Ravens evidence — a picture that says more than it shows

The flag is hidden in the least significant bit of the pixel bytes, in order (row-major over the
RGB bytes), one character per 8 bits, most-significant bit first, ending at a null byte. Pull the
LSB of each byte, group into bytes, and read the ASCII. Tools like zsteg or a few lines of
Python with PIL do this. Format HTF{...}.