NativeUtil.java 文件源码

/**
 * 4.尺寸压缩（通过缩放图片像素来减少图片占用内存大小）
 *
 * @param bmp
 * @param file
 */

public static void sizeCompress(Bitmap bmp, File file) {
    // 尺寸压缩倍数,值越大，图片尺寸越小
    int ratio = 8;
    // 压缩Bitmap到对应尺寸
    Bitmap result = Bitmap.createBitmap(bmp.getWidth() / ratio, bmp.getHeight() / ratio, Config.ARGB_8888);
    Canvas canvas = new Canvas(result);
    Rect rect = new Rect(0, 0, bmp.getWidth() / ratio, bmp.getHeight() / ratio);
    canvas.drawBitmap(bmp, null, rect, null);

    ByteArrayOutputStream baos = new ByteArrayOutputStream();
    // 把压缩后的数据存放到baos中
    result.compress(Bitmap.CompressFormat.JPEG, 100, baos);
    try {
        FileOutputStream fos = new FileOutputStream(file);
        fos.write(baos.toByteArray());
        fos.flush();
        fos.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}