android中常用的图片处理方法，涉及uri位图等多种图片转换

/**
* Created by sunshaobei on 2017/3/15.
*/

public class OwnUtil {
public static String compressImage(String filePath, String targetPath, int quality) {
Bitmap bm = getSmallBitmap(filePath);//获取一定尺寸的图片
File outputFile = new File(targetPath);
try {
if (!outputFile.exists()) {
outputFile.getParentFile().mkdirs();
//outputFile.createNewFile();
} else {
outputFile.delete();
}
FileOutputStream out = new FileOutputStream(outputFile);
bm.compress(Bitmap.CompressFormat.JPEG, quality, out);
} catch (Exception e) {
}
return outputFile.getPath();
}

/**
* 根据路径获得图片信息并按比例压缩，返回bitmap
*/
public static Bitmap getSmallBitmap(String filePath) {
final BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;//只解析图片边沿，获取宽高
BitmapFactory.decodeFile(filePath, options);
// 计算缩放比
options.inSampleSize = calculateInSampleSize(options, 480, 800);
// 完整解析图片返回bitmap
options.inJustDecodeBounds = false;
return BitmapFactory.decodeFile(filePath, options);
}

public static int calculateInSampleSize(BitmapFactory.Options options,
int reqWidth, int reqHeight) {
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
if (height > reqHeight || width > reqWidth) {
final int heightRatio = Math.round((float) height / (float) reqHeight);
final int widthRatio = Math.round((float) width / (float) reqWidth);
inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
}
return inSampleSize;
}

/**
* 从uri中获取bitmap
*
* @param uri
* @return
*/
public static String getRealPathFromURI(Activity activity, Uri uri) {
String[] proj = {
MediaStore.Video.Media.DISPLAY_NAME,
MediaStore.Video.Media.SIZE,
MediaStore.Images.Media.DATA,//绝对路径
MediaStore.Video.Media.MIME_TYPE
};
Cursor cursor = activity.getContentResolver().query(uri, proj, null, null, null);
int audioColumnIndex = cursor.getColumnIndexOrThrow(MediaStore.Audio.Media.DATA);
cursor.moveToFirst();
String path = cursor.getString(audioColumnIndex);
return path;
}

/**
* 将本地资源转换成bitmap
*
* @param filePath
* @return
*/
public static Bitmap getVideoThumbnail(String filePath) {
Bitmap bitmap = null;
MediaMetadataRetriever retriever = new MediaMetadataRetriever();
try {
retriever.setDataSource(filePath);
bitmap = retriever.getFrameAtTime();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (RuntimeException e) {
e.printStackTrace();
} finally {
try {
retriever.release();
} catch (RuntimeException e) {
e.printStackTrace();
}
}
return bitmap;
}

public static String saveBitmapFile(Bitmap bitmap) {
String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/Papaqun/image.jpg";
File file = new File(path);//将要保存图片的路径
BufferedOutputStream bos = null;
try {
bos = new BufferedOutputStream(new FileOutputStream(file));
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, bos);
bos.flush();
bos.close();
} catch (IOException e) {
e.printStackTrace();
} finally {
if (bos != null) {
try {
bos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
return path;
}

@SuppressLint("NewApi")
public static String getPathByUri4kitkat(final Context context, final Uri uri) {
final boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
// DocumentProvider
if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
if (isExternalStorageDocument(uri)) {// ExternalStorageProvider
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/" + split[1];
}
} else if (isDownloadsDocument(uri)) {// DownloadsProvider
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(Uri.parse("content://downloads/public_downloads"),
Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
} else if (isMediaDocument(uri)) {// MediaProvider
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[]{split[1]};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
} else if ("content".equalsIgnoreCase(uri.getScheme())) {// MediaStore
// (and
// general)
return getDataColumn(context, uri, null, null);
} else if ("file".equalsIgnoreCase(uri.getScheme())) {// File
return uri.getPath();
}
return null;
}

public static String getDataColumn(Context context, Uri uri, String selection, String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = {column};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
if (cursor != null && cursor.moveToFirst()) {
final int column_index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(column_index);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}

/**
* @param uri The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}

/**
* @param uri The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}

/**
* @param uri The Uri to check.
* @return Whether the
9f75
Uri authority is MediaProvider.
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}
}