Android 图片缩放

Posted 2020-08-11

通过计算图片缩放值进行图片缩放

 /**
     * 根据路径获得突破并压缩返回bitmap用于显示
     *
     * @param filePath
     * @return
     */
    public static Bitmap getSmallBitmap(String filePath, int width, int height) {
        final BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(filePath, options);

        // Calculate inSampleSize
        options.inSampleSize = calculateInSampleSize(options, width, height);

        // Decode bitmap with inSampleSize set
        options.inJustDecodeBounds = false;

        return BitmapFactory.decodeFile(filePath, options);
    }

计算图片的缩放值

/**
     * 计算图片的缩放值
     *
     * @param options
     * @param reqWidth
     * @param reqHeight
     * @return
     */
    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) {

            // Calculate ratios of height and width to requested height and
            // width
            final int heightRatio = Math.round((float) height
                    / (float) reqHeight);
            final int widthRatio = Math.round((float) width / (float) reqWidth);

            // Choose the smallest ratio as inSampleSize value, this will
            // guarantee
            // a final image with both dimensions larger than or equal to the
            // requested height and width.
            inSampleSize = heightRatio < widthRatio ? heightRatio : widthRatio;
        }
        HcLog.D("HcUtil #calculateInSampleSize = " + inSampleSize);
        return inSampleSize;
    }