1. Open TOOLS on menu bar and click PAGE INFO.
2. PAGE INFO would pop out and click on MEDIA. on ADDRESS, scroll down and find any file with image TYPE. you can also check the image below on IMAGE PREVIEW.
3. if you've found the right image, click SAVE AS and SAVE IMAGE would pop up, so you can choose the location you wanna save in your computer. since the file usually on HTML TYPE, you have to change it to jpeg by choose ALL FILES on SAVE AS TYPE.
4. And don't forget to rename the FILE NAME by changing the .HTM to .JPG and then you can click SAVE.
PS: this procedure can also be implemented on other site, such as instagram, naver, daumblog, etc.
Thanks to Meikwang.tistory.com