Can be repeated multiple times. Good for viewing high resolution image on low resolution display. Further Exploration Try the Interactive JPEG examples and the JPEG examples . I-frame provide us with an accessing point. Intra Frame Coding Macroblocks are 16x16 pixel areas on Y plane of original image.
Previous image is called reference image .
Image to code is called target image . Actually, the difference is encoded. Some blocks in macroblock will match well, others match poorly. GQuant Overall, bitstream is designed so we can skip data whenever possible while still unambiguous. H.261 Codec 7.