公开(公告)号：US06441923B1

公开(公告)日：2002-08-27

申请号：US09340848

申请日：1999-06-28

申请人： Thyagarajan Balasubramanian ,  Reiner Eschbach ,  Paul G. Roetling

发明人： Thyagarajan Balasubramanian ,  Reiner Eschbach ,  Paul G. Roetling

IPC分类号： G06F1500

CPC分类号： H04N1/6033

摘要： A method for calibrating a printer includes printing a set of color samples with the printer, the set of samples or calibration target generated dynamically in response to selected printer variables, and reflecting at least a portion of the printer gamut. Each printed color sample in the set of samples is measured calorimetrically, to determine the printer's response thereto, so that a calibration table can be generated, taking into account printer variables selected by a user.

摘要翻译： 用于校准打印机的方法包括：打印机打印一组颜色样本，响应于所选择的打印机变量动态生成样本集或校准目标，并反映打印机色域的至少一部分。 按照量热法测量样品组中的每个印刷色样，以确定打印机对其的响应，从而考虑到用户选择的打印机变量，可以产生校准表。

公开(公告)号：US06342951B1

公开(公告)日：2002-01-29

申请号：US09213656

申请日：1998-12-16

申请人： Reiner Eschbach ,  Karen M. Braun ,  Thyagarajan Balasubramanian ,  William A. Fuss

发明人： Reiner Eschbach ,  Karen M. Braun ,  Thyagarajan Balasubramanian ,  William A. Fuss

IPC分类号： G06F1500

CPC分类号： G06F15/00 ,  H04N1/4072 ,  H04N1/6027 ,  H04N1/6058

摘要： A new and improved method for mapping out-of-gamut colors into an output gamut in a manner which results in an output image created by an image output terminal which is aesthetically pleasing and faithful to the original input image. A plurality of input pixel color values IPV comprising an input gamut IG are respectively mapped to a corresponding plurality of output pixel color values OPV so that the dynamic lightness range of the input gamut IG is compressed to that of the output gamut OG. This is accomplished by inverting at least one of the gray values defining the input pixel value IPV, applying a gamma function thereto, and then reversing the inversion step. The value of gamma &ggr; controls the amount of lightness compression and is selected based upon either the darkest actual or the darkest expected color in the input gamut IG as compared to the darkest color in the output gamut OG. If necessary, a subsequent gamut clipping operation is performed to map all resulting out-of-gamut output pixel values XOPV to values in the output gamut OG as a second processing step. Preferably, a centroid gamut clipping operation is used to map each out-of-gamut value XOPV to the surface SOG of the output gamut OG.

摘要翻译： 一种用于将输出色域映射成输出色域的新的和改进的方法，其导致由图像输出端子创建的输出图像，其在美学上令人愉快并且忠实于原始输入图像。 包括输入色域IG的多个输入像素颜色值IPV分别映射到对应的多个输出像素色值OPV，使得输入色域IG的动态亮度范围被压缩为输出色域OG的动态亮度范围。 这是通过反转定义输入像素值IPV的灰度值中的至少一个，向其施加伽马函数，然后反转反转步骤来实现的。 γ伽马的值控制亮度压缩量，并且基于输入色域IG中与输出色域OG中的最暗颜色相比较，输入色域IG中的最暗实际或最暗预期颜色被选择。 如果需要，执行随后的色域剪切操作，以将所有产生的色域外输出像素值XOPV映射到输出色域OG中的值作为第二处理步骤。 优选地，使用质心色域剪切操作将每个域外值XOPV映射到输出色域OG的表面SOG。

