為了符合 sm.ms 的上傳限制，我需要壓縮圖片再上傳，然後就找到了個可以批量處理且有 linux build 的項目：
Caesium is an image compression software that helps you store, send and share digital pictures, supporting JPG, PNG, WebP and TIFF formats. You can quickly reduce the file size (and resolution, if you want) by preserving the overall quality of the image.
挺好用的，基本上可以壓縮一半以上：