android 图片缩放与旋转

一．装载图片

BitmapFactory.decodeFile(pathName);

二．缩放图片

Matrix matrix = new Matrix();??
matrix.reset();
float scaleWidth = ((float) 320) / bitmap.getWidth();
float scaleHeight = ((float) 240) / bitmap.getHeight();
matrix.postScale(scaleWidth, scaleHeight);
bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);

三．旋转图片

Matrix matrix = new Matrix();?
matrix.reset();
matrix.postRotate(180);
bitmap = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix,true);

四．保存图片

File file = new File(path);
FileOutputStream outStream = null;
try
{
outStream = new FileOutputStream(file);
bitmap.compress(CompressFormat.JPEG, 100, outStream);
???outStream.close();
}
catch (Exception e)
{
e.printStackTrace();
}

?