Text and image sharpening of scanned images in the JPEG domain

Author

Bhasharan, V. ; Konstantinides, Konstantinos ; Beretta, Giordano

Author_Institution

Hewlett-Packard Co., Palo Alto, CA, USA

Volume

2

fYear

1997

fDate

26-29 Oct 1997

Firstpage

326

Abstract

The visual quality of scanned color documents suffers because of inherent limitations in color scanners. In cases where the scanned documents will also be compressed using the JPEG standard, we present a new technique that sharpens the compressed images in the DCT domain. Sharpening is achieved by suitably scaling each element of the encoding quantization table to enhance the high-frequency characteristics of the image. Experimental results show improved text and image quality with no additional computation cost

Keywords

code standards; data compression; discrete cosine transforms; document image processing; image coding; image colour analysis; image enhancement; image scanners; quantisation (signal); telecommunication standards; transform coding; DCT domain; JPEG domain; JPEG standard; color scanners; compressed images; document compression; encoding quantization table; experimental results; high-frequency characteristics; image enhancement; image quality; image sharpening; scanned color documents; scanned images; text sharpening; visual quality; Computational efficiency; Discrete cosine transforms; Encoding; Frequency domain analysis; Image coding; Image quality; Kernel; Laboratories; Quantization; Tin; Transform coding;

fLanguage

English

Publisher

ieee

Conference_Titel

Image Processing, 1997. Proceedings., International Conference on

Conference_Location

Santa Barbara, CA

Print_ISBN

0-8186-8183-7

Type

conf

DOI

10.1109/ICIP.1997.638759

Filename

638759