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Android MLKit face detection not detecting faces when using Bitmap

I have an XR app, where display shows the camera (rear) feed. As such, capturing the screen is pretty much the same as capturing the camera feed...
As such, I take screenshots (Bitmaps) and then try to detect faces within them using Googles MLKit.
I'm following the official guide to detect faces.
To do this, I first init my face detector:
FaceDetector detector;
public MyFaceDetector(){
FaceDetectorOptions realTimeOpts =
new FaceDetectorOptions.Builder()
.setContourMode(FaceDetectorOptions.CONTOUR_MODE_ALL)
.build();
detector = FaceDetection.getClient(realTimeOpts);
}
I then have a function which passes in a bitmap. I first convert the bitmap to a byte array. I do this because InputImage.fromBitmap is very slow, and MLKit actually tells me that I should use a byte array:
ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 85, byteArrayOutputStream);
byte[] byteArray = byteArrayOutputStream .toByteArray();
Next I make a mutable copy of the Bitmap (so that I can draw onto it), and set up a Canvas object, along with a color that will be used when drawing on to the Bitmap:
BitmapFactory.Options options = new BitmapFactory.Options();
options.inMutable = true;
Bitmap bmp = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length, options);
Canvas canvas = new Canvas(bmp);
Paint p = new Paint();
p.setColor(Color.RED);
After all is set up, I create an InputImage (used by the FaceDetector), using the byte array:
InputImage image = InputImage.fromByteArray(byteArray, bmp.getWidth(), bmp.getHeight(),0, InputImage.IMAGE_FORMAT_NV21);
Note the image format... There is a InputImage.IMAGE_FORMAT_BITMAP, but using this throws an IllegalArgumentException. Anyway, I next try to process the Bitmap, detect faces, fill each detected face with the color defined earlier, and then save the Bitmap to disk:
Task<List<Face>> result = detector.process(image).addOnSuccessListener(
new OnSuccessListener<List<Face>>() {
#Override
public void onSuccess(List<Face> faces) {
Log.e("FACE DETECTION APP", "NUMBER OF FACES: " + faces.size());
Thread processor = new Thread(new Runnable() {
#Override
public void run() {
for (Face face : faces) {
Rect destinationRect = face.getBoundingBox();
canvas.drawRect(destinationRect, p);
canvas.save();
Log.e("FACE DETECTION APP", "WE GOT SOME FACCES!!!");
}
File file = new File(someFilePath);
try {
FileOutputStream fOut = new FileOutputStream(file);
bmp.compress(Bitmap.CompressFormat.JPEG, 85, fOut);
fOut.flush();
fOut.close();
} catch (Exception e) {
e.printStackTrace();
}
}
});
processor.start();
}
})
.addOnFailureListener(
new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
// Task failed with an exception
// ...
}
});
}
While this code runs (i.e. no exceptions) and the bitmap is correctly written to disk, no faces are ever detected (faces.size() is always 0). I've tried rotating the image. I've tried changing the quality of the Bitmap. I've tried with and without the thread to process any detected faces. I've tried everything I can think of.
Anyone have any ideas?

ML Kit InputImage. fromByteArray only support yv12 and nv21 formats. You will need to convert the bitmap to one of these formats in order for ML kit pipeline to process. Also, if the original image you have is a bitmap, you can probably just use InputImage.fromBitmap to construct an InputImage. It shouldn't be slower than your current approach.

I was having the same issue use ImageInput.fromMediaImage(..., ...)
override fun analyze(image: ImageProxy) {
val mediaImage: Image = image.image.takeIf { it != null } ?: run {
image.close()
return
}
val inputImage = InputImage.fromMediaImage(mediaImage, image.imageInfo.rotationDegrees)
// TODO: Your ML Code
}
Check here for more details
https://developers.google.com/ml-kit/vision/image-labeling/android

