Currently, consumer digital cameras are available which capture both still digital images and motion video images. The images are compressed by the digital camera and stored as still image files and motion video files using a digital memory, such as a Flash EPROM memory card. The image files are then transferred to a computer where they can be viewed, archived, or sent to others via email.
To select images, software application programs on the computer normally provide a “navigation” display, such as a user interface display screen having many small “thumbnail” images arranged in rows and columns, where each thumbnail represents an image file. For still images, a reduced size version of the still image is used as the thumbnail. For video files, it is normal to use the first image of the video sequence to represent the video file. Once the user selects the thumbnail for a video file, they can select a control icon which plays the video file as a motion sequence on the computer monitor.
Because the motion video sequence is normally more highly compressed than the still image thumbnail, the first frame of the video sequence in the navigation display can have a poorer image quality than the still image thumbnail. This makes the display less attractive. If the target data rate used to produce the compressed motion video file is made higher, the quality of the first frame, and all other frames, will be increased. However, the size of the compressed video file will also be greatly increased, thus reducing the number of images that can be stored in the digital memory.