09-16 压缩图片

压缩图片

public class ZipImage {
public static void zipImage(String savePath) {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(savePath, options);
options.inSampleSize = computeInitialSampleSize(options, 480, 480 * 960);
options.inJustDecodeBounds = false;
Bitmap bitmap = BitmapFactory.decodeFile(savePath, options);
try {
FileOutputStream fos = new FileOutputStream(savePath);
bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fos);
fos.flush();
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
bitmap.recycle();
bitmap = null;
System.gc();
}
public static int computeSampleSize(BitmapFactory.Options options,
int minSideLength, int maxNumOfPixels) {
int initialSize = computeInitialSampleSize(options, minSideLength,
maxNumOfPixels);
int roundedSize;
if (initialSize <= 8) {
roundedSize = 1;
while (roundedSize < initialSize) {
roundedSize <<= 1;
}
} else {
roundedSize = (initialSize + 7) / 8 * 8;
}
return roundedSize;
}

private static int computeInitialSampleSize(BitmapFactory.Options options,                                     int minSideLength, int maxNumOfPixels) {    double w = options.outWidth;    double h = options.outHeight;    int lowerBound = (maxNumOfPixels == -1) ? 1 : (int) Math.ceil(Math            .sqrt(w * h / maxNumOfPixels));    int upperBound = (minSideLength == -1) ? 128 : (int) Math.min(            Math.floor(w / minSideLength), Math.floor(h / minSideLength));    if (upperBound < lowerBound) {        // return the larger one when there is no overlapping zone.        return lowerBound;    }    if ((maxNumOfPixels == -1) && (minSideLength == -1)) {        return 1;    } else if (minSideLength == -1) {        return lowerBound;    } else {        return upperBound;    }}

}