The Image drag-and-drop branch under Configuration - Editor has the following options:
Insert link to images when dragged-and-dropped into web file
If this option is selected, images may be added to web files as HTML or CSS code using one of three methods:
By dragging and dropping the image file(s) from Windows Explorer
By dragging and dropping the image file(s) from the File View (Explorer or Project pane)
By double-clicking the image file(s) in the File View (Explorer or Project pane)
This feature keys off the active file's highlighting type, and will only work for web-based languages (HTML, Javascript, Perl, PHP, VBScript, XML, CSS). The following file extensions are supported for this operation: BMP, GIF, ICO, JPEG, JPG, PNG, SVG, TIFF.
If this option is not selected, image files opened via any of the methods described above will be opened in the editor in hex mode.
Format
The Format text fields may be used to define the default string to be used when inserting the image into web-based files. Clicking on the "?" button will show a list of valid image format variables. These may be used when constructing the default image string.
Note: If the CTRL key is pressed while dragging an image file from Windows Explorer and dropping it into a web-based file in the editor, an Insert image(s) / customize dialog will be shown. This dialog may be used to customize the inserted image string for the current operation only. This does not affect the default format string defined in Configuration.
HTML
This field is used to define the string to be used when inserting an image string into web-based files.
CSS
This field is used to define the string to be used when inserting an image string into CSS sections of web-based files.