString(imageStream);
//this.picModel.setByteArray(imageStream);
//this.picModel.setBase64Str(base64String);
//this.picModel.setPatientId(User.patient.getPatientId());
av.setImage(image); //Avatar
av.setRotate(-90);
if (this.imageBox.getChildren().size() < 3) {
this.imageBox.getChildren().add(0, av);
}
} catch (Exception ex) {
Logger.getLogger(PictureFactory.class.getName()).log(Level.SEVERE, null, ex);
}
});
});
Byte Array Conversion Code:
public static byte[] convertToByteArray(Image img) throws IOException {
BufferedImage byteImg = SwingFXUtils.fromFXImage(img, null);
ByteArrayOutputStream stream = new ByteArrayOutputStream();
ImageIO.write(byteImg, "png", stream);
byte[] result = stream.toByteArray();
stream.close();
return result;
}
A completely unrelated issue which I am also experiencing is that the image is rotated 90 degrees clockwise when taking it in portrait mode. Any way to fix this? I'm hoping it can be fixed in the image itself that gets sent to the database instead of just rotating the imageview.
Related
UPDATE: The initial question has been answered as to why the crashes happen but the lingering problem remains of why is the 'OnImageAvailable' callback called so may times? When it is called, I want to do stuff with the image, but whatever method I run at that time is called many times. Is this the wrong place to be using the resulting image?
I am using the sample code found here for a Xamarin Android implementation of the Android Camera2 API. My issue is that when the capture button is pressed a single time, the OnCameraAvalibleListener's OnImageAvailable callback gets called multiple times.
This is causing a problem because the image from AcquireNextImage needs to be closed before another can be used, but close is not called until the Run method of the ImageSaver class as seen below.
This causes these 2 errors:
Unable to acquire a buffer item, very likely client tried to acquire
more than maxImages buffers
AND
maxImages (2) has already been acquired, call #close before acquiring
more.
The max image is set to 2 by default, but setting it to 1 does not help. How do I prevent the callback from being called twice?
public void OnImageAvailable(ImageReader reader)
{
var image = reader.AcquireNextImage();
owner.mBackgroundHandler.Post(new ImageSaver(image, file));
}
// Saves a JPEG {#link Image} into the specified {#link File}.
private class ImageSaver : Java.Lang.Object, IRunnable
{
// The JPEG image
private Image mImage;
// The file we save the image into.
private File mFile;
public ImageSaver(Image image, File file)
{
if (image == null)
throw new System.ArgumentNullException("image");
if (file == null)
throw new System.ArgumentNullException("file");
mImage = image;
mFile = file;
}
public void Run()
{
ByteBuffer buffer = mImage.GetPlanes()[0].Buffer;
byte[] bytes = new byte[buffer.Remaining()];
buffer.Get(bytes);
using (var output = new FileOutputStream(mFile))
{
try
{
output.Write(bytes);
}
catch (IOException e)
{
e.PrintStackTrace();
}
finally
{
mImage.Close();
}
}
}
}
The method OnImageAvailable can be called again as soon as you leave it if there is another picture in the pipeline.
I would recommend calling Close in the same method you are calling AcquireNextImage. So, if you choose to get the image directly from that callback, then you have to call Close in there as well.
One solution involved grabbing the image in that method and close it right away.
public void OnImageAvailable(ImageReader reader)
{
var image = reader.AcquireNextImage();
try
{
ByteBuffer buffer = mImage.GetPlanes()[0].Buffer;
byte[] bytes = new byte[buffer.Remaining()];
buffer.Get(bytes);
// I am not sure where you get the file instance but it is not important.
owner.mBackgroundHandler.Post(new ImageSaver(bytes, file));
}
finally
{
image.Close();
}
}
The ImageSaver would be modified to accept the byte array as first parameter in the constructor:
public ImageSaver(byte[] bytes, File file)
{
if (bytes == null)
throw new System.ArgumentNullException("bytes");
if (file == null)
throw new System.ArgumentNullException("file");
mBytes = bytes;
mFile = file;
}
The major downside of this solution is the risk of putting a lot of pressure on the memory as you basically save the images in memory until they are processed, one after another.
