Open dialog is where you can load images into GIMP for viewing or editing. The left hand window shows the directories and the right hand window shows the files in the selected directory. To open a file, select it in the files listing then choose the correct file type. If the file has an extension which defines its filetype (such as .xcf) you can select Automatic and GIMP will open the file in that format. Alternatively, you can force GIMP to open the file as a specific format by choosing one of the other options in the drop down list.
Some images have a preview associated with them so you can see what the image is before opening it. This is particularly useful for larger images where opening the full image will take a while. If an image doesn't have a preview, you can click Generate Preview to create one. This preview image is stored in a sub-directory of the current one called .xvpics. This preview image will be used in the future when using the open dialog. Clicking OK opens the image with the selected settings; Cancel aborts.
A useful feature of the Load Image dialog is autocompletion of file names. Type the first few letters of the file name and press the Tab key. GIMP will then complete as much of the file name as is uniquely defined by what has already been typed. The right side of the dialog will display all files that match the letters in the selection box. You can then type more letters and press Tab again to update the window.
You can load multiple images by pressing Shift and clicking on each file you want to open.
Default Keyboard Shortcut: Ctrl-O