100a - PeekAText

Type or paste what you wish to hide.
Save the new, unsuspecting photo. Or send it to someone else.
Select 'Scan' to reveal hidden text
Tada!

Inspiration

Do you have annoying friends/family who loves to read your text/notes? Ever wanted to find a place to hide your notes on your smartphone? PeekAText is the perfect convenient solution for you.

What it does

PeekAText using steganography techniques to encode text into a pre-existing image and is able to retrieve the hidden text in a reverse process.

How we built it

PeekAText is built natively with Swift in Xcode.

Challenges we ran into

We need to retrieve pixel data for each pixel and that is a time-consuming and computationally slow task. We managed to reduce the computational power needed by using pointers on the go rather than load the entire bitmap to memory. On the fly calculation also allows us to only load the portion of the image that needs to be modified, greatly reducing computation time.

Accomplishments that we're proud of

Reducing computation time needed for encoding/decoding.

What we learned

UIImage handling of PNG is not fully lossless hence leading to many problems along the way. We learnt how to tip-toe around the problem and achieve encoding/decoding even with minor loss of information.