pdvrdt

CLI tools to hide (pdvin) or extract (pdvout) any file type via a PNG image.
You can post your image with hidden data on *X/Twitter and a few other social media sites.

*Image size limits (cover image + data file):

• Flickr (200MB), ImgBB (32MB), PostImage (24MB), Reddit (19MB / -r option)
• Mastodon (16MB / -m option), ImgPile (8MB), *X/Twitter (5MB + Dimension limits)

Demo Videos: Hidden_JPG / Web_Tool

To post file-embedded PNG images on Mastodon, you need to use the -m option.

To post file-embedded PNG images on Reddit, you need to use the -r option.

From the Reddit site, always select the "Images & Video" tab/box to post your image.

When saving an image from Reddit, use new.reddit.com. Click the image in the post to expand it, then save it.
(Make sure you see the filename with a .png extension in the address bar of your browser, before saving.)

As well as the 5MB image size limit, X/Twitter also has dimension size limits.

PNG-32/24 (Truecolor) 900x900 Max. 68x68 Min.
PNG-8 (Indexed-color) 4096x4096 Max. 68x68 Min.

When saving an image from X/Twitter, always click the image first to fully expand it, before saving.

Compile and run the programs under Windows or Linux.

(You can try pdvrdt from this site if you don't want to download & compile the source code.)

Usage (Linux - pdvin / pdvout)

user1@linuxbox:~/Downloads/pdvrdt-main/src/pdvin$ g++ main.cpp -O2 -lz -s -o pdvin
user1@linuxbox:~/Downloads/pdvrdt-main/src/pdvin$ sudo cp pdvin /usr/bin

user1@linuxbox:~/Desktop$ pdvin 

Usage: pdvin [-m|-r] <cover_image> <data_file>  
       pdvin --info

user1@linuxbox:~/Desktop$ pdvin rabbit.png document.pdf
  
Saved PNG image: prdt_17627.png 1245285 Bytes.

Complete!

You can now post your file-embedded PNG image to the relevant supported platforms.

user1@linuxbox:~/Downloads/pdvrdt-main/src/pdvout$ g++ main.cpp -O2 -lz -s -o pdvout
user1@linuxbox:~/Downloads/pdvrdt-main/src/pdvout$ sudo cp pdvout /usr/bin

user1@linuxbox:~/Desktop$ pdvout

Usage: pdvout <file_embedded_image>
       pdvout --info
        
user1@linuxbox:~/Desktop$ pdvout prdt_17627.png

Extracted hidden file: document.pdf 1016540 Bytes.

Complete! Please check your file.

Issues:

• Reddit - While you can upload PNG images via the mobile app, you need to use the Desktop/browser to download them via new.reddit.com.
• ImgPile - You must sign in to an account before sharing your data-embedded PNG image on ImgPile.
  Sharing your image without logging in, your embedded data will not be preserved.

My other programs you may find useful:-

• pdvzip: CLI tool to embed a ZIP file within a tweetable and "executable" PNG-ZIP polyglot image.
• jdvrif: CLI tool to encrypt & embed any file type within a JPG image.
• imgprmt: CLI tool to embed an image prompt (e.g. "Midjourney") within a tweetable JPG-HTML polyglot image.
• jzp: CLI tool to embed small files (e.g. "workflow.json") within a tweetable JPG-ZIP polyglot image.
• pdvps: PowerShell / C++ CLI tool to encrypt & embed any file type within a tweetable & "executable" PNG image