Another solution consists in acquiring the image on the background thread instead.
public void OnImageAvailable(ImageReader reader)
{
// Again, I am not sure where you get the file instance but it is not important.
owner.mBackgroundHandler.Post(new ImageSaver(reader, file));
}
This solution is less intensive on the memory; but you might have to increase the maximum number of images from 2 to something higher depending on your needs. Again, the ImageSaver's constructor needs to be modified to accept an ImageReader as a parameter:
public ImageSaver(ImageReader imageReader, File file)
{
if (imageReader == null)
throw new System.ArgumentNullException("imageReader");
if (file == null)
throw new System.ArgumentNullException("file");
mImageReader = imageReader;
mFile = file;
}
Now the Run method would have the responsibility of acquiring and releasing the Image:
public void Run()
{
Image image = mImageReader.AcquireNextImage();
try
{
ByteBuffer buffer = image.GetPlanes()[0].Buffer;
byte[] bytes = new byte[buffer.Remaining()];
buffer.Get(bytes);
using (var output = new FileOutputStream(mFile))
{
try
{
output.Write(bytes);
}
catch (IOException e)
{
e.PrintStackTrace();
}
}
}
finally
{
image?.Close();
}
}
I too facing this issue for longer time and tried implementing #kzrytof's solution but didn't helped well as expected but found the way to get the onImageAvailable to execute once.,
Scenario: When the image is available then the onImageAvailable method is called right?
so, What I did is after closing the image using image.close(); I called the imagereader.setonImageAvailableListener() and made the listener = null. this way I stopped the execution for second time.,
I know, that your question is for xamarin and my below code is in native android java but the method and functionalities are same, so try once:
#Override
public void onImageAvailable(ImageReader reader) {
final Image image=imageReader.acquireLatestImage();
try {
if (image != null) {
Image.Plane[] planes = image.getPlanes();
ByteBuffer buffer = planes[0].getBuffer();
int pixelStride = planes[0].getPixelStride();
int rowStride = planes[0].getRowStride();
int rowPadding = rowStride - pixelStride * width;
int bitmapWidth = width + rowPadding / pixelStride;
if (latestBitmap == null ||
latestBitmap.getWidth() != bitmapWidth ||
latestBitmap.getHeight() != height) {
if (latestBitmap != null) {
latestBitmap.recycle();
}
}
latestBitmap.copyPixelsFromBuffer(buffer);
}
}
catch(Exception e){
}
finally{
image.close();
imageReader.setOnImageAvailableListener(null, svc.getHandler());
}
// next steps to save the image
}
I'm receiving an image on a Metro app through network socket every 1 second, loading it in an array of bytes, then convert it to a BitmapImage and display it later. All of this work fine.
The image is changing constantly on the other side. For some reason, it throws an OutOfMemory exceptions from now and then(like 1 in 10) . I fixed it by clearing the array of bytes every time the image is received. Now it works like charm.
See below for my main issue:
public static BitmapImage imag;
public static byte[] save = new byte[1];
if(recieved)
{
await reader.LoadAsync(4);
var sz = reader.ReadUInt32(); //read size
await reader.LoadAsync(sz); //read content
save = new byte[sz];
reader.ReadBytes(save);
await ImgSrcFromBytes(save)
Array.Clear(save, 0, save.Length); //issue here !!
}
public async Task<ImageSource> ImgSrcFromBytes(byte[] a)
{
imag = new BitmapImage();
var stream = new Windows.Storage.Streams.InMemoryRandomAccessStream();
await stream.WriteAsync(a.AsBuffer());
stream.Seek(0);
imag.SetSource(stream);
return imag;
}
Now, i'm implementing a new function to save the image as a file if requested by the user with the code below, however, if i clear the array of bytes above, i get an unreadable image, but if i don't clear the array, i get a perfect image.
Note that no exceptions are thrown and both images have the same size.
FileSavePicker picker = new FileSavePicker();
picker.SuggestedStartLocation = PickerLocationId.PicturesLibrary;
picker.SuggestedFileName = "capture.png";
picker.FileTypeChoices.Add("Png File", new List<string>() { ".png" });
StorageFile file = await picker.PickSaveFileAsync();
if (file != null)
{
CachedFileManager.DeferUpdates(file);
await FileIO.WriteBytesAsync(file, save);
await CachedFileManager.CompleteUpdatesAsync(file);
await new Windows.UI.Popups.MessageDialog("Image Saved Successfully !").ShowAsync();
}
I hope i'm clear. It's a trade-off, if i clear the array, i will get no exceptions while receiving streams over sockets, but i won't be able to get a readable image when saving. and vice versa.
I managed to create the functionality to upload an image with the "gwtuploaded" to the app engine and store the image as an blob. My problem now is: The url that I get from imagesService.getServingUrl(suo) links to an image which is smaller than the image i uploaded. If i check the image in the blob viewer in the app engine console, it seems to have the correct size.
Why do I get a resized version of my image with the following code. Can I somehow retrieve the url to the full sized image?
