Document Color Optimization for Monochrome Fax Readability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fax technologies struggle to effectively transmit documents with colors or shades of gray, as they are often converted to 1-bit black and white, leading to indistinguishable elements and readability issues, particularly when text and background colors have similar brightness.
Innovation Solution
The method involves identifying color and shade elements in documents, replacing them with solid monochrome colors, dithered surfaces, or monochrome patterns, and outlining certain elements to enhance distinguishability before converting to a fax-compliant format.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If color elements are converted to 1-bit black and white for fax transmission, then compatibility with traditional fax devices is improved, but readability and distinguishability of elements deteriorate
Solution Approach 1:
The patent applies preliminary action by performing outlining on color elements before converting the document to 1-bit black and white format. The outlining process adds high-contrast borders to color elements in advance, ensuring they remain distinguishable after the subsequent monochrome conversion. This pre-processing step preserves element distinguishability while maintaining compatibility with traditional fax devices that only support 1-bit transmission.
2Loss of information
If dithering is used to represent color brightness, then color information is preserved, but element distinguishability deteriorates when text and background have similar brightness
Solution Approach 1:
The patent applies preliminary anti-action by counteracting the potential readability problems caused by dithering through the outlining process. Before dithering converts color elements to monochrome patterns, the outlining step adds high-contrast borders that ensure text and background elements remain distinguishable even when their dithered patterns have similar average brightness. This pre-countermeasure eliminates the reliability issue before it can manifest.
Solution Approach 2:
The patent combines multiple techniques into a composite solution: dithering for color information preservation is combined with outlining for distinguishability assurance. The dithered pattern provides color representation while the overlaid outline provides high-contrast boundaries, creating a composite visual structure that achieves both color fidelity and element distinguishability in the final 1-bit fax transmission.
3Reliability
If all color elements are outlined to enhance distinguishability, then readability is improved, but device complexity and processing time increase
Solution Approach 1:
The patent applies local quality by selectively outlining only certain color elements rather than all elements uniformly. The system identifies and applies outlining primarily to text elements and critical graphical elements that require high distinguishability, while potentially omitting outlines from less critical elements. This localized approach improves readability where needed while minimizing the additional processing complexity and file size increase.
Data Source
AI summary
Methods, apparatus, software, and systems of the present invention allow for optimization of color and shades of gray documents prior to their conversion to a monochrome format. If color/gray elements are identified in the document, the distance between them and their intensity is determined. If there are elements with the same or similar intensity in close proximity to each other, colors of some of the elements may be replaced with solid monochrome colors, and/or dithered surfaces, and/or monochrome patterns. Further, the elements may be outlined. These improvements make elements in the document more distinguishable after its conversion to a monochrome format. The described color optimization and outlining may have wide applicability in the Internet Fax technology.