Android Byte Array to Bitmap rotate & resize 圖片旋轉、縮放

最近會用上這也是因為在拍照時需要做些處理，拍完原始檔太大要傳好久光想就很麻煩，最後決定將檔案縮小再傳是比較適當點，剛拍完的照片儲存方式為Byte Array，但作些圖像處理時大多需要轉換為Bitmap比較方便。

Byte Array to Bitmap
buteArrayName就是這byte array的名稱
Bitmap bitmap = BitmapFactory.decodeByteArray(byteArrayName, 0, byteArrayName.length);


Bitmap to Byte Array
其中"bitmap"就是Bitmap的變數名稱，90就是這照片的品質
ByteArrayOutputStream out = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 90, out);
byte[] array= out.toByteArray();


Rotate
Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
//set rotate
int w = bitmap.getWidth();
int h = bitmap.getHeight();

// Setting post rotate to 90
Matrix mtx = new Matrix();
mtx.postRotate(90);

// Rotating Bitmap
Bitmap rotatedBMP = Bitmap.createBitmap(bitmap, 0, 0, w, h, mtx, true);
//BitmapDrawable bmd = new BitmapDrawable(rotatedBMP); //如果要在畫面中顯示才需要


resize

Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);

//set rotate
int w = bitmap.getWidth();
int h = bitmap.getHeight();

//set final size
int destWidth = 480;
int destHeigth = 800;

//set scale size
float scaleWidth = ((float) destWidth) / w;
float scaleHeight = ((float) destHeigth) / h;

//set resize
Matrix mtx = new Matrix();
mtx.postScale(scaleWidth, scaleHeight);

// Rotating Bitmap
Bitmap rotatedBMP = Bitmap.createBitmap(bitmap, 0, 0, w, h, mtx, true);
//BitmapDrawable bmd = new BitmapDrawable(rotatedBMP); //如果要在畫面中顯示才需要


相關連結
Android Developer
Android Developer - Bitmap
Android Developer - BitmapDrawable
Android Developer - ByteArrayOutputStream
Android Developer - BitmapFactory