Share Email Print
cover

Proceedings Paper

Quality issues for archival of ancient documents
Author(s): Bruno Aiazzi; Stefano Baronti; Andrea Casini; Franco Lotti; Alberto Mattei; Leonardo Santurri
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

This paper reports about a study concerning the application of error bounded encoding to lossy image compression of ancient documents handwritten on parchments. Images are acquired in the RGB color space and previously transformed in the YUV color coordinate system before coding. The coding algorithm, named RLP, considered here is based on a classified DPCM enhanced by a fuzzy clustering initialization and followed by context based statistical modeling and arithmetic coding of prediction residuals that are quantized with user defined odd step sizes to allow rate control with a minimum peak error over the whole image, so as to exactly limit local distortions. Each YUV component is coded separately; after decoding images are transformed back to RGB color space and compared with the originals in order to quantify distortions. A relationship bounding the peak errors in the RGB color space one the peak error is fixed in the YUV color space is derived. An algorithm originally designed for estimating signal-dependent noise parameters and used to obtain useful information about the images of the documents is also reported in the paper. The performances of the coding method are superior with respect to conventional DPCM schemes thanks to its flexibility and robustness to changes in type of images. For the compression ratios requested by this application the gain of RLP over JPEG is consistent: nearly 2 dB and 5 dB in PSNR for compression ratios of 10 and 5 respectively.

Paper Details

Date Published: 17 November 2000
PDF: 12 pages
Proc. SPIE 4122, Mathematics and Applications of Data/Image Coding, Compression, and Encryption III, (17 November 2000); doi: 10.1117/12.409241
Show Author Affiliations
Bruno Aiazzi, Institute for Research on Electromagnetic Waves (Italy)
Stefano Baronti, Institute for Research on Electromagnetic Waves (Italy)
Andrea Casini, Institute for Research on Electromagnetic Waves (Italy)
Franco Lotti, Institute for Research on Electromagnetic Waves (Italy)
Alberto Mattei, Institute for Research on Electromagnetic Waves (Italy)
Leonardo Santurri, Institute for Research on Electromagnetic Waves (Italy)


Published in SPIE Proceedings Vol. 4122:
Mathematics and Applications of Data/Image Coding, Compression, and Encryption III
Mark S. Schmalz, Editor(s)

© SPIE. Terms of Use
Back to Top