今天的問答環節由SuperUser提供，這是Stack Exchange的一個細分，Stack Exchange是一個社區驅動的問答網站分組。
I made a worrying discovery that after cropping a screenshot in Word, PowerPoint, and likely other Microsoft Office programs, the unused parts of cropped screenshots are retained. This has made me fairly paranoid as I frequently take screenshots and crop them to show the relevant piece of information before sending the documents off to others.
I had assumed that when I saved a document, the unused portions of cropped images were discarded, but looking at work from years ago, I can still uncrop the unused parts of the images to view the original screenshots in their entirety.
Is there a way to disable this? This seems like a ridiculous security flaw.
Delete Cropped Areas of a Picture
Even after you crop parts of a picture, the cropped parts remain as part of the picture file. You can reduce the file size by removing the croppings from the picture file. It is also a good idea to do this to help prevent other people from viewing the parts of the picture that you have removed.
Important: This cannot be undone. Therefore, you should only do this after you are sure that you have made all the crops and changes that you want.
1. Click the picture or pictures that you want to discard unwanted information from.
2. Under Picture Tools, on the Format tab, in the Adjust group, click Compress Pictures.
Note: If you do not see the Picture Tools and Format tabs, make sure that you selected a picture. You might have to double-click the picture to select it and open the Format tab.
3. Under Compression Options, select the Delete cropped areas of pictures check box. To remove croppings for the selected picture or pictures only and not all of the pictures in the file, select the Apply only to this picture check box.
Tip: For more information about reducing the file size of the pictures and compressing pictures, see Reduce the file size of a picture.
Source: Delete cropped areas of picture (Crop a picture or a shape with a picture fill) – Microsoft