save zoom image level to file

Let's say that I want to load an shp file, do my stuff on it and save the map as an image.
In order to save an image I am using:
public void saveImage(final MapContent map, final String file, final int imageWidth) {
GTRenderer renderer = new StreamingRenderer();
renderer.setMapContent(map);
Rectangle imageBounds = null;
ReferencedEnvelope mapBounds = null;
try {
mapBounds = map.getMaxBounds();
double heightToWidth = mapBounds.getSpan(1) / mapBounds.getSpan(0);
imageBounds = new Rectangle(0, 0, imageWidth, (int) Math.round(imageWidth * heightToWidth));
} catch (Exception e) {
// Failed to access map layers
throw new RuntimeException(e);
}
BufferedImage image = new BufferedImage(imageBounds.width, imageBounds.height, BufferedImage.TYPE_INT_RGB);
Graphics2D gr = image.createGraphics();
gr.setPaint(Color.WHITE);
gr.fill(imageBounds);
try {
renderer.paint(gr, imageBounds, mapBounds);
File fileToSave = new File(file);
ImageIO.write(image, "png", fileToSave);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
But, let's say I am doing something like this:
...
MapContent map = new MapContent();
map.setTitle("TEST");
map.addLayer(layer);
map.addLayer(shpLayer);
// zoom into the line
MapViewport viewport = new MapViewport(featureCollection.getBounds());
map.setViewport(viewport);
saveImage(map, "/tmp/img.png", 800);
1) The problem is that the zoom level isn't saved on the image file.Is there a way to save it?
2) When I am doing MapViewport(featureCollection.getBounds()); is there a way to extend a little bit the boundaries in order to have a better visual representation?
...

The reason that you aren't saving the map at the current zoom level is that in your saveImage method you have the line:
mapBounds = map.getMaxBounds();
which always uses the full extent of the map, you can change this to
mapBounds = map.getViewport().getBounds();
You can expand a bounding box by something like:
ReferencedEnvelope bounds = featureCollection.getBounds();
double delta = bounds.getWidth()/20.0; //5% on each side
bounds.expandBy(delta );
MapViewport viewport = new MapViewport(bounds);
map.setViewport(viewport );
A quicker (and easier) way to save a map from the GUI is to use a method like this which just saves exactly what is on the screen:
public void drawMapToImage(File outputFile, String outputType,
JMapPane mapPane) {
ImageOutputStream outputImageFile = null;
FileOutputStream fileOutputStream = null;
try {
fileOutputStream = new FileOutputStream(outputFile);
outputImageFile = ImageIO.createImageOutputStream(fileOutputStream);
RenderedImage bufferedImage = mapPane.getBaseImage();
ImageIO.write(bufferedImage, outputType, outputImageFile);
} catch (IOException ex) {
ex.printStackTrace();
} finally {
try {
if (outputImageFile != null) {
outputImageFile.flush();
outputImageFile.close();
fileOutputStream.flush();
fileOutputStream.close();
}
} catch (IOException e) {// don't care now
}
}
}

How to save an image in a set location?

I am trying to save a resized picture to the user's desktop but not sure how to do that.
Here's my code so far:
mi.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
String userhome = System.getProperty("user.home");
fileChooser = new JFileChooser(userhome + "\\Desktop");
fileChooser.setAutoscrolls(true);
switch (fileChooser.showOpenDialog(f)) {
case JFileChooser.APPROVE_OPTION:
BufferedImage img = null;
try {
img = ImageIO.read(fileChooser.getSelectedFile());
} catch (IOException e1) {
e1.printStackTrace();
}
Image dimg = img.getScaledInstance(f.getWidth(),
f.getHeight(), Image.SCALE_SMOOTH);
path = new ImageIcon(dimg);
configProps.setProperty("Path", fileChooser
.getSelectedFile().getPath());
imBg.setIcon(path);
break;
}
}
});
The code above resizes the imaged selected to fit the size of the JFrame then sets it to the JLabel.
This all works well but I also want to output the file to a set location lets say to the users desktop to make it easier. I'm currently looking at output stream but can't quite get my head around it.
Any help would be great.

