android 图片压缩

小鱼儿 2022-05-23 10:55 246阅读 0赞

大致思路，根据后台上传图片限制，自己对图片进行处理

一般后台会限制图片宽高，对于超出限制的图片要进行宽高比压缩(减少图片的宽高) 核心代码

BitmapFactory.Options op = new BitmapFactory.Options();
            op.inJustDecodeBounds = true;//只读大小，不读数据
            BitmapFactory.decodeFile(path, op);
            int height = op.outHeight;
            int width = op.outWidth;
      LogUtil.e("scal_from_size" + outputFile.length() + "宽度为" + height + "高度为" + height, PhotoUtil.class);
      Bitmap bitmap = null;
      while (height > maxHeight || width > maxWidth) {// 如果宽度大的话根据宽度固定大小缩放
                    double scaleH = (float) height / maxHeight;
                    double scaleW = (float) width / maxWidth;
                    options.inSampleSize = (int) Math.ceil(Math.max(scaleH, scaleW)); // 1表示不缩放
                    bitmap = BitmapFactory.decodeFile(outputFile.getPath(), options);
                    LogUtil.e("宽度压缩后 宽度为" + options.outWidth + "高度为" + options.outHeight +
                            "scal_ok_size" + outputFile.length(), PhotoUtil.class);
                }

当图片大小大于服务器限制大小时就要进行质量压缩

try {
        while (fileSize >= fileMaxSize) {
      //如果图片大小 > 服务器要求大小
            options.inJustDecodeBounds = false;
            bitmap = BitmapFactory.decodeFile(path, options);
            fos = new FileOutputStream(outputFile);
            quality -= 10;
            bitmap.compress(Bitmap.CompressFormat.JPEG, quality, fos);
            fos.close();
            fileSize = outputFile.length();
            LogUtil.e("采样率压缩后 宽度为" + options.outWidth + "高度为" + options.outHeight
                    + "scal_ok_size" + outputFile.length(), PhotoUtil.class);
        }
    } catch (IOException e) {
        // TODO Auto-generated catch block e.printStackTrace();
    }

全部代码

static final int maxHeight = 1023;
        static final int maxWidth = 2047;
        static long fileMaxSize = 1024 * 1024;
        
        /**
         * 压缩图片
         *
         * @param path 图片地址
         * @return 压缩后的图片地址
         */
        public static File scal(String path, int scalSize) {
            
            File outputFile = new File(path);
            long fileSize = outputFile.length();
            long fileMaxSize = scalSize;
            BitmapFactory.Options op = new BitmapFactory.Options();
            op.inJustDecodeBounds = true;
            BitmapFactory.decodeFile(path, op);
            int height = op.outHeight;
            int width = op.outWidth;
            LogUtil.e("scal_from_size" + outputFile.length() + "宽度为" + height + "高度为" + height, PhotoUtil.class);
            Bitmap bitmap = null;
            if (fileSize >= fileMaxSize || height > maxHeight || width > maxWidth) {
                BitmapFactory.Options options = new BitmapFactory.Options();
                while (height > maxHeight || width > maxWidth) {// 如果宽度大的话根据宽度固定大小缩放
                    double scaleH = (float) height / maxHeight;
                    double scaleW = (float) width / maxWidth;
                    options.inSampleSize = (int) Math.ceil(Math.max(scaleH, scaleW)); // 1表示不缩放
                    BitmapFactory.decodeFile(outputFile.getPath(), options);
                    LogUtil.e("宽度压缩后 宽度为" + options.outWidth + "高度为" + options.outHeight + "scal_ok_size" + outputFile.length(), PhotoUtil.class);
                }
                FileOutputStream fos = null;
                int quality = 100;
                try {
                    while (fileSize >= fileMaxSize) {//如果图片大小 > 服务器要求大小
                        options.inJustDecodeBounds = false;
                        bitmap = BitmapFactory.decodeFile(path, options);
                        fos = new FileOutputStream(outputFile);
                        quality -= 10;
                        bitmap.compress(Bitmap.CompressFormat.JPEG, quality, fos);
                        fos.close();
                        fileSize = outputFile.length();
                        LogUtil.e("采样率压缩后 宽度为" + options.outWidth + "高度为" + options.outHeight
                                + "scal_ok_size" + outputFile.length(), PhotoUtil.class);
                    }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            return outputFile;
        }