图片处理

 1 public class BitmapUtil {
 2     
 3     private static BitmapFactory.Options opt;
 4     /**
 5      * 从SD Card中获取图片
 6      * 
 7      */
 8     public static Bitmap getBitmapFormSDCrad(String PicturePath) {
 9         Bitmap bitmap = null;
10         opt = new BitmapFactory.Options();
11         opt.inPreferredConfig = Bitmap.Config.RGB_565;
12         opt.inPurgeable = true;
13         opt.inInputShareable = true;
14         try {
15             InputStream iss = new FileInputStream(PicturePath);
16             opt.inJustDecodeBounds = true;
17             BitmapFactory.decodeStream(iss, null, opt);
18             if (opt.outWidth > 3000 || opt.outHeight > 3000) {
19                 opt.inSampleSize = 2;
20             }
21             opt.inJustDecodeBounds = false;
22             iss = new FileInputStream(PicturePath);
23             bitmap = BitmapFactory.decodeStream(iss, null, opt);
24             // 获取图片的原始拍摄角度，旋转修正
25             int rotatedDegree = readPictureDegree(PicturePath);
26             bitmap = rotateBitmap(bitmap, rotatedDegree);
27         } catch (FileNotFoundException e) {
28             Log.e("HeadColorView", e.toString());
29         }
30         return bitmap;
31     }
32 
33     /*
34      * 按照模板计算图片尺寸
35      */
36     private static int calculateInSampleSize(Options options, int reqWidth,
37             int reqHeight) {
38         final int height = options.outHeight;
39         final int width = options.outWidth;
40         int inSampleSize = 1;
41         //等比例缩放
42         if (height > reqHeight || width > reqWidth) {
43 
44             final int heightRatio = Math.round((float) height
45                     / (float) reqHeight);
46             final int widthRatio = Math.round((float) width / (float) reqWidth);
47             inSampleSize = heightRatio < widthRatio ? widthRatio : heightRatio;
48         }
49         return inSampleSize;
50     }
51 
52     /**
53      * 旋转图片，使图片保持正确的方向。
54      * @param bitmap 原始图片
55      * @param degrees 原始图片的角度
56      * @return Bitmap 旋转后的图片
57      */
58     public static Bitmap rotateBitmap(Bitmap bitmap, int degrees) {
59         if (degrees == 0 || null == bitmap) {
60             return bitmap;
61         }
62         Matrix matrix = new Matrix();
63         matrix.setRotate(degrees, bitmap.getWidth() / 2, bitmap.getHeight() / 2);
64         Bitmap bmp = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
65         if (null != bitmap) {
66             bitmap.recycle();
67         }
68         return bmp;
69     }
70 
71     /**
72      * 读取图片属性：旋转的角度
73      * @param path 图片绝对路径
74      * @return degree旋转的角度
75      */
76     private static int readPictureDegree(String filePath) {
77         int degree = 0;
78         try {
79             ExifInterface exifInterface = new ExifInterface(filePath);
80             int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION,ExifInterface.ORIENTATION_NORMAL);
81             switch (orientation) {
82             case ExifInterface.ORIENTATION_ROTATE_90:
83                 degree = 90;
84                 break;
85             case ExifInterface.ORIENTATION_ROTATE_180:
86                 degree = 180;
87                 break;
88             case ExifInterface.ORIENTATION_ROTATE_270:
89                 degree = 270;
90                 break;
91             }
92         } catch (IOException e) {
93             e.printStackTrace();
94             return degree;
95         }
96         return degree;
97     }
98 
99 }