TY - GEN
T1 - Improved scheme for object searching using moment invariants
AU - Lau, K. L.
AU - Siu, W. C.
AU - Law, Ngai Fong
PY - 2002/1/1
Y1 - 2002/1/1
N2 - For multimedia retrieval application, shape is always a conspicuous element of an object. Moment-based approaches are widely used for shape description due to its translation, scaling and rotation invariance. Moment invariants are defined in the continuous domain. However, when considering the digital images in practice, quantization errors are introduced. Thus, the moment invariants calculated might not be truly invariant. This paper presents an analysis of quantization effects on four moment-based approaches of both regular and irregular objects. From the analysis, the scaling errors for all approaches are large when the scaling factor is less than 0.5. Moreover, the rotational errors are big for the objects rotated other than the multiples of 90. Our experimental results show that Dudani moment invariants suffer the largest error for overall sensitivity, while Affine moment invariants show the smallest. Furthermore, this error analysis has also been applied successfully to object searching applications using a threshold selection scheme.
AB - For multimedia retrieval application, shape is always a conspicuous element of an object. Moment-based approaches are widely used for shape description due to its translation, scaling and rotation invariance. Moment invariants are defined in the continuous domain. However, when considering the digital images in practice, quantization errors are introduced. Thus, the moment invariants calculated might not be truly invariant. This paper presents an analysis of quantization effects on four moment-based approaches of both regular and irregular objects. From the analysis, the scaling errors for all approaches are large when the scaling factor is less than 0.5. Moreover, the rotational errors are big for the objects rotated other than the multiples of 90. Our experimental results show that Dudani moment invariants suffer the largest error for overall sensitivity, while Affine moment invariants show the smallest. Furthermore, this error analysis has also been applied successfully to object searching applications using a threshold selection scheme.
UR - http://www.scopus.com/inward/record.url?scp=84950000570&partnerID=8YFLogxK
M3 - Conference article published in proceeding or book
SN - 3540002626
SN - 9783540002628
T3 - Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
SP - 783
EP - 790
BT - Advances in Multimedia Information Processing - PCM 2002 - 3rd IEEE Pacific Rim Conference on Multimedia, Proceedings
PB - Springer Verlag
T2 - 3rd IEEE Pacific Rim Conference on Multimedia, PCM 2002
Y2 - 16 December 2002 through 18 December 2002
ER -