img2bin

Extracts binary data from photos of calculator LCDs.

Requirements

• Python 3.x
• OpenCV for Python

Usage

1. Run python img2bin.py <fileName> <width> <height> in a console.

   • fileName should be a picture of LCD displaying the data you want to extract;
   • width is the pixel count of the width of the data area(if there's only a 96x31 area showing the data you want, type 96). This number must be a multiple of 8;
   • height is the pixel count of the height of the date area.

2. A window should pop up, asking you to select the corners from the picture you provided.

   • Read the text in the console to learn how to use this window to pick the corners;
   • I don't know how to do corner detection, that's why it's manual at this moment.

3. After comfirming the corners, another 2 windows should appear, showing parameter trackbars and transformation result.

   • Drag the trackbars to adjust the parameters;
   • Check the transformation result in another window;
   • If the result matches what you see in the photo, follow the tips in the console.

4. (New) Another 2 windows now appears, letting you to correct the transformation result manually.

   • Drag the trackbar to adjust the transparency of conversion result.
   • Click on a pixel to flip its color.
   • Follow the instruction in console to proceed.

5. Now you should get a file named out.bin in the directory, containing width*height/8 bytes of data extracted from the LCD picture.

   • If you chose to save the result, it will OVERWRITE the existing file! I hope you didn't store your bitcoin wallet in a file named out.bin.

Notes

• This piece of code runs okay with Windows 10, Python 3.8.9 and OpenCV 4.7.0 for Python. I didn't test it on any other system so I don't know if it works unmodified with other configurations.
• I don't know much Python/DSP/OpenCV things, most of the code in the file are copied from the Internet.
• No warranty of any kind is provided(despite it doesn't mess with the OS), use this at your own risk.