The following image provides some more info about the controls in the sidebar:
The controls in the topbar are for creating/altering labels. Most of the controls should be obvious, but here are a few notes:
Mouse - This has nothing to do with labels. This is the mouse position in the current view in image coordinates.
Show - Show/hide an individual label.
Show All - Show/hide all labels.
X, Y - Pixel location of top left corner of label.
Font - List of available true type fonts found on the computer. By default, the program searches, "/usr/share/fonts",
"/usr/local/share/fonts", and "~/.fonts". The search is recursive. Additional font paths can be added to the config file.
Size - Font size in pixels
FG/BG Color - Select color of text and color of background or none. Clicking the entry field of the combo box calls up a
color select dialog for customizing colors.
All - There are several buttons called "All". They are used to apply a setting to all the labels.
The program remembers settings such as size and placement of windows, source and destination directories for images,
most recently used font parameters and layout parameters, etc.
Images can be rotated when loading.
The program does not preserve EXIF data.