Apple Final Cut Express 4 - Manual (Page 793)

Chapter 51 Working with Freeze Frames and Still Images 793
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About Sequence Freeze Frames
Unlike a freeze frame of a clip, a sequence freeze frame will not update if you
subsequently change the sequence the freeze frame was created from. However, the
clip media referenced by the sequence freeze frame can still be updated and the freeze
frame clip can be reconnected.
Exporting Still Images
You can easily export a still image of the current frame displayed in the Viewer or
Canvas. You do not need to create a freeze frame clip to export a still image.
To export a frame displayed in the Viewer or Canvas as a still-image file:
1 Position the playhead on the frame you want to export, then choose File > Export >
Using QuickTime Conversion.
2 In the Save dialog that appears, enter a name and choose a location for the image file.
3 Choose Still Image from the Format pop-up menu, then click Save.
For more details, see Chapter 69, “ Exporting Still Images and Image Sequences ,” on
page 1049.
Deinterlacing Still Video Images to Improve Image Quality
Standard definition (SD) video is almost always interlaced, so still images created from
SD video are interlaced, too. A single frame of interlaced video consists of two fields
that were originally captured at different moments in time. If there is a lot of motion
in the video content of a frame (such as a ball quickly moving past the camera), the
two fields contain very different visual information. When the entire frame is
displayed, objects in motion have a comblike appearance because the objects appear
in two places at once.
During normal video playback, interlacing is usually not very noticeable because the
fields are scanned so quickly. However, on still images, interlacing artifacts cause
some still images to flicker or strobe on an interlaced display (such as an NTSC or PAL
monitor). To eliminate interlacing artifacts, you can apply a deinterlacing filter in
Final Cut Express before you export a still image. (A deinterlacing filter simply
removes half the lines and interpolates the missing lines by using the remaining
lines.) You can also export the image without applying the filter and then apply a
deinterlacing filter in a separate graphics application.
Important: Final Cut Express often displays the Viewer and Canvas deinterlaced to
make the image clearer while you are editing. To make sure you catch any potential
interlacing artifacts in still images, always watch your video on a monitor that matches
your final screening format. For example, if you plan to output your movie to an NTSC
video format, you should monitor your sequence on an external NTSC monitor.