Android scaling of images to screen density

Question

I have an application with an embedded drawable 48x48 pixel at 71,12 pixels/inch I load the same image via a stream to a webserver, then load that stream

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Answer 1

Get the current density of the screen and set the drawable to that density

DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
int density  =  metrics.densityDpi
myDrawable.setDensity(densityDpi);

Answer 2

Do something like this:

DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);

Bitmap bitmapOrg = new BitmapDrawable(getResources(), new  ByteArrayInputStream(imageThumbnail)).getBitmap();

int width = bitmapOrg.getWidth();
int height = bitmapOrg.getHeight();

float scaleWidth = metrics.scaledDensity;
float scaleHeight = metrics.scaledDensity;

// 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(bitmapOrg, 0, 0, width, height, matrix, true);

Or

Maybe try a differnet approach... try setting the height and width of images in the XML layout in dips, I am guessing you have the ImageView with wrap_content height and width at the moment, try setting the height and width to 48dip

Answer 3

you can trigger android bitmapfactory to scale bitmap automatically, codes for this:

BitmapFactory.Options options = new BitmapFactory.Options();
DisplayMetrics metrics = context.getApplicationContext().getResources().getDisplayMetrics();
options.inScreenDensity = metrics.densityDpi;
options.inTargetDensity =  metrics.densityDpi;
options.inDensity = DisplayMetrics.DENSITY_DEFAULT;

Bitmap bm = BitmapFactory.decodeStream(in, null, options);
in.close();
BitmapDrawable bitmapDrawable = new BitmapDrawable(context.getResources(), bm);