Get the current Icon from the JLabel...
Icon icon = imgBg.getIcon();
Paint the icon to a BufferedImage...
BufferedImage img = new BufferedImage(icon.getIconWidth(), icon.getIconHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D g2d = img.createGraphics();
icon.paintIcon(null, g2d, 0, 0);
g2d.dispose();
Save the image to a file...
ImageIO.write(img, "png", new File("ResizedIcon.png"));
(and yes, you could use a JFileChooser to pick the file location/name)
You should also take a look at this for better examples of scaling an image, this way, you could scale the BufferedImage to another BufferedImage and save the hassle of having to re-paint the Icon
You might also like to take a look at Writing/Saving an Image

This is a example which is about saving images from Web to the local.
package cn.test.net;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
public class ImageRequest {
/**
* #param args
*/
public static void main(String[] args) throws Exception {
//a url from web
URL url = new URL("http://img.hexun.com/2011-06-21/130726386.jpg");
//open
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
//"GET"!
conn.setRequestMethod("GET");
//Timeout
conn.setConnectTimeout(5 * 1000);
//get data by InputStream
InputStream inStream = conn.getInputStream();
//to the binary , to save
byte[] data = readInputStream(inStream);
//a file to save the image
File imageFile = new File("BeautyGirl.jpg");
FileOutputStream outStream = new FileOutputStream(imageFile);
//write into it
outStream.write(data);
//close the Stream
outStream.close();
}
public static byte[] readInputStream(InputStream inStream) throws Exception{
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
//every time read length,if -1 ,end
int len = 0;
//a Stream read from buffer
while( (len=inStream.read(buffer)) != -1 ){
//mid parameter for starting position
outStream.write(buffer, 0, len);
}
inStream.close();
//return data
return outStream.toByteArray();
}
}
Hope this is helpful to you!

Disable text below barcode image in Code39Bean

This code creates BarCode Image along with Text below image .
I need to remove the text from image .
Code39Bean does not have any property to disable this .
public static ByteArrayOutputStream generateBarcodeImg(String inputId)
throws Exception {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Code39Bean bean = new Code39Bean();
final int dpi = 150;
/**
* Configure the bar-code generator and makes the narrow bar width
* exactly one pixel.
*/
bean.setModuleWidth(UnitConv.in2mm(1.0f / dpi));
bean.setWideFactor(3);
bean.doQuietZone(false);
try {
/** Set up the canvas provider for monochrome PNG output. */
BitmapCanvasProvider canvas = new BitmapCanvasProvider(baos,
BarCodeConstant.CONTENT_TYPE, dpi,
BufferedImage.TYPE_BYTE_BINARY, false, 0);
/** Generate the bar code. */
bean.generateBarcode(canvas, inputId);
/** Signal end of generation. */
canvas.finish();
} catch (IOException e) {
logger.error(
"Exception occured in BarcodeGeneration: generateBarcodeImg "
+ e.getLocalizedMessage(), e);
throw new MobileResourceException(
"Exception occured in BarcodeGeneration: generateBarcodeImg",
null);
}
return baos;
}
}

You can remove the text from Image through the "HumanReadablePlacement" property:
bean.setMsgPosition(HumanReadablePlacement.HRP_NONE);
This will suppress the human readable text of the barcode to NONE.

Screen capture using codes

I have transferred my code from a method (button press action) to a new class. Its function is to capture screen image (much like print screen) and saves it somewhere in the computer. (in this case, drive c) It displays the following error message:
java.io.FileNotFoundException: c:\z\1.jpg (The system cannot find the
path specified)
public class printScreen{
public static void main(String args[]) throws AWTException, IOException
{
Robot robot = new Robot();
Dimension a = Toolkit.getDefaultToolkit().getScreenSize();
Rectangle rect = new Rectangle(a);
BufferedImage img = robot.createScreenCapture(rect);
ImageIO.write(img, "jpg", new File("c:/z/1.jpg"));
ImageIO.write(img, "bmp", new File("c:/z/2.bmp"));
ImageIO.write(img, "png", new File("c:/z/3.png"));
}
}
Any thoughts? All help will greatly be appreciated! Thank you!

File f = new File("c:/z/1.jpg")
f.createNewFile();
ImageIO.write(img, "jpg", f);