Right now I'm trying to whip up a test program and having issues with such a large tilemap and performance. I suppose that's more of a problem of the way the tilemap is set up and not the Perlin Noise object though.
So basically how it works is this, there are three settings that affect the detail of the map - Octaves and Frequency affect the quality, Amplitude affects the height ( -Amplitude to +Amplitude is the values that it gives out. ), and lastly, the seed. Basically, if you give it the same seed, it will give you the same noise...so the terrain isn't only random - it's persistent. So it can be used in an RPG or whatever and integrated into the save game, and there is no limit to how much terrain you can come up with, if you keep adjusting the seed.
The noise itself does not have a width and a height, but is percentage based. In other words, it doesn't think in terms of "X,Y", but more like "52% across the area, 32% down the area). I will set it up so that it uses layout coordinates, for simplicity, but the side effect of this is that, since it doesn't compute stuff in finite amounts, you can have a layout as large as you want, and the noise will still look good.
The "Water Level" you see in that screenshot, was just an arbitrary number chosen by me. Basically those are all one white sprite in an array paste. At layout start it runs all of them against the PerlinNoise object and colorizes them according to the amplitude that is output where they are at. I do a system comparison event on that, if it's under zero it's water, and above zero is land. The entire cap is two objects, six conditions, and four actions...and if I change the seed a completely different output is given, as expected.
I thought about making this into a "terrain" plugin, and integrating a lot of functionality specific to terrain, but perlin noise has applications unrelated to terrain, so I thought I'd keep it simple and let the cap designer use it how he wants to use it. I've wanted something like this in Construct *forever*. If and when someone else comes up with a Tilemap object - combined with this, we're talking the end of comparisons to MMS and Game Maker, because Construct will simply be a superior program.