Android图片操作-合并图片

/**
     * 将多个Bitmap合并成一个图片。
     * @param columns  将多个图合成多少列
     * @param bitmaps 要合成的图片
     * @return
     */
    public static Bitmap combineBitmaps(int columns, Bitmap... bitmaps) {
        if (columns <= 0 || bitmaps == null || bitmaps.length == 0) {
            throw new IllegalArgumentException(
                    "Wrong parameters:columns must > 0 and bitmaps.length must >0.");
        }
        int maxWidthPerImage = 0;
        int maxHeightPerImage = 0;
        for (Bitmap b : bitmaps) {
            maxWidthPerImage = maxWidthPerImage > b.getWidth() ? maxWidthPerImage
                    : b.getWidth();
            maxHeightPerImage = maxHeightPerImage > b.getHeight() ? maxHeightPerImage
                    : b.getHeight();
        }
        int rows = 0;
        if (columns >= bitmaps.length) {
            rows = 1;
            columns = bitmaps.length;
        } else {
            rows = bitmaps.length % columns == 0 ? bitmaps.length / columns
                    : bitmaps.length / columns + 1;
        }
        Bitmap newBitmap = Bitmap.createBitmap(columns * maxWidthPerImage, rows
                * maxHeightPerImage, Config.RGB_565);
        for (int x = 0; x < rows; x++) {
            for (int y = 0; y < columns; y++) {
                int index = x * columns + y;
                if (index >= bitmaps.length) {
                    break;
                }
                newBitmap = mixtureBitmap(newBitmap, bitmaps[index],
                        new PointF(y * maxWidthPerImage, x * maxHeightPerImage));
            }
        }
        return newBitmap;
    }