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Enabling High Grayscale Resolution Displays and Accurate Response Time Measurements on Conventional Computers
Published on: February 29, 2012
Perceptual coding of images for halftone display
1Dept. of Electr. Eng. and Comput. Sci., Michigan Univ., Ann Arbor, MI.
Summary
This study introduces a novel gray-scale image coding method for laser printers, achieving higher compression rates by delaying halftoning until the receiver. This allows for printer-specific optimization and improved image quality.
Area of Science:
- Image processing
- Computer vision
- Digital printing
Background:
- Conventional gray-scale image transmission for facsimile and printing involves halftoning before transmission, often using entropy coding like CCITT Group 3 or JBIG.
- This pre-transmission halftoning limits receiver-side adaptability to specific printer characteristics and halftoning algorithms.
Purpose of the Study:
- To develop a new technique for coding gray-scale images for facsimile transmission and laser printing.
- To enable receiver-side halftoning for printer-specific optimization.
- To achieve higher compression rates compared to conventional methods.
Main Methods:
- A perceptually based subband coding approach is employed for gray-scale image encoding.
- A perceptual masking model, empirically derived for printed images using a 300 dots/inch write-black laser printer and a standard halftoning scheme, is utilized.
- The image is converted to a binary pattern and printed only at the receiver.
Main Results:
- The proposed technique achieves higher compression rates than conventional methods.
- It allows the receiver to tune the halftoning process to the specific printer.
- For nearly transparent coding of gray-scale images, the technique requires lower data rates than standard facsimile techniques.
Conclusions:
- The new coding technique offers significant advantages for gray-scale image transmission and laser printing.
- Receiver-side halftoning provides flexibility and potentially better print quality by adapting to printer specifics.
- The method demonstrates superior compression efficiency for high-quality image reproduction.
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