I am experimenting with the android FaceDetector.
I need to use a bitmap file (faces.bmp is from a group photo) since I have not found a way to use the android camera in the android emulator.
But BitmapFactory.decodeFile returns null and the documentation only says it returns null if the bitmap could not be decoded. It is just a 24 bit .bmp file. I am using Eclipse on Windows 7. Did I specify pathName incorrectly? Do I need to use something other than a 24 bit .bmp file?
public class MyFaces extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
final int width = 600;
final int height = 600;
final int maxFaces = 8;
FaceDetector faceDetector = new FaceDetector(width, height, maxFaces);
String pathName = "../res/drawable-hdpi/faces.bmp";
try {
Bitmap bitmap = BitmapFactory.decodeFile(pathName);
Face faces[] = new Face[maxFaces];
int nFaces = faceDetector.findFaces(bitmap, faces);
Log.d(this.getClass().toString(), "Faces: " + nFaces);
} catch (Exception e) {
Log.e(this.getClass().toString(), e.getMessage(), e);
}
}
}
If you are just testing then in place of Bitmap bitmap = BitmapFactory.decodeFile(pathName); you could use:
Bitmap bitmap = BitmapFactory.decodeResource(R.drawable.faces);
Related
I'm having a problem with android's camera2 API.
My end goal here is to have a byte array which I can edit using opencv, whilst displaying the preview to the user (e.g. an OCR with a preview).
I've create a capture request and added an ImageReader as a target. Then on the OnImageAvailableListener, i'm getting the image, transforming it to a bitmap and then display it on an ImageView (and rotating it).
My problem is that after a few seconds, the preview stalls (after gradually slowing down) and in the log om getting the following error: E/BufferItemConsumer: [ImageReader-1225x1057f100m2-18869-0] Failed to release buffer: Unknown error -1 (1)
As you can see in my code, I have already tried closing the img after getting my byte[] from it.
I've also tried clearing the buffer.
I've tried closing the ImageReader but that of course stopped me from getting any further images (throws an exception).
Can anyone please help me understand what im doing wrong? I've been scouring google to no avail.
This is my OnImageAvailableListener, do let me know if you need more of my code to assist:
private final ImageReader.OnImageAvailableListener mOnImageAvailableListener
= new ImageReader.OnImageAvailableListener() {
#Override
public void onImageAvailable(ImageReader reader) {
Image img = reader.acquireLatestImage();
final ImageView iv = findViewById(R.id.camPrev);
try{
if (img==null) throw new NullPointerException("null img");
ByteBuffer buffer = img.getPlanes()[0].getBuffer();
byte[] data = new byte[buffer.remaining()];
buffer.get(data);
final Bitmap b = BitmapFactory.decodeByteArray(data, 0, data.length);
runOnUiThread(new Runnable() {
#Override
public void run() {
iv.setImageBitmap(b);
iv.setRotation(90);
}
});
} catch (NullPointerException ex){
showToast("img is null");
}finally {
if(img!=null)
img.close();
}
}
};
Edit - adding cameraStateCallback
private CameraDevice.StateCallback mCameraDeviceStateCallback = new CameraDevice.StateCallback() {
#Override
public void onOpened(CameraDevice cameraDevice) {
mCameraDevice = cameraDevice;
showToast("Connected to camera!");
createCameraPreviewSession();
}
#Override
public void onDisconnected(CameraDevice cameraDevice) {
closeCamera();
}
#Override
public void onError(CameraDevice cameraDevice, int i) {
closeCamera();
}
};
private void closeCamera() {
if (mCameraDevice != null) {
mCameraDevice.close();
mCameraDevice = null;
}
}
You seem to have used setRepeatingRequest() for Jpeg format. This may not be fully supported on your device, also depends on the image resolution that you choose. Normally, we use createCaptureRequest(CameraDevice.TEMPLATE_PREVIEW) in these cases, and get YUV or raw format from ImageReader.
I would try to choose low resolution for Jpeg: maybe this will be enough to keep the ImageReader running.
I'm trying to use an Activity which displays a random object from my array. This object is passed in from an intent.