My code looks like this:
public class MyUploadAction extends AppEngineUploadAction{
#Override
public String executeAction(HttpServletRequest request, List<FileItem> sessionFiles) throws UploadActionException {
String imageUrls = "";
// Image service is needed to get url from blob
ImagesService imagesService = ImagesServiceFactory.getImagesService();
// Get a file service -> write the blob
FileService fileService = FileServiceFactory.getFileService();
// Iterate over the files and upload each one
for(FileItem myFile : sessionFiles){
InputStream imgStream = null;
// construct our entity objects
Blob imageBlob = null;
// Create a new Blob file with mime-type "image/png"
AppEngineFile file = null;
FileWriteChannel writeChannel = null;
try {
// get input stream from file
imgStream = myFile.getInputStream();
imageBlob = new Blob(IOUtils.toByteArray(imgStream));
// create empty app engine file with mime type of uploaded file e.g.: image/png, image/jpeg
file = fileService.createNewBlobFile(myFile.getContentType());
// Open a channel to write to it
boolean lock = true;
writeChannel = fileService.openWriteChannel(file, lock);
// This time we write to the channel directly
writeChannel.write(ByteBuffer.wrap(imageBlob.getBytes()));
} catch (IOException e) {
e.printStackTrace();
}finally{
// Now finalize
try {
writeChannel.closeFinally();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// Get the url from the blob
ServingUrlOptions suo = ServingUrlOptions.Builder.withBlobKey(fileService.getBlobKey(file)).secureUrl(true);
imageUrls += imagesService.getServingUrl(suo);
imageUrls = imageUrls.replaceFirst("0.0.0.0", "127.0.0.1");
System.out.println(imageUrls);
}
return imageUrls ;
}
}
I tried and found that image service got a maximum image output of 1600x1600.
see here and search for 1600: https://developers.google.com/appengine/docs/java/images/
That applies even if you don't request for an resize.
To serve the image in original size, you shouldn't use the image service, just output directly from (e.g. blobstore)
I have used below code to fetch image from server. I have 60 different images placed on server. I have urls of all those images. By using while loop I am getting all these images but it's taking so much time to load image from server.
What can I do to get these images as fast as possible?
public Image getImagefromURL(String imageURL) {
DataInputStream is = null;
StringBuffer sb = new StringBuffer();
Image img = null;
try {
HttpConnection c = (HttpConnection) Connector.open(imageURL);
int len = (int) c.getLength();
if (len > 0) {
is = c.openDataInputStream();
byte[] data = new byte[len];
is.readFully(data);
img = Image.createImage(data, 0, len);
}
} catch (Exception e) {
e.printStackTrace();
}
return img;
}
And also one thing is happening that when I fetch first image, application is confirming me like "Application wants to connect to [URL of image location] using airtime. IS it ok to use airtime?" here I want to hide my path of image location. How can I do that?
The bigger the image, the longer it will take to load it. Make sure your PNG images are compressed with a tool, for example, PNGGauntlet.
You can also add a local cache on the application side using RMS.
And a last tip... You should not rely on HttpConnection.getLength, it might come as zero even when there is data to be read.
I'm trying to ascertain wither there is a limitation on the camera access in the j2me implementation on the HTC Touch2. The native camera is 3MP however it seams that the quality is notably reduced when accessed via j2me, in fact it seams that the only size and format the .getSnapshot() method is able to return is a 240x320 pixel jpeg. I'm trying to confirm that this is a limitation if the j2me implementation and not my coding. Hears and example of some of the things I have tried:
private void showCamera() {
try {
mPlayer = Manager.createPlayer("capture://video");
// mPlayer = Manager.createPlayer("capture://video&encoding=rgb565&width=640&height=480");
mPlayer.realize();
mVideoControl = (VideoControl)mPlayer.getControl("VideoControl");
canvas = new CameraCanvas(this, mVideoControl);
canvas.addCommand(mBackCommand);
canvas.addCommand(mCaptureCommand);
canvas.setCommandListener(this);
mDisplay.setCurrent(canvas);
mPlayer.start();
}
catch (Exception ex) {}
}
public void capture() {
try {
// Get the image.
byte[] raw = mVideoControl.getSnapshot("encoding=jpeg&quality=100&width=640&height=480");
// byte[] raw = mVideoControl.getSnapshot("encoding=png&quality=100&width=
// 640&height=480");
// byte[] raw = mVideoControl.getSnapshot(null);
Image image = Image.createImage(raw, 0, raw.length);
// Image thumb = createThumbnail(image);
// Place it in the main form.
if (mMainForm.size() > 0 && mMainForm.get(0) instanceof StringItem)
mMainForm.delete(0);
mMainForm.append(image);
If anyone could help it would be much appreciated.
I have reseved word from a number of sources that there is indeed a limitation on the camera access the JVM has witch is put in place by the operating system.