What is GDI?
GDI stands for Graphic Device Interface is a programming interface used by Microsoft Windows as representation for graphics. GDI is mainly utilized by Windows to send out pictures and text to the computer screen or printers for display purposes. Specifically, GDI is tasked to display curves and lines, draw closed figures, show text and bitmap images, handle color palettes, and render a variety of fonts.

But aside from its use in displaying drawings or graphics representation, GDI is also capable of scaling and abstraction of various target computer hardware devices. This means that through GDI, graphic representations or drawings may be displayed on multiple hardware devices simultaneously and properly. This is done by employing its component methods and classes such as images, fonts, and 2D vector graphics.

GDI is present in all Windows operating system versions. Starting with Windows XP’s release, GDI was replaced with GDI+ which added more features and functionality to the graphics display and representation. These features include anti-aliasing of 2D graphics, increased complexity in path management, gradient shading capabilities, increased support for newer graphic file formats such as PNG and JPG, and the use of ARGB values to display color. By the time Windows Vista was released, GDI and/or GDI+ are initialized through the Desktop Windows Manager. This allows for faster window moving and increased window responsiveness. Windows 7 meanwhile has an even more improved GDI system application with the Desktop Windows Manager allowing for optimal computer performance in terms of graphics applications through the use of localized memory for compositing. This process also results to a decrease in system memory footprint.

GDI is also a feature of Windows Embedded CE and they are designed and developed specifically for computer devices that have low system resources. Though it may not have all the graphical functions found on Windows OS in desktop versions, the Windows Embedded CE GDI is still very powerful and able to display full-color graphics.