README.md

README.md

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 # FileImgSwap
 
+<p align='center'>
+<a href=README.md>中文</a> | <a href=README_EN.md>EN</a>
+</p>
 **[FileImgSwap](https://github.com/fzxx/FileImgSwap) 文图变**是一款可以把文件与 PNG 图像进行互转的工具，支持加密、图种（附加压缩包）功能，可将任意文件隐藏在 PNG 图像中，也能从生成的 PNG 图像中还原出原始文件。
 
 ![](FileImgSwap.gif)

README_EN.md

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+# FileImgSwap
+
+<p align='center'>
+<a href=README.md>Chinese</a> | <a href=README_EN.md>EN</a>
+</p>
+**[FileImgSwap](https://github.com/fzxx/FileImgSwap)** is a tool that enables mutual conversion between files and PNG images. It supports encryption and image-seed (appending compressed packages) functions, allowing you to hide any file in a PNG image and restore the original file from the generated PNG image.
+
+![](FileImgSwap.gif)
+
+## Features
+
+- **File to PNG**: Convert any type of file (such as text, documents, compressed packages, etc.) into a PNG image, with file data encoded into the image's pixels.
+- **PNG to File**: Extract and restore the original file from a PNG image generated by this tool.
+- **Encryption Protection**: Encryption protection via a password/key file with the **same name as the main program in the same directory**.
+- **Image-seed Function**: Append a compressed package to the end of the generated PNG image to achieve the "image-seed" effect.
+- **Metadata**: The image retains the original file's name and modification time.
+
+## Technical Details
+
+- Encryption algorithm: AES-CTR
+- Key algorithm: Key derivation using PBKDF2-SHA256 and HKDF-SHA256
+- Image format: PNG
+
+## User Guide
+
+Drag and drop files/folders onto the program icon, or run via the command line.
+
+#### File to PNG
+
+Convert ordinary files to PNG images:
+```bash
+# Convert a single file
+FileImgSwap file.pdf
+
+# Convert multiple files
+FileImgSwap image.jpg data.zip notes.txt
+```
+
+A PNG file with the `.fis.png` extension will be generated after conversion. For example, `document.pdf` will generate `document.fis.png`.
+
+#### Restore File
+
+Restore the original file from a PNG image:
+```bash
+# Restore a single PNG
+FileImgSwap file.fis.png
+
+# Restore multiple PNGs
+FileImgSwap file1.fis.png file2.tz.png
+```
+
+The restored file will use the original file name. If a file with the same name exists, it will be automatically renamed (with a sequence number added).
+
+#### Encryption Function
+
+To enable encrypted conversion, **create one of the following files in the same directory as the program** (both can also exist):
+- Password file: `.fisp.txt` with the same name as the program (e.g., `FileImgSwap.fisp.txt`), where the first line is the password.
+- Key file: `.fisp.key` with the same name as the program (e.g., `FileImgSwap.fisp.key`), which stores the binary key.
+
+The program will automatically detect and use these files for encryption/decryption. **No encryption will be applied if none are detected**.
+
+#### Image-seed Function
+
+Use the `-append` parameter to append a compressed package (zip/rar) to the end of the generated PNG. **Separation is not supported**; extraction requires a compression tool.
+```bash
+FileImgSwap video.mp4 -append archive.zip
+```
+
+The generated file will have the `.tz.png` extension. It can be viewed as a normal image and also extracted as a compressed package (zip/rar formats are recommended; rename the extension and use WinRAR for extraction).
+
+## Changelog
+
+[Changelog](CHANGELOG.md)
+
+## Notes
+
+- Encrypted files can only be restored using the **same password/key file**.
+- File-Image Swap + image-seed compressed packages can be encrypted with different passwords to achieve "one image, two decryptions".
+- 32-bit programs support a maximum single file size of 2GB, and 64-bit programs support a maximum single file size of 5GB.
+
+## Related Projects
+
+[XiangYue - Text encryption for free expression](https://github.com/fzxx/XiangYue)
+
+[NaughtyDamagePack - Make compressed packages look corrupted](https://github.com/fzxx/NaughtyDamagePack)
+
+## Download Link
+
+https://github.com/fzxx/FileImgSwap/releases