bitmap图像工具

public static Bitmap getToBitmap(String path, int w, int h) {
BitmapFactory.Options opts = new BitmapFactory.Options();
// 设置为ture只获取图片大小
opts.inJustDecodeBounds = true;
opts.inPreferredConfig = Bitmap.Config.ARGB_8888;
// 返回为空
BitmapFactory.decodeFile(path, opts);
int width = opts.outWidth;
int height = opts.outHeight;
float scaleWidth = 0.f, scaleHeight = 0.f;
if (width > w || height > h) {
// 缩放
scaleWidth = ((float) width) / w;
scaleHeight = ((float) height) / h;
}
opts.inJustDecodeBounds = false;
float scale = Math.max(scaleWidth, scaleHeight);
opts.inSampleSize = (int) scale;
WeakReference<Bitmap> weak = new WeakReference<Bitmap>(
BitmapFactory.decodeFile(path, opts));
return Bitmap.createScaledBitmap(weak.get(), w, h, true);
}

public static byte[] bitmap2Bytes(Bitmap bitmap) {
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.PNG, 100, baos);
return baos.toByteArray();
}

public static Bitmap Bytes2Bitmap(byte[] b) {
if (b.length != 0) {
return BitmapFactory.decodeByteArray(b, 0, b.length);
} else {
return null;
}
}

public static void writeImageToDisk(byte[] img, String fileName) {
try {
String path=Environment.getExternalStorageDirectory().toString() + File.separator + "image/";
File file = new File(path);
if(!file.exists()){
file.mkdirs();
}
File photoFile=new File(path,fileName+".png");
FileOutputStream fops = new FileOutputStream(photoFile);
fops.write(img);
fops.flush();
fops.close();
} catch (Exception e) {
e.printStackTrace();
}
}

public static List<String> getImagePath() {
List<String> imagePathList = new ArrayList<String>();
String filePath = Environment.getExternalStorageDirectory().toString() + File.separator + "image";
File fileAll = new File(filePath);
File[] files = fileAll.listFiles();
for (int i = 0; i < files.length; i++) {
File file = files[i];
if (checkIsImageFile(file.getPath())) {
imagePathList.add(file.getPath());
}
}
return imagePathList;
}
//检查扩展名，得到图片格式的文件
private static boolean checkIsImageFile(String fName) {
boolean isImageFile = false;
String FileEnd = fName.substring(fName.lastIndexOf(".") + 1,fName.length()).toLowerCase();
if (FileEnd.equals("jpg") || FileEnd.equals("png") || FileEnd.equals("gif")
|| FileEnd.equals("jpeg")|| FileEnd.equals("bmp") ) {
isImageFile = true;
} else {
isImageFile = false;
}
return isImageFile;
}

public static Bitmap revitionImageSize(String path) throws IOException {
BufferedInputStream in = new BufferedInputStream(new FileInputStream(
new File(path)));
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeStream(in, null, options);
in.close();
int i = 0;
Bitmap bitmap = null;
while (true) {
if ((options.outWidth >> i <= 1000)
&& (options.outHeight >> i <= 1000)) {
in = new BufferedInputStream(
new FileInputStream(new File(path)));
options.inSampleSize = (int) Math.pow(2.0D, i);
options.inJustDecodeBounds = false;
bitmap = BitmapFactory.decodeStream(in, null, options);
break;
}
i += 1;
}
return bitmap;
}

public static Bitmap zoomBitmap(Bitmap bitmap, int width, int height) {
if (bitmap == null)
return bitmap;
int w = bitmap.getWidth();
int h = bitmap.getHeight();
Matrix matrix = new Matrix();
float scaleWidth = ((float) width / w);
float scaleHeight = ((float) height / h);
if (scaleWidth < scaleHeight) {
matrix.postScale(scaleWidth, scaleWidth);
} else {
matrix.postScale(scaleHeight, scaleHeight);
}
Bitmap newbmp = Bitmap.createBitmap(bitmap, 0, 0, w, h, matrix, true);
return newbmp;
}