If you open an EPS file in a program such as Photoshop, the file will be “rasterized” (flattened) and uneditable, similar to any JPEG file. While most applications can generate EPS files, the only editable benefit you will receive is if the file was originally created as a vector image.
by Gina Trapani
Photo by Robbie Gates used with permission
Click to viewRemember those invisible ink kits from when you were a kid? You'd write a secret message that no one could see unless they had a black light or the decoder marker. The digital equivalent of invisible ink is steganography software, apps that embed files and data inside other files, hidden from everyone who doesn't know any better.
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You don't have to be a trained spy plotting international espionage to put steganography to good use. With some free tools for both the Mac and PC, you can embed secret information in image, PDF, HTML and MP3 files for fun or profit.
Why stego?
Unlike encryption, which obscures data in such a way that it's obvious someone's keeping something from listeners-in (and therefore heightens interest in that info), stego techniques offer no hint to the outsider that there's any private data contained within the visible file. Like hiding your valuables from burglars in an empty cereal box in your kitchen cabinet, steganography keeps the existence of the secret item from everyone but those in the know.
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In fact, right here in this Lifehacker logo image, there's a message hidden for you:
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Here's how to go about decoding it.
Hide in Picture (Windows)
The free Hide in Picture (Windows only) embeds files into GIF or BMP images, and lets you set a password to retrieve the hidden file. The Hide in Picture interface is barebones, as you can see:
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Use Hide in Picture to decode the message hidden in the image above. (Hint: the password is lhacker.)
Other free Windows tools offer more filetype support. wbStego can encode and decode files in PDF's, HTML files or bitmaps. mp3stego embeds text inside MP3 files (command line and GUI interface available.) Here are more Windows stego software options [via Webby's World]. Be warned: while all of these tools work, none of them will win awards for being good-looking.
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Pict Encrypt (Mac)
Similarly, the free Pict Encrypt (Mac only, thanks, Mirko!) adds text to GIF, JPEG, TIFF, PNG and MacPICT images, locks it with a password, and saves the file with hidden data as a PICT file. Its interface is a simple, barebones wizard that leads you through the encrypt and decrypt process. One difference between Pict Encrypt and Hide in Picture is that you don't embed another file; you actually enter your secret text into the Pict Encrypt wizard, as shown.
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Pict Encrypt's text editor is pretty low level; some text navigation keys like Cmd-right arrow don't work, so be prepared.
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Command line - cat your gif and zipWhat Programs Can Read Text Within Jpg Files For Mac Free
Finally, for those of you comfortable on the command line, reader Jason H. writes in with a nifty stego trick using built-in tools. The premise of this technique is to append a .zip file to the end of a .gif file, resulting in a file which is readable by both .gif programs and .zip programs.
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Jason explains why this works (with the help, he says, from a long-lost thread at Something Awful):
It works because .gif files keep all of their information in the headers, while .zip files keep them in the footer. Since that's the case, .gif viewers read from the front of the file, while .zip readers read from the end.
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Here's how to combine your .gif and .zip. At the Windows prompt use this command:
copy /B source.gif+source.zip target.gif
Or in Linux/Mac:
cat somefile.zip >> somefile.gif
The problem with this method is that not all zip programs can extract the resulting file. When I tried, both 7-Zip and Windows built-in extraction failed, but WinRAR handled it just fine. Still, that's something the intended recipient should know.
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How to create and extract.rar files
Tech help site Of Zen and Computing breaks down how to deal with the (fairly unusual) compressed…
Read more Read
For double super-duper security, password the zip file that you hide inside the image. WinRAR and 7-Zip both let you add passwords to a zip archive.
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Alternative Text Images should be given appropriate in PowerPoint. Microsoft powerpoint 11 mac alt text for graphics.
Uses for stego
So now that you know how to hide files in files, why would you do it? Here are a few uses for stego:
Got any tales of steganographical goodness? Let us know in the comments. Now, go forth and have fun with your new invisible ink, ya big sneak.
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Thanks to Lifehacker contributor Jason Thomas for introducing us to the concept of stego and to Lifehacker guest editor Joe Anderson for his post rounding up stego tools.
Gina Trapani, the editor of Lifehacker, fancies herself a super-secret spy. Her semi-weekly feature, Geek to Live, appears every Wednesday and Friday on Lifehacker. Subscribe to the Geek to Live feed to get new installments in your newsreader.
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Related Articles
You can use many methods to add captions to images, particularly if you add the images to a publishing medium, such as Web pages, rich text documents or presentations. However, if the JPEG image is removed from the source, the caption will likely be lost. If you want your JPEG file to be independently distributable with its caption intact, add the caption directly onto the image. Windows 7 users already have the capabilities to do this with the included Paint program.
1.
Click the 'Start' button, 'All Programs,' 'Accessories' and 'Paint.'
Hold the 'Ctrl' button and press 'O' to invoke the Open navigation menu.
3.
Click the JPEG file in the Open navigation menu and click 'Open.'
4.
Click the 'A' in the Image group of the Home tab.
5.
Click wherever you want the text to appear on the image. This creates a text box and opens up the text options at the top of the window.
6.
What Programs Can Read Text Within Jpg Files For Mac
Select the font, font size and effects, such as bold, italic or underline, in the Font group of the Text options.
7.
Click 'Opaque' or 'Transparent' in the Background group to make the text's background a solid color or invisible.
8.
Click 'Color 1' or 'Color 2' and click the color you want from the Colors pallet, or click 'Edit Colors' for more options. Color 1 affects the text color. Color 2 affects the background color and only applies if the background is opaque.
10.
Click anywhere on the image to exit the text box and make your changes final. If you aren't satisfied with the results, press 'Ctrl-Z' to undo your changes and start over.
Tip
Photo Credits
Choose Citation Style
Taylor, C. 'How to Add a Caption Directly Onto a Picture in a JPEG File.' Small Business - Chron.com, http://smallbusiness.chron.com/add-caption-directly-onto-picture-jpeg-file-28671.html. Accessed 07 September 2019.
Taylor, C. (n.d.). How to Add a Caption Directly Onto a Picture in a JPEG File. Small Business - Chron.com. Retrieved from http://smallbusiness.chron.com/add-caption-directly-onto-picture-jpeg-file-28671.html
Taylor, C. 'How to Add a Caption Directly Onto a Picture in a JPEG File' accessed September 07, 2019. http://smallbusiness.chron.com/add-caption-directly-onto-picture-jpeg-file-28671.html
Note: Depending on which text editor you're pasting into, you might have to add the italics to the site name.
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