Android如何压缩图片,而不读取内存?

时间:2016-04-29 03:29:41

标签: android image bitmap

我发现如果想要压缩图片,每个人都会先读取Bitmap。但是我不想阅读,只需编辑图片文件,然后图片文件可以更小。

java有类,但它不能用于android。有没有源代码可以做到这一点?

2 个答案:

答案 0 :(得分:0)

您可以使用Picasso Library进行图像处理。就像这样:

Picasso.with(getActivity())
                    .load(R.drawable.add_icon)
                    .resize(130, 130).placeholder(R.drawable.no_images).into(imgPratientImage;)

答案 1 :(得分:0)

试试这段代码。

public static int calculateInSampleSize(
        BitmapFactory.Options options, int reqWidth, int reqHeight) {
    // Raw height and width of image
    final int height = options.outHeight;
    final int width = options.outWidth;
    int inSampleSize = 1;

    if (height > reqHeight || width > reqWidth) {

        final int halfHeight = height / 2;
        final int halfWidth = width / 2;

        // Calculate the largest inSampleSize value that is a power of 2 and keeps both
        // height and width larger than the requested height and width.
        while ((halfHeight / inSampleSize) > reqHeight
                && (halfWidth / inSampleSize) > reqWidth) {
            inSampleSize *= 2;
        }
    }

    return inSampleSize;
}

使用以下代码从字节数组中获取图像

                BitmapFactory.Options options = new BitmapFactory.Options();
                options.inJustDecodeBounds = true;
                BitmapFactory.decodeByteArray(imageByteArray, 0, imageByteArray.length, options);
                // Calculate inSampleSize
                options.inSampleSize = calculateInSampleSize(options, WIDTH, HEIGHT);

                // Decode bitmap with inSampleSize set
                options.inJustDecodeBounds = false;
                bitmap = BitmapFactory.decodeByteArray(imageByteArray, 0, imageByteArray.length, options);
                int dimension = getSquareCropDimensionForBitmap(bitmap);
                bitmap = ThumbnailUtils.extractThumbnail(bitmap, dimension, dimension);

其中imageByteArray实际上是您可以从服务器获取的字节数组。你可以使用其他方法,我只写这个例子。变量WIDTHHEIGHT是图片的所需宽度和高度。