If you want to capture a single frame as a still image, you can use the WM_CAP_GRAB_FRAME_NOSTOP or WM_CAP_GRAB_FRAME message (or the capGrabFrameNoStop or capGrabFrame macro) to capture the digitized image in an internal frame buffer. You can freeze the display on the captured image by using WM_CAP_GRAB_FRAME. Otherwise, use WM_CAP_GRAB_FRAME_NOSTOP.
Once captured, you can copy the image for use by other applications. You can copy an image from the frame buffer to the clipboard by using the WM_CAP_EDIT_COPY message (or the capEditCopy macro). You can also copy the image from the frame buffer to a device-independent bitmap (DIB) by using the WM_CAP_FILE_SAVEDIB message (or the capFileSaveDIB macro).
Your application can also use the two single-frame capture messages to edit a sequence frame by frame, or to create a time-lapse photography sequence.