[Jacob]

I hide my messages in pixels decrypt my picture and i will give you free VPN account.

send me? DD

[Frooxius]

Yes, these are easy to use for a human, however, they're also extremely easy to crack and decipher, especially with use of computers, so it's not very safe solution.

I would say that it's rather a encryption method, than language, as it doesn't change the actual language of the original message, but rather transforms the way it is expressed.

...ascii character codes, unicode character codes...

ASCII and Unicode actually have same codes for ASCII characters (English alphabet + most common symbols), so they would result in same codes, unless he would use also some foreign and extra characters, which is very improbable scenario, unless he would communicate using a foreign alphabet.

Because I believe that it's important to provide a rational reason for my statements, I am obligated to provide this further explanation: Unicode was designed in a way so it's backwards compatible with ASCII (especially UTF-8, which is the most commonly used now), that way, existing ASCII text can be still processed by software that uses UTF-8 without any conversions taking place. UTF-8 uses a single-byte values for ASCII set and adds more bytes as needed for characters with higher codes, producing a variable length code, but like I said, for ASCII subset, Unicode and ASCII are identical in their character codes.