Remove Exif info in jpg image under command line

Exif, stands for Exchangeable image file format, which we usually use to recognize the camera manufacturer, model, exposure time in a digital photo, it is a standard that specifies the formats for images, sound, and ancillary tags used by digital cameras (or digital devices in nowadays, like smart phones and tablets), scanners and other systems handling image and sound files recorded by digital cameras.


Exif in JPEG image example from Wikipedia:

Exif can help us know more about the photos and audios, but may also leaks the valuable and privacy info if you don’t want to let others know that you just want to share pictures with others, it will also cost a small disk space, but uf you don’t need it or you don’t want it, it’s also a waste of disk space, so you may want to remove that info like me in some situation. Here is the steps to remove Exif under command line.

Install exiftool:

Make sure you can now use exiftool:

If you would like to see the current exist info, use this command, filename.jpg is the picture you want to manipulate:

Now you can remove Exif info:

By default, it will backup your file to filename_oringinal, like filename.jpg -> filename.jpg_original, so you don’t need to worry about the backup, if you don’t want it, you can also add parameter -overwrite_original to prevent to backup file been generated.

After you remove the Exif info, you will find the modified file be a little bit smaller now.

If you take a look at its info, you will find that there are only some basic info remaing:

That’s all.

常用 Public DNS resolver 清單整理 (IPv4)

目前還沒有常在使用 IPv6, 這邊只列 IPv4 的 Public DNS,通常 DNS 會優先選用 ISP 所提供的,再把這些 DNS 當作備援使用,或是 ISP 提供的素速度太慢了就會另外找一些速度比較快的替代方案,而這些 DNS 多半強調能提供更快速以及更可靠的解析,以及宣稱保護使用者的隱私、或提供像是惡意網站或是成人網站過濾等功能,在你連到該網站前就已經先幫你作過濾,詳細資訊可以參考該 DNS 官方提供的資訊

Public DNS — Google Developers

  • — the Internet’s Fastest, Privacy-First DNS Resolver (Cloudflare)


OpenDNS IP Addresses | OpenDNS,Open DNS 提供兩種方案,Family Shield 的那兩組是多了成人網站阻擋: