TY - JOUR
T1 - Adaptive classification and subsampling for block transform image coding
AU - Chang, Ih Hua
AU - Chang, Pao Chi
PY - 1997/5
Y1 - 1997/5
N2 - We present a block transform image coding system which preprocesses the image by adaptive subsampling based on the local activity levels. An input image is segmented into high/low activity blocks by combined L1 norm and mean difference classification methods. Low activity blocks are subsampled and encoded by conventional transform coding, such as JPEG, MPEG, and H.261, while high activity blocks are directly encoded by the transform coding. As a result, it yields good quality in both smooth and complex areas of the image at low bitrates.
AB - We present a block transform image coding system which preprocesses the image by adaptive subsampling based on the local activity levels. An input image is segmented into high/low activity blocks by combined L1 norm and mean difference classification methods. Low activity blocks are subsampled and encoded by conventional transform coding, such as JPEG, MPEG, and H.261, while high activity blocks are directly encoded by the transform coding. As a result, it yields good quality in both smooth and complex areas of the image at low bitrates.
UR - http://www.scopus.com/inward/record.url?scp=0031145812&partnerID=8YFLogxK
M3 - 期刊論文
AN - SCOPUS:0031145812
VL - 4
SP - 165
EP - 172
JO - Journal of the Chinese Institute of Electrical Engineering, Transactions of the Chinese Institute of Engineers, Series E/Chung KuoTien Chi Kung Chieng Hsueh K'an
JF - Journal of the Chinese Institute of Electrical Engineering, Transactions of the Chinese Institute of Engineers, Series E/Chung KuoTien Chi Kung Chieng Hsueh K'an
SN - 1023-4462
IS - 2
ER -