  We introduce a imaging modality that works by transiently masking
image-subregions during a single exposure of a CCD frame. By offsetting
subregion exposure time, temporal information is embedded within each stored
frame, allowing simultaneous acquisition of a full high spatial resolution
image and a high-speed image sequence without increasing bandwidth. The
technique is demonstrated by imaging calcium transients in heart cells at 250
Hz with a 10 Hz megapixel camera.
