incorrect jpeg header

[elgorwi]

Nice testbench. However, ran into an issue when trying this out on my system.
The resulting jpeg is not recognised because of an incorrect header. It looks like the header.bin is read as a string rather than binary. Line 13 of interfaces.py should be changed as follows:

_jpeg_header = open("header.bin", "rb").read()

Or more pythonic:

with open("header.bin", "rb") as f:
    _jpeg_header = f.read()

With this change the testbench is running fine on my system