A tool to view and edit Minecraft maps.
To load maps, select a folder containing Minecraft map file. Map files file names use the format map_<id>.dat, so e.g. map_15.dat is a valid map file name.
Minecraft usually stores map files in a world's data folder.
Left-click on one of the map files in the list view on the left side to open it. Once a change has been made, you can not switch to a different map file until it has been saved or reloaded. An unsaved map file has a * next to its name.
To add a banner to the map, right-click anywhere on the map. A banner's color can be changed by right-clicking on the banner and then selecting a new color. When clicking the red cross, the banner is deleted. The banner's text can be changed by right-clicking on its text. The text is always saved in JSON format.
You might wonder: Why the hell does it support banners, but not the fancy other icons like on treasure maps you can acquire from Cartographers? The answer is that those icons are unfortunately not saved in the map file, but per-item in the minecraft world files. You may want to look at MCA Selector to edit them.
When a map file has been loaded, a custom image can be imported and squeezed into the Minecraft's map format.