I am trying to use an image for each of these objects and then display the correct image for the correct object.
So far I've been using the drawable folder to hold my images and then loading them in through the XML however this stops me using multiple images for the same ImageView.
I tried using imageview.setImageResource(R.drawable.imagename); but that doesn't seem to like loading in for some reason.
Do I need to make a new activity for each of the objects in this case?
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_random_race);
TextView name = (TextView)findViewById(R.id.raceName);
Intent secondIntent = getIntent();
Race message = (Race)secondIntent.getSerializableExtra("RACE");
ImageView image = (ImageView) findViewById(R.id.raceImage);
image.setImageResource(R.drawable.hacan);
image.setImageBitmap(imageToBitmapImage(message, image));
name.setText(message.getName());
}
Bytes to Bitmap method
public Bitmap imageToBitmapImage (Race message, ImageView image){
Bitmap bmp;
try {
FileInputStream in = new FileInputStream(message.getImageName());
BufferedInputStream buffer = new BufferedInputStream(in);
ByteArrayOutputStream baos = new ByteArrayOutputStream();
int input = buffer.read();
while (input != -1){
baos.write(input);
input = buffer.read();
}
byte[] bytes = baos.toByteArray();
bmp = BitmapFactory.decodeByteArray(bytes, 0, bytes.length);
return bmp;
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}
Class of each object I'm talking about.
public class Race implements Serializable {
private String name;
private String imageName; //name of file within drawable
As #XavierFalempin commented, you can't access ressources through a file stream. Using setImageResource() should work. Following this answer your onCreate() method should look something like this:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_random_race);
TextView name = (TextView)findViewById(R.id.raceName);
Intent secondIntent = getIntent();
Race message = (Race)secondIntent.getSerializableExtra("RACE");
ImageView image = (ImageView) findViewById(R.id.raceImage);
image.setImageResource(getResources().getIdentifier(message.getImageName(),
"drawable",
getPackageName()));
name.setText(message.getName());
}
I would like to enter multiple text fields for example
name
email
password
address
And then I would like to generate a QR code from this input. How can I do that in android studio?
Setting up the library and manifest
Open App level gradle file and import the library.
implementation 'androidmads.library.qrgenearator:QRGenearator:1.0.3'
The, click “Sync Now”.
Then, open your Manifest file and add the following permissions. It is used to save QR Code to file storage.
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
We need to handle runtime permissions from Android Version 6.0.
Generating QR Code
QRGEncoder qrgEncoder = new QRGEncoder(inputValue, null, QRGContents.Type.TEXT, smallerDimension);
Here, inputValue is an input to be converted to QR Code.
Input Type also can be specified while initializing the library.
We can specify the dimensions also.
Then, add the following lines to create QR Code and encode that into Bitmap Format.
try {
// Getting QR-Code as Bitmap
bitmap = qrgEncoder.encodeAsBitmap();
// Setting Bitmap to ImageView
qrImage.setImageBitmap(bitmap);
} catch (WriterException e) {
Log.v(TAG, e.toString());
}
qrImage is an ImageView used to preview the generated QR code bitmap.
Saving QR Code
QR Generator has an option to save the generated QR Code Bitmap to storage using the following lines.
// Save with location, value, bitmap returned and type of Image(JPG/PNG).
QRGSaver.save(savePath, edtValue.getText().toString().trim(), bitmap, QRGContents.ImageType.IMAGE_JPEG);
We can save QR Code in PNG & JPG format also. We have to handle runtime permissions from Android version 6.0.
