Title :
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
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;
Conference_Titel :
Image Processing, 1997. Proceedings., International Conference on
Conference_Location :
Santa Barbara, CA
Print_ISBN :
0-8186-8183-7
DOI :
10.1109/ICIP.1997.638759
