在android中调整到413*531像素后，图像看起来模糊

Question

在我的应用程序中，我捕获图像，然后在第二个活动中应用裁剪，然后调整捕获图像的大小并将其发送到服务器。保存的图像看起来模糊。如何在调整大小后以良好的质量保存图像。下面是我的代码:

 PassImageBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Bitmap photo = getIntent().getExtras().getParcelable("image");
                resultIv.setImageBitmap(photo);
                // CALL THIS METHOD TO GET THE URI FROM THE BITMAP
                Uri tempUri = getImageUri(getApplicationContext(), photo);
                // CALL THIS METHOD TO GET THE ACTUAL PATH
                File finalFile = new File(getRealPathFromURI(tempUri));
                int x = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, 413, getResources().getDisplayMetrics());
                int y = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, 531, getResources().getDisplayMetrics());
                cropView.of(Uri.fromFile(finalFile)).withAspect(x, y).initialize(Image.this);
            }
        });
           @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                //Converting Bitmap to String
                String image = getStringImage(croppedBitmap);         
                Map<String, String> params = new Hashtable<String, String>();
                //Adding parameters
                params.put(KEY_IMAGE, image);        
                return params;
            }
    //resize image
    public String getStringImage(Bitmap bmp) {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        int width = 413;
        int height = 531;
        Bitmap bm = Bitmap.createScaledBitmap(bmp, width, height, false);
        bm.compress(Bitmap.CompressFormat.PNG, 100, baos);
        byte[] imageBytes = baos.toByteArray();
        String encodedImage = Base64.encodeToString(imageBytes, Base64.DEFAULT);
        return encodedImage;
    }

Answer 1

使用以下方法压缩图像:

public String bitmapToBase64(Bitmap bitmap) {
        String imageBase64String;
        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, byteArrayOutputStream);
        byte[] byteArray = byteArrayOutputStream.toByteArray();
        imageBase64String = Base64.encodeToString(byteArray, Base64.DEFAULT);
        return imageBase64String;
    } 

反编译:

 private Bitmap decodeFile(File f) {
        try {
            // decode image size
            BitmapFactory.Options o = new BitmapFactory.Options();
            o.inJustDecodeBounds = true;
            BitmapFactory.decodeStream(new FileInputStream(f), null, o);
            // Find the correct scale value. It should be the power of 2.
            final int REQUIRED_SIZE = 512;
            int width_tmp = o.outWidth, height_tmp = o.outHeight;
            int scale = 1;
            while (true) {
                if (width_tmp / 2 < REQUIRED_SIZE || height_tmp / 2 < REQUIRED_SIZE)
                    break;
                width_tmp /= 2;
                height_tmp /= 2;
                scale *= 2;
            }
            // decode with inSampleSize
            BitmapFactory.Options o2 = new BitmapFactory.Options();
            o2.inSampleSize = scale;
            return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
        } catch (FileNotFoundException e) {
        }
        return null;
    }