公开(公告)号：US06335800B1

公开(公告)日：2002-01-01

申请号：US09210194

申请日：1998-12-11

申请人： Thyagarajan Balasubramanian

发明人： Thyagarajan Balasubramanian

IPC分类号： G06F1500

CPC分类号： G06F15/00 ,  G06F17/175 ,  H04N1/6019

摘要： An electronic imaging system includes a receiver for receiving a digital representation of an input image, and a conversion processor for converting the input image to an output image, typically defined by distinct color spaces. The conversion processor is configured as a multidimensional look up table containing nodes at each of series of predefined input addresses. Each node is preloaded with an output color value corresponding to the input addresses. The look up table can accommodate a more efficient placement of nodes within N-dimensional space by a particular method of multidimensional interpolation. The method includes applying an interpolation algorithm in N−1-dimensional space, and then performing a 1-dimensional linear interpolation in the remaining dimension between the resulting values. Such a method allows for nodes to be allocated to rapidly changing areas within the color space represented by the LUT, while less dynamic areas can be suitably served by fewer nodes.

摘要翻译： 电子成像系统包括用于接收输入图像的数字表示的接收器和用于将输入图像转换成通常由不同颜色空间定义的输出图像的转换处理器。 转换处理器被配置为在每一系列预定义的输入地址处包含节点的多维查找表。 每个节点预加载与输入地址对应的输出颜色值。 查找表可以通过多维插值的特定方法来适应N维空间内节点的更有效的放置。 该方法包括在N-1维空间中应用插值算法，然后在所得到的值之间的剩余维度中执行一维线性插值。 这种方法允许将节点分配给由LUT表示的颜色空间内的快速变化的区域，而较少的动态区域可以由更少的节点适当地服务。

公开(公告)号：US06285462B1

公开(公告)日：2001-09-04

申请号：US09192106

申请日：1998-11-13

申请人： Thyagarajan Balasubramanian ,  Reiner Eschbach

发明人： Thyagarajan Balasubramanian ,  Reiner Eschbach

IPC分类号： H04N140

CPC分类号： H04N1/52

摘要： A processing system for preparing a plural separation document image for printing, including a process for mitigation or reduction of three color moiré. An approximation of moiré amplitude is calculated, and compared to a reference. Where three color moiré mitigation is desirable, black is removed and replaced with other separation colors.

摘要翻译： 一种用于制备用于打印的多个分离文档图像的处理系统，包括用于减轻或减少三色莫尔条纹的处理。 计算莫尔振幅的近似值，并与参考值进行比较。 在需要三色莫尔条纹减轻的地方，黑色被去除并用其他分离颜色代替。

公开(公告)号：US06239886B1

公开(公告)日：2001-05-29

申请号：US09004295

申请日：1998-01-08

申请人： R. Victor Klassen ,  Thyagarajan Balasubramanian

发明人： R. Victor Klassen ,  Thyagarajan Balasubramanian

IPC分类号： G03F308

CPC分类号： H04N1/608

摘要： The present invention is directed to a method and apparatus for improving the efficiency of color correcting subsampled luminance and chrominance based data. More specifically, the present invention is directed to a method of applying a full conversion between color spaces for one pixel in a selected pixel block. Chrominance values are assigned to the remaining pixels based upon their luminance values relative to the luminance value of the converted pixel. The invention may be used to convert between various types of color spaces, and may be used in the processing of both device dependent and device independent data.

摘要翻译： 本发明涉及一种用于提高色彩校正子采样亮度和基于色度的数据的效率的方法和装置。 更具体地，本发明涉及一种在所选像素块中的一个像素的颜色空间之间应用完全转换的方法。 基于其相对于转换像素的亮度值的亮度值，将色度值分配给剩余的像素。 本发明可以用于在各种颜色空间之间进行转换，并且可以用于处理器件相关的和器件无关的数据。

