公开(公告)号：US06331902B1

公开(公告)日：2001-12-18

申请号：US09418956

申请日：1999-10-14

Applicant: Bob Chih-Ming Lin

Inventor： Bob Chih-Ming Lin

IPC: B41B100

CPC classification number: G06T3/4015 ,  G06F3/14 ,  G09G5/02 ,  G09G2340/0414 ,  G09G2340/0421 ,  G09G2340/0428 ,  H04N1/3935 ,  H04N1/4092 ,  H04N1/6025

Abstract: A pipeline processor for scaling and converting RGB color input images to CMYK at a magnification specifiable in 1 percent increments up to 400% includes a scaler having predefined main scale factors including one at maximum scale. An interim scale factor is selected from the main scale factors as one nearest the specified magnification toward the high end of the range. A pixel transformation is made at the interim scale factor between a subset of the source pixels and a corresponding subset of intermediate pixels using hardware circuits. The intermediate pixels are then interpolated to produce a scaled image by dropping an evenly spaced subset of the intermediate pixels when the magnification is less than the interim scale factor. A set of enhanced pixels is derived from the scaled image by proportionally weighting center pixels against average values of diagonally neighboring pixels. Color conversion is done by multiplex addressing of a lookup table using high-order portions of RGB values and incremented values to obtain sets of neighboring CMYK values. Conversion is completed by interpolating between the neighboring values using low-order portions of the RGB values. Halftone output data is obtained from comparisons of 8-bit pixel values with halftone pattern values from another lookup table that is addressed by pixel and line counters. Also disclosed is a method for scaling an image defined by an array of source pixels to produce an array of output pixels according to a received scale factor.

Abstract translation: 用于将RGB彩色输入图像缩放和转换为CMYK的流水线处理器以可以以1％增量指定的放大率高达400％包括具有预定义的主要比例因子的缩放器，包括最大比例的一个。 从主要比例因子中选择一个临时比例因子，作为距离该范围的高端的指定倍率最接近的比例因子。 使用硬件电路在源像素的子集和中间像素的相应子集之间的中间尺度因子处进行像素变换。 然后，当放大率小于临时比例因子时，通过丢弃中间像素的均匀间隔的子集，内插中间像素以产生缩放图像。 通过将中心像素与对角相邻像素的平均值成比例地加权，从缩放图像导出一组增强像素。 通过使用RGB值的高阶部分和递增值的查找表的多路寻址来获得颜色转换，以获得相邻CMYK值的集合。 通过使用RGB值的低阶部分在相邻值之间进行内插来完成转换。 从通过像素和行计数器寻址的另一查找表的半色调模式值的比较中获得半色调输出数据。 还公开了一种用于缩放由源像素阵列定义的图像以根据接收的比例因子产生输出像素的阵列的方法。