Great question :) Frequency analysis is actually still pretty useful for ciphers more complicated than a monoalphabetic substitution cipher. Take a polyalphabetic substitution cipher (similar to the one you described), where a key is used to determine the offset for each character. In this example the key is ABC:
At first glance, frequency analysis would be useless against this ciphertext. But if you can work out the key length (in this case, 3), you can group every 3rd character together and then perform frequency analysis on each group, as we know each group as been encrypted with the same key, making frequency analysis relevant again.
That's a great question! My original plan that once I had extracted all the items from the plate, the app would then detect the average colour of the remaining regions and "fill" the gaps - that wouldn't work well with plates that have different patterns, but would probably be good enough for plates of a single colour.
Due to time constraints (and ultimately solving the majority of the problems I had originally aimed to with this project), the app replaces the cropped circular region with a plain white plate (a separate image contained in the app) before placing the extracted items.
Maybe I'll go for the more advanced implementation if/when I spend more time on this project!
I'd love to see someone build this as a bookmarklet - I wouldn't know where to begin with image processing in JavaScript. Maybe a project for another day...
That's a great idea. If I could get the image processing to run fast enough, I'd love to get to a point where you could have Screentendo overlay a video (of a scrolling level for example), and have the level blocks generate as the video played.
Yeah I played around with building levels in TextEdit while I was developing the app - it's a lot of fun watching lines of text turn into platforms for Mario, and it allows for iterating on level design really quickly :)
That's great to hear, hope your kids enjoy. Thanks!