An extension of the reduced-difference pyramid (RDP) algorithm is derived and proposed for lossy image compression with upper-bounded maximum error (semilossy). Quantization has been introduced into the basic RDP in two different ways: approximations are made either before or after taking the differences among pairs of adjacent nodes. The resulting peak-error propagation along the pyramid is theoretically investigated, and quantization strategies are suggested. Tests on the standard gray-scale Lena image show significant and steady rate-distortion improvements over the original RDP. As few fixed-point operations are required per pixel, on-line compression/decompression is feasible on general-purpose computers.
Rounded reduced-difference pyramid for semi-lossy image coding / L. ALPARONE; CAPPERI P.; AIAZZI B.; BARONTI S.; BENELLI G.. - In: OPTICAL ENGINEERING. - ISSN 0091-3286. - STAMPA. - 34:(1995), pp. 3277-3283. [10.1117/12.212976]
Rounded reduced-difference pyramid for semi-lossy image coding
ALPARONE, LUCIANO;
1995
Abstract
An extension of the reduced-difference pyramid (RDP) algorithm is derived and proposed for lossy image compression with upper-bounded maximum error (semilossy). Quantization has been introduced into the basic RDP in two different ways: approximations are made either before or after taking the differences among pairs of adjacent nodes. The resulting peak-error propagation along the pyramid is theoretically investigated, and quantization strategies are suggested. Tests on the standard gray-scale Lena image show significant and steady rate-distortion improvements over the original RDP. As few fixed-point operations are required per pixel, on-line compression/decompression is feasible on general-purpose computers.
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
