Foto-Mosaik-Edda 

Foto-Mosaik-Edda can compose a poster out of multiple smaller photographs. It creates a very nice effect because the poster appears to be a single image if you look at it from a distance, but as you approach, you notice the tiles or tiny pictures that compose it. The application has a nice and intuitive interface. In fact, all you have to do is to run the wizard and select the desired options at each step.

You can start by creating one or various databases including the source photographs for your posters. Luckily, it supports various popular image formats. Compared with other similar tools, Foto-Mosaik-Edda has the advantage of allowing more control over the results. In this regard, it lets you choose one of four styles, including classic, parquet, chaos and detail. Unfortunately, the free version doesn’t permit trying other styles but classic. Then, you need to choose the base photograph. At this point, you can configure the number of tiles as well as how many times each photo in the database can be repeated. After setting your preferences, there isn’t much left to do but wait for the program to do its job. In case the number of source photos is not enough to form the complete poster, the program alerts you about that and decreases tile density automatically.

All in all, Foto-Mosaik-Edda does a great job in creating high-quality mosaics. It even has a built-in image viewer that allows using various zoom levels. However, since there are various similar tools out there, you may want to try a few of them before making a decision.