High-speed scanner having image processing for improving the color reproduction and visual appearance thereof
View Patent ↗A scanner for digitizing a document includes a digitizer for digitizing the document into a first color space; a circuit for converting the digitized data into a second color space having a luminance channel and two chrominance channels; a multiplexer having text, approximate actual color of a uniform area and a predetermined color as input for selecting either the text, approximate actual color or the predetermined color as outputs; and multiplexer control input which determines which of the outputs will be selected as actual output based on a uniform area of the document.
1. A scanner for digitizing a document comprising:
(a) a digitizer for digitizing the document into a first color space;
(b) a color space converter for converting the digitized data into a second color space having a luminance channel and two chrominance channels;
(c) a multiplexer having text, approximate actual color of a uniform area and a predetermined color as input for selecting either the text, approximate actual color or the predetermined color as outputs; and
(d) multiplexer control input which determines which of the outputs will be selected as actual output based on a uniform area of the document; wherein the multiplexer control input includes a first logic input having a line and/or text extractor for determining whether a pixel is text or an uniform area, and a second logic input for determining whether the uniform area is to be the approximate actual color or the predetermined color.
2. The scanner as in claim 1 , wherein the predetermined color is white.
3. The scanner as in claim 1 , wherein the first logic input further includes a dilation circuit for enlarging the extracted line and/or text.
4. The scanner as in claim 2 , wherein the second logic input includes a threshold circuit for determining whether the uniform area is white or chromatic color.
5. A method for scanning and digitizing documents, the method comprising the steps of:
(a) digitizing the document into a first color space;
(b) converting the digitized data into a second color space having a luminance channel and two chrominance channels;
(c) providing text, approximate actual color of uniform area and a predetermined color as multiplexed input, and providing multiplexed output as either the text, approximate actual color or the predetermined color as outputs; and
(d) determining which of the outputs will be selected as actual output based on a uniform area of the document; wherein step (c) includes (e) determining by a line and/or text extractor whether a pixel is text or a uniform area, and (f) if the uniform area, determining whether the uniform area is to be the approximate actual color or the predetermined color.
6. The method as in claim 5 , wherein step (c) includes providing white as the predetermined color.
7. The method as in claim 5 , wherein step (e) includes further providing a dilation circuit for enlarging the extracted line and/or text.
8. The method as in claim 5 , wherein step (e) includes providing a threshold circuit for determining whether the uniform area is white or chromatic color.