The extension GPD identifies files that contain bitmap images that have been compressed using the lossless method of RGB Light PhotoDefiner. This method uses an approach called "new light reference organization on triplet RGB" and LZMA compression.
The format is particularly suitable for graphic elements, such as logos or cartoons, with large color areas.
RGB Light provides a free Quicktime component for Windows and Mac OSX.
Most often resolving problems with opening GPD files is very simple. Just install an appropriate program that supports such files. All of the listed programs support GPD files, but may vary in offered function and purpose. Some programs may be capable only of viewing contents of GPD files or offer file conversion options, but may not be capable of editing such files.
It is possible that although a compatible program has been installed on user’s system, it is not used by the system to open it. This may happen because no default application was associated with this type of files. To associate GPD files with given application, select "Open with" from drop-down menu (accessed by right-clicking on the file). Then select from the list the program or application you want to be used to open this type of file. If the Microsoft Windows applications is not on the list, select "Browse" option in order to manually locate the directory where Microsoft Windows has been installed.
Sometimes problems with opening GPD files may not lie with the application itself, but can arise due to other causes, such as: