公开(公告)号：US08335015B2

公开(公告)日：2012-12-18

申请号：US12560709

申请日：2009-09-16

Applicant: R. Victor Klassen ,  Yongda Chen ,  Yonghui Zhao

Inventor： R. Victor Klassen ,  Yongda Chen ,  Yonghui Zhao

IPC: G06F15/00 ,  G06K1/00

CPC classification number: H04N1/6025 ,  H04N1/54

Abstract: Color separation systems and methods improve color constancy and smoothness of a color lookup table (LUT) for a printer. A plurality of nodes of the LUT may be defined in colorimetric space, and the nodes out of the printer gamut may be mapped to the printer gamut surface. A set of possible colorant combinations are then determined that produce each node in the LUT in a device independent color space using a non-linear minimization algorithm, such as, for example, a conjugate gradient algorithm. Next, a colorant combination may be determined for each and every node in the LUT based on an image quality metric. In some implementations, a smoothing filter may be used to smooth the lookup table.

Abstract translation: 颜色分离系统和方法可以改善打印机的颜色查找表（LUT）的颜色稳定性和平滑度。 可以在比色空间中定义LUT的多个节点，并且打印机色域之外的节点可以映射到打印机色域表面。 然后确定一组可能的着色剂组合，其使用非线性最小化算法（例如共轭梯度算法）在设备独立的颜色空间中产生LUT中的每个节点。 接下来，可以基于图像质量度量来确定LUT中的每个节点的着色剂组合。 在一些实现中，可以使用平滑滤波器来平滑查找表。

公开(公告)号：US20110286015A1

公开(公告)日：2011-11-24

申请号：US12782362

申请日：2010-05-18

Applicant: Martin S. Maltz ,  Raja Bala ,  Yonghui Zhao ,  Matthew Frederick Hoffmann

Inventor： Martin S. Maltz ,  Raja Bala ,  Yonghui Zhao ,  Matthew Frederick Hoffmann

IPC: H04N1/60 ,  G06K9/00

CPC classification number: H04N1/6019

Abstract: What is disclosed is a novel system and method for converting a set of L*a*b* values to CMYK color space in which all CMYK formulations that produce each L*a*b* value are found and enumerated. The CMYK formulations are found through a search algorithm starting with the lightest L*a*b* values then visiting neighboring L*a*b* values until the entire L*a*b* color set has been processed. The CMYK space is tessellated into a set of pentahedrons, and for each L*a*b* value, an enclosing pentahedron is found and the CMYK values corresponding to where the locus of this point penetrates each surface is recorded. Adjacent pentahedrons are then visited and this process continues until the gamut boundary is reached. The result is a piecewise linear representation of the CMYK locus containing all values that will give the target L*a*b* value. The present method provides a flexible and powerful approach for solving color management problems.

Abstract translation: 所公开的是用于将一组L * a * b *值转换为CMYK颜色空间的新型系统和方法，其中发现并列举了产生每个L * a * b *值的所有CMYK公式。 通过搜索算法找到CMYK公式，从最轻的L * a * b *值开始，然后访问相邻的L * a * b *值，直到整个L * a * b *颜色集合被处理。 CMYK空间被镶嵌成一组五面体，并且对于每个L * a * b *值，找到包围的五面体，并且记录与该点的轨迹穿过每个表面的位置相对应的CMYK值。 然后访问相邻的五面体，并且该过程继续，直到达到色域边界。 结果是包含将给出目标L * a * b *值的所有值的CMYK轨迹的分段线性表示。 本方法为解决颜色管理问题提供了灵活而强大的方法。

公开(公告)号：US20100040282A1

公开(公告)日：2010-02-18

申请号：US12191721

申请日：2008-08-14

Applicant: Raja Bala ,  Reiner Eschbach ,  Yonghui Zhao

Inventor： Raja Bala ,  Reiner Eschbach ,  Yonghui Zhao

IPC: G06K9/00

CPC classification number: G06K9/38 ,  G06K2009/0059 ,  G06K2209/01 ,  G06T7/11 ,  G06T7/155 ,  G06T7/194 ,  G06T2207/10008 ,  G06T2207/20036 ,  G07D7/005

Abstract: A method and system for identifying a fluorescence mark in a printed document includes using an image acquisition device to derive an input digital image that represents a printed document including a background and a fluorescence mark adjacent the background. The input digital image includes multiple color channel digital images, with each color channel digital image comprising a plurality of pixels each defined by a gray value. For each pixel of at least one of the color channel digital images, the gray value is adjusted based upon a variance of adjacent pixel gray values to define a filtered digital image including a plurality of pixels each defined by an adjusted gray value. Some pixels of the filtered digital image correspond to low variance regions of the input digital image and other pixels of the filtered digital image correspond to high variance regions of the input digital image. A binary image is derived that represents the filtered digital image by mapping each adjusted gray value of the filtered image to either a first or second possible binary pixel value. The binary image includes a binary representation of the fluorescence mark and a binary representation of the background. At least one morphological operation is performed on the binary image to adjust the pixel values of the binary representation of the background so that all pixel values of the binary representation of the background are opposite the binary pixel value used for the binary representation of the fluorescence mark. An ASCII character for the binary representation of the fluorescence mark (or each constituent character thereof) can be derived and compared to a known security code to authenticate the printed document.

Abstract translation: 用于识别印刷文档中的荧光标记的方法和系统包括使用图像获取装置来导出表示包括背景的印刷文档和邻近背景的荧光标记的输入数字图像。 输入数字图像包括多个彩色通道数字图像，每个彩色通道数字图像包括由灰度值定义的多个像素。 对于至少一个颜色通道数字图像的每个像素，基于相邻像素灰度值的方差来调整灰度值，以定义包括由调整的灰度值定义的多个像素的滤波数字图像。 滤波数字图像的一些像素对应于输入数字图像的低方差区域，并且滤波数字图像的其他像素对应于输入数字图像的高方差区域。 导出二进制图像，其通过将滤波图像的每个经调整的灰度值映射到第一或第二可能二进制像素值来表示经滤波的数字图像。 二进制图像包括荧光标记的二进制表示和背景的二进制表示。 对二进制图像执行至少一个形态学操作以调整背景的二进制表示的像素值，使得背景的二进制表示的所有像素值与用于荧光标记的二进制表示的二进制像素值相反 。 可以导出用于荧光标记（或其每个构成字符）的二进制表示的ASCII字符，并将其与已知的安全代码进行比较以验证打印文档。