/**
* 质量压缩方法
*
* @param imagePath 原图片路劲
* @param size 压缩图片到多少KB以内(单位KB)
* @return 返回压缩后图片的绝对路径
*/
public static File compressImageToSD(String imagePath, long size) {
Log.i("======开始压缩图片======");
ByteArrayOutputStream baos = new ByteArrayOutputStream();
Bitmap image = BitmapFactory.decodeFile(imagePath);
image.compress(Bitmap.CompressFormat.JPEG, 100, baos);// 质量压缩方法,这里100表示不压缩,把压缩后的数据存放到字节流中
int options = 90;
long fileSize = baos.toByteArray().length / 1024;
if (fileSize / size > 5) {
options = 20;
} else if (fileSize / size > 4) {
options = 25;
} else if (fileSize / size > 3) {
options = 30;
} else if (fileSize / size > 2) {
options = 50;
}
while (fileSize > size && options > 0) { // 循环判断如果压缩后图片是否大于1024kb,大于继续压缩
baos.reset(); // 重置baos即清空baos
image.compress(Bitmap.CompressFormat.JPEG, options, baos);// 这里压缩options%,把压缩后的数据存放到字节流中
Log.i("=压缩到原来=" + options + "%");
options -= 10;// 每次都减少10
fileSize = baos.toByteArray().length / 1024;
}
Log.i("===图片压缩结束===");
InputStream isBm = new ByteArrayInputStream(baos.toByteArray());// 把压缩后的字节存放到ByteArrayInputStream中
Context application = BaseApplication.getContext();
File appDir = new File(application.getExternalFilesDir(null), "temp");
if (!appDir.exists() && appDir.mkdir()) {
Log.d("", appDir.getName() + "目录创建成功");
}
String fileName = System.currentTimeMillis() + ".jpg";
File file = new File(appDir, fileName);
try {
Log.i("==压缩后的图片保存到SD==");
FileOutputStream fos = new FileOutputStream(file);
int temp = isBm.available();
int bytesRead;
byte[] buffer = new byte[isBm.available()];
while ((bytesRead = isBm.read(buffer, 0, temp)) != -1) {
LogUtil.i("==" + bytesRead);
fos.write(buffer, 0, bytesRead);
}
fos.flush();
fos.close();
isBm.close();
Log.i("==保存到SD成功==");
} catch (IOException e) {
e.printStackTrace();
}
return file;
}
//计算图片的缩放值
public static int calculateInSampleSize(BitmapFactory.Options options) {
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;
float reqWidth = (((float) height) / 10) * 9;
float reqHeight = (((float) width) / 10) * 9;
if (reqWidth > 480 && reqHeight > 800) {
inSampleSize = 2;
}
return inSampleSize;
}