These labels are used to describe image size, which is related to resolution. In an NTSC video, standard full-screen resolution is 704×480 pixels. The Standard Image Format (SIF) is 352×240 and the QuarterSize Image Format (QSIF) is 276×120 pixels. The picture in an SIF file is bigger, but so is the data file! If you need to enlarge a QSIF to be full screen, the resolution (and picture detail) will be greatly decreased compared to an SIF of the same image.
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