frex / binarypic

Convert a binary to greyscale PNG to judge how noisy it is

binarypic

Small program to convert a binary file to grayscale 1-byte-1-pixel png and back using stb_image and stb_image_write.

To allow for converting back the image is padded to a rectangle with some pixel that is different value than last valid one (so the decoding can strip it). Even images of 'nice' size like 16 byte binary file that'd be a 4x4 image with no padding will be padded so decoder always knows that all trailing pixels of same value are padding and not data. This allows for a byte perfect roundtrip.

The idea for this program appeared when I ran across a multi-meg file that had most of its bytes set to 0 but due to its size even tiny font and a fullscreen hex viewer weren't enough to show it. An image generated by this program would make such large swathes of 0s or other patterns easy to see at a glance.

Example of image generated from exe of this very program:

Go to releases to download a Windows exe compiled with Pelles C with no -O2 to avoid running into any -O2 optimizer bug similar to this one that affected stb_image: Pelles C forum bug report