从相册中选择的图片如何调整大小

Question

从相册中选择的图片如何调整大小

3

我正在开发一个应用程序，可以从图库中选择一张图片并将其保存到Parse。但是，当我选择由相机拍摄的图像时，图像的大小太大了，在图像视图中加载图像需要几秒钟的时间。而且，当我保存图像并在应用程序中重新下载时，需要很长时间，因为它必须下载一个大图像。

我不知道如何缩小所选图像的大小。我尝试了几种方法，但没有任何作用。

这是我目前的代码：

public class Datos extends Activity implements OnItemSelectedListener {


private final int SELECT_PHOTO = 1;
private ImageButton imageView;


ParseFile file;
byte [] data;

/*
    public Bitmap getResizedBitmap(Bitmap bm, int newWidth, int newHeight) {
    int width = bm.getWidth();
    int height = bm.getHeight();
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;
    // CREATE A MATRIX FOR THE MANIPULATION
    Matrix matrix = new Matrix();
    // RESIZE THE BIT MAP
    matrix.postScale(scaleWidth, scaleHeight);

    // "RECREATE" THE NEW BITMAP
    Bitmap resizedBitmap = Bitmap.createBitmap(
            bm, 0, 0, width, height, matrix, false);
    bm.recycle();
    return resizedBitmap;
    }
*/


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.activity_datos);
    btnClick();

    imageView = (ImageButton) findViewById(R.id.imageButton);


    ImageButton pickImage = (ImageButton) findViewById(R.id.imageButton);
    pickImage.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View view) {
            Intent photoPickerIntent = new Intent(Intent.ACTION_PICK);
            photoPickerIntent.setType("image/*");
            //photoPickerIntent.putExtra("outputX", 150);
            //photoPickerIntent.putExtra("outputY", 100);
            //photoPickerIntent.putExtra("aspectX", 1);
            //photoPickerIntent.putExtra("aspectY", 1);
            //photoPickerIntent.putExtra("scale", true);
            startActivityForResult(photoPickerIntent, SELECT_PHOTO);
        }
    });

}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent imageReturnedIntent) {
    super.onActivityResult(requestCode, resultCode, imageReturnedIntent);


    switch (requestCode) {
        case SELECT_PHOTO:
            if (resultCode == RESULT_OK) {
                try {
                    Uri imageUri = imageReturnedIntent.getData();
                    InputStream imageStream = getContentResolver().openInputStream(imageUri);
                    Bitmap selectedImage = BitmapFactory.decodeStream(imageStream);
                    imageView.setImageBitmap(selectedImage);

                    ByteArrayOutputStream stream = new ByteArrayOutputStream();
                    selectedImage.compress(Bitmap.CompressFormat.PNG, 100, stream);

                    data = stream.toByteArray();

                    BitmapDrawable bitmapDrawable = new BitmapDrawable(getResources(), selectedImage);
                    imageView.setBackgroundDrawable(bitmapDrawable);

                    BitmapDrawable drawable = (BitmapDrawable) imageView.getDrawable();
                    Bitmap bmp = drawable.getBitmap();
                    Bitmap b = Bitmap.createScaledBitmap(bmp, 120, 120, false);


                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }


            }

    }
}



@Override
public void onItemSelected(AdapterView<?> parent, View v, int position,
                           long id) {
    // TODO Auto-generated method stub

    Spinner spinner = (Spinner) parent;
    if (spinner.getId() == R.id.telefono) {
        consola = parent.getItemAtPosition(position).toString();
    } else if (spinner.getId() == R.id.provincia) {
        provincia = parent.getItemAtPosition(position).toString();
    }

}

@Override
public void onNothingSelected(AdapterView<?> arg0) {
    // TODO Auto-generated method stub
}


public void btnClick() {

    Button buttonEnviar = (Button) findViewById(R.id.enviar);


    buttonEnviar.setOnClickListener(new OnClickListener() {


        @Override
        public void onClick(View arg0) {

            //Storing image in parse passed in  onclick method of a button with the below code:


            Intent intentDatos = new Intent(Datos.this, Inicio.class);
            startActivity(intentDatos);


            ParseObject testObject = new ParseObject("Musica");

            if (data != null) {

                file = new ParseFile("selected.png", data);
            }

            else {

                data = "".getBytes();
                file = new ParseFile("selected.png", data);
            }

            //file.saveInBackground();


            testObject.put("imagen", file);

            testObject.saveInBackground();




        }
    });


}

有人知道如何做吗？

谢谢你的帮助，

- Rec

可能是在Android中将位图大小减小到某些指定像素的重复问题。 - Rahul Tiwari

1个回答

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- Rahul Tiwari · Accepted Answer

这个答案可以帮助你。

如果您想让位图比例相同且减小位图大小，请传递您的最大大小位图。您可以使用此函数。

public Bitmap getResizedBitmap(Bitmap image, int maxSize) {
        int width = image.getWidth();
        int height = image.getHeight();

        float bitmapRatio = (float)width / (float) height;
        if (bitmapRatio > 1) {
            width = maxSize;
            height = (int) (width / bitmapRatio);
        } else {
            height = maxSize;
            width = (int) (height * bitmapRatio);
        }
        return Bitmap.createScaledBitmap(image, width, height, true);
}

把你在SELECT_PHOTO case中的onActivityResult更改为这样：

   case SELECT_PHOTO:
        if (resultCode == RESULT_OK) {
            try {
                Uri imageUri = imageReturnedIntent.getData();
                InputStream imageStream = getContentResolver().openInputStream(imageUri);
                Bitmap selectedImage = BitmapFactory.decodeStream(imageStream);

                selectedImage = getResizedBitmap(selectedImage, 400);// 400 is for example, replace with desired size

                imageView.setImageBitmap(selectedImage);


            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }