Gerber Format (GBR)
The Gerber file format is a vector – based format used by GerbTools, ViewMate and CamTastic as a simple way of transferring printed circuit board information to a wide variety of devices. The Extended Gerber Format (RS-274X) handles information for defining shapes and sizes of lines and other features. This format supports Polygons, Circles, Ovals, Outlines, Arcs, Lines, Rectangles, Moire and Thermal.
For Gerber files, you can read the following bits per pixel: 24.