android – Previewing the camera in framelayout mode with distorted image

Again, need help!

I develop an app that uses the smartphone's camera only for display, ie it will not save photos or videos, but only a preview.

Already managed to open the smartphone camera in Activity and all. The problem was that I noticed the camera view of my application compared to other applications and the default application of my smartphone and that I found that my application was distorting the picture. image displayed on my camera.

Below are the pictures to illustrate what is happening.

Note: Both images were taken at the same distance and in the same position.

Image 1 – Standard camera and normal smartphone mode (ORIENTATION_LANDSCAPE)

enter the description of the image here

Image 2 – Camera of my application and normal mode (ORIENTATION_LANDSCAPE)

enter the description of the image here

Note that photo 1, is sharper and "thinner", ie the size of the original image without zoom is included. Already photo 2, is flattened "chubby", that is to say deformed.

Below the class code, layout xml and manifest file of the application:

XML




    

    

JAVA ACTIVITY CLASS

public class MainActivity extends AppCompatActivity {

Camera camera;
FrameLayout frameLayout;
CameraPreview cameraPreview;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    frameLayout = findViewById(R.id.frameLayoutCameraPreview);
    camera = Camera.open();
    cameraPreview = new CameraPreview(this, camera);
    frameLayout.addView(cameraPreview);

}

@Override
public void onWindowFocusChanged(boolean hasFocus) {
    super.onWindowFocusChanged(hasFocus);
    View decorView = getWindow().getDecorView();
    if (hasFocus){
        decorView.setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
                | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN
                | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION
                | View.SYSTEM_UI_FLAG_FULLSCREEN
                | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION);
    }
}

@Override
protected void onPause() {
    super.onPause();
    if (camera != null){
        camera.stopPreview();
        camera.release();
        camera = null;
    }
}

}

CAMERA DISPLAY JAVA CLASS

public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback{

Camera camera;
SurfaceHolder holder;

public CameraPreview(Context context, Camera camera) {
    super(context);

    this.camera = camera;
    this.holder = getHolder();
    this.holder.addCallback(this);

}

@Override
public void surfaceCreated(SurfaceHolder holder) {
    Camera.Parameters parameters = camera.getParameters();
    List sizes = parameters.getSupportedPictureSizes();
    Camera.Size mSize = null;

    for (Camera.Size size: sizes){
        mSize = size;
    }

    if (this.getResources().getConfiguration().orientation != Configuration.ORIENTATION_LANDSCAPE){
        parameters.set("orientation", "portrait");
        camera.setDisplayOrientation(90);
        parameters.setRotation(90);
    }else {
        parameters.set("orientation", "portrait");
        camera.setDisplayOrientation(0);
        parameters.setRotation(0);
    }

    parameters.setPictureSize(mSize.width, mSize.height);
    camera.setParameters(parameters);

    try {
        camera.setPreviewDisplay(holder);
        camera.startPreview();
    } catch (IOException e){
        e.printStackTrace();
    }
}

@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {

}

@Override
public void surfaceDestroyed(SurfaceHolder holder) {
    camera.stopPreview();
    camera.release();
}

}

ANDROID MANIFEST




    

    
        
            
                

                
            
        
    

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It does not seem like a good investment.

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The answer to this is therefore that the angular resolution limit of an optical system with a front element diameter d, operating at a wavelength of λ is given by

Δθ = 1.22 λ / d

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We also mention this perhaps Canon's mythical goal 5200mm. It is difficult to find specifications for this, but I found a place that claims overall dimensions of 500 mm by 600 mm by 1890 mm: if they are correct, the front element has no more than 500 mm in diameter, so we get r = 8 km for this purpose. So, in particular, it will not let you see faces tens of kilometers away, which the media hype involves in a way.

You can of course use this formula for any purpose: for example, it explains to you why you can not see the Apollo landing sites on the moon from Earth with a plausible telescope !