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I just learned to use hex editors and i have a question:
If i change 1 or some of hex values of a file(picture) and save it, Is there a way to find changed hex values an make original file back?

enter image description here

John Deters
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hamedb71
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    This question is off-topic here. Maybe the people on superuser.com can help you when you would tell them what editor you are actually using. – Philipp Nov 13 '14 at 09:21

2 Answers2

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You can edit anything you want with a hex editor. There are ways to "hide" entire files but as soon as you can make them visible and open with a hex editor, then there are no ways to make parts of a file invisible

The main thing in editing image means you need to work within the frame of what you are changing. Suppose you edit a simple BMP image, and you "change" its size from 10x10 to 20x20. Will it "work"? No - you are changing the image size but not the actual image, and no program can read your modified BMP image anymore, since it expects a 20x20 image now.

However, if you only change the color of the one pixel inside the image, then there is no problem. BMP files do not contain a checksum, and so your altered file will be read correctly.

user3315780
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The numbers on the left and top are the address of the byte. Just go to the same address and change it back again.

PS: You could avoid all this hassle if you just save and restore a backup of the file

drpexe
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  • No...I mean if i edit a picture hexes, it can't be seen.Can someone else (a hacker) be able to see original picture? – hamedb71 Nov 13 '14 at 11:00
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    if you are thinking about hiding information this way. please dont! it's a really bad way of doing this. try using encryption instead. – drpexe Nov 13 '14 at 13:42