Your particular case:
Combine the information you want to encode in the QR code, and add it as the inputValue for the QRGEncoder. Here is an example code for clarity:
public class MainActivity extends AppCompatActivity {
String TAG = "GenerateQRCode";
EditText edtValue;
ImageView qrImage;
Button start, save;
String inputValue;
String savePath = Environment.getExternalStorageDirectory().getPath() + "/QRCode/";
Bitmap bitmap;
QRGEncoder qrgEncoder;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
qrImage = (ImageView) findViewById(R.id.QR_Image);
edtValue = (EditText) findViewById(R.id.edt_value);
start = (Button) findViewById(R.id.start);
save = (Button) findViewById(R.id.save);
start.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
inputValue = edtValue.getText().toString().trim();
if (inputValue.length() > 0) {
WindowManager manager = (WindowManager) getSystemService(WINDOW_SERVICE);
Display display = manager.getDefaultDisplay();
Point point = new Point();
display.getSize(point);
int width = point.x;
int height = point.y;
int smallerDimension = width < height ? width : height;
smallerDimension = smallerDimension * 3 / 4;
qrgEncoder = new QRGEncoder(
inputValue, null,
QRGContents.Type.TEXT,
smallerDimension);
try {
bitmap = qrgEncoder.encodeAsBitmap();
qrImage.setImageBitmap(bitmap);
} catch (WriterException e) {
Log.v(TAG, e.toString());
}
} else {
edtValue.setError("Required");
}
}
});
save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
boolean save;
String result;
try {
save = QRGSaver.save(savePath, edtValue.getText().toString().trim(), bitmap, QRGContents.ImageType.IMAGE_JPEG);
result = save ? "Image Saved" : "Image Not Saved";
Toast.makeText(getApplicationContext(), result, Toast.LENGTH_LONG).show();
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
}
Article: https://www.c-sharpcorner.com/article/how-to-generate-qr-code-in-android/
Concatenate all the information in a string and do a hash on said string. Next use a library such as (https://github.com/zxing/zxing) to generate the QR code.
Use this for generating qr code online. Then use picasso to load the image. ( Use your data in the url parameter )
https://chart.googleapis.com/chart?chs=500x500&cht=qr&chl=data
I found it as the best way.
I'm a beginner on Android Studio, and java, i want to create a random background of view images, i try to use this How To Display Random images on image view , but not working, this code doesn't generate any image
Please, can someone help me to resolve this code or to create another code to random background.
I use this code to generate images
final Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.rnd_images);
final ImageView img = (ImageView) findViewById(R.id.imgRandom);
// I have 3 images named img_0 to img_2, so...
final String str = "img_" + rnd.nextInt(2);
img.setImageDrawable
(
getResources().getDrawable(getResourceID(str, "drawable",
getApplicationContext()))
);
}
protected final static int getResourceID
(final String resName, final String resType, final Context ctx)
{
final int ResourceID =
ctx.getResources().getIdentifier(resName, resType,
ctx.getApplicationInfo().packageName);
if (ResourceID == 0)
{
throw new IllegalArgumentException
(
"No resource string found with name " + resName
);
}
else
{
return ResourceID;
}
}
}
Just two things, is this a good simple way to grab images? also when i do try it on the android AVD nothing gets displayed on screen as well as in log_cat, no errors or crashes. Here is my code:
public class MainActivity extends Activity {
Bitmap bitmap = null;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
try{
bitmap = getBitmap("https://twimg0-a.akamaihd.net/profile_images/2275552571/image_normal.jpg");
ImageView img = (ImageView) findViewById(R.id.img);
img.setImageBitmap(bitmap);
}catch(Exception e){
}
}
public Bitmap getBitmap(String bitmapUrl) {
try {
URL url = new URL(bitmapUrl);
return BitmapFactory.decodeStream(url.openConnection().getInputStream());
}catch(Exception ex) {return null;}
}
}
try : http://code.google.com/p/android-imagedownloader/ .
You can download remote images synchronously, Asynchronously, etc. it works really good
ImageDownloader imageDownloader = new ImageDownloader();
imageDownloader.setMode(ImageDownloader.Mode.CORRECT);
ImageView imageView = (ImageView) rowView.findViewById(R.id.picture);
imageView.setLayoutParams(new GridView.LayoutParams(140, 140));
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
imageView.setPadding(4, 4, 4, 4);
List<ImageSize> images = this.pictures.get(position).getImages();
imageDownloader.download(images.get(images.size()-3).getSource(), imageView);
It doesn't work because your picture's url starts with HTTPS. Try to use HttpGet. Something like that.