公开(公告)号：US5739927A

公开(公告)日：1998-04-14

申请号：US480972

申请日：1995-06-07

申请人： Thyagarajan Balasubramanian ,  Martin Sidney Maltz

发明人： Thyagarajan Balasubramanian ,  Martin Sidney Maltz

IPC分类号： B41J2/525 ,  G03G15/01 ,  H04N1/46 ,  H04N1/60

CPC分类号： H04N1/6033

摘要： A color imaging system has a color correction table (10) connected to a printer (12). A set of refinement colors x.sub.i are selected to determine the accuracy of the system. The number of refinement colors selected is small in relation to the number of locations in the color correction table (10), e.g., 1-50%. For each refinement color x, the printer (12) prints a color patch of corresponding color. A measuring device (14) measures each color patch and determines a corresponding colorimetric value x'. A refinement table (16) is generated which maps x' to x using an error difference between x' and x. An interpolator (22) interpolates the known error values across the refinement table based on a weighted sum of the known error values. The weighting is inversely proportional to a Euclidean distance of each interpolated error value from the known error values.

摘要翻译： 彩色成像系统具有连接到打印机（12）的颜色校正表（10）。 选择一组细化颜色xi以确定系统的准确性。 选择的细化颜色的数量相对于颜色校正表（10）中的位置的数量是小的，例如1-50％。 对于每个细化颜色x，打印机（12）打印相应颜色的色块。 测量装置（14）测量每个色标并确定相应的色度值x'。 生成细化表（16），其使用x'和x之间的误差将x'映射到x。 插值器（22）基于已知误差值的加权和内插跨越细化表的已知误差值。 加权与每个内插误差值的欧几里德距离与已知误差值成反比。

公开(公告)号：US5649072A

公开(公告)日：1997-07-15

申请号：US472080

申请日：1995-06-07

申请人： Thyagarajan Balasubramanian

发明人： Thyagarajan Balasubramanian

IPC分类号： G06F3/12 ,  B41J2/525 ,  G06K15/02 ,  G06T5/00 ,  G06T11/00 ,  H04N1/46 ,  H04N1/60 ,  G06K15/00 ,  G03F3/08

CPC分类号： G06T11/001 ,  G06K15/02 ,  H04N1/6033 ,  G06K2215/0094

摘要： A color correction table (10) is generated which converts colorimetric RGB locations into device RGB color space. The conversions are determined based on a printer response of a printer (12) by inputting a set of device RGB values to be printed. The printer (12) prints a corresponding set of RGB color patches. A measuring device (14) measures each color patch and determines a colorimetric RGB location for each color patch. A transformer (16) determines a transformation for each colorimetric RGB location and its corresponding device RGB value which are then stored in the RGB locations of the color correction table (10). The table (10) is then refined by inputting the originally measured colorimetric RGB locations to the table (10) and recovering table device RGB values. A comparator (18) compares the table device RGB values with the originally printed device RGB values and determines a residual error for each colorimetric RGB location. An interpolator (18) interpolates the found residual errors to the other RGB locations of the color correction table based on a weighted sum of the found residual errors and a Euclidean distance between the RGB locations. A refining means (22) refines each of the table device RGB values with the interpolated residual errors. The refinement steps are then repeated until the residual errors are within a selected tolerance.

摘要翻译： 产生颜色校正表（10），其将比色RGB位置转换成设备RGB颜色空间。 通过输入要打印的一组设备RGB值，基于打印机（12）的打印机响应来确定转换。 打印机（12）打印相应的一组RGB色块。 测量装置（14）测量每个色标并确定每个色标的比色RGB位置。 变压器（16）确定每个色度RGB位置的变换及其对应的设备RGB值，然后存储在颜色校正表（10）的RGB位置。 然后通过将原始测量的比色RGB位置输入到表（10）并恢复表格设备RGB值来精化表（10）。 比较器（18）将表格设备RGB值与原始打印的设备RGB值进行比较，并确定每个色度RGB位置的残差。 内插器（18）基于所找到的残差误差和RGB位置之间的欧几里德距离的加权和，将找到的残差误差内插到颜色校正表的其它RGB位置。 精炼装置（22）利用内插的残差来精化每个表装置RGB值。 然后重复细化步骤，直到残留误差在选定的公差内。