公开(公告)号：US08351699B2

公开(公告)日：2013-01-08

申请号：US12642643

申请日：2009-12-18

申请人： Dalong Li ,  John Elton ,  Sebastian Steger

发明人： Dalong Li ,  John Elton ,  Sebastian Steger

IPC分类号： G06K9/00 ,  G06K9/38

CPC分类号： G06K9/38

摘要： A threshold determination method is selected from among a plurality of alternative global thresholding determination methods and, optionally, a local thresholding determination method based on characteristics of a histogram of grayscales values representing an image. When it is determined to use a global thresholding method, a single global binarization threshold value is determined using the selected global thresholding method. Various alternative global binarization threshold values include a predetermined constant, an average value of the two grayscale values, an Otsu method based threshold value, a Newton method based threshold value, and an Otsu method based threshold value based on a truncated version of the histogram. When it is determined to use local thresholding, a plurality of local binarization threshold values are determined corresponding to different non-overlapping blocks of the image. The determined binarization threshold(s) are applied to the gray scale pixel values to obtain a set of binary pixel values.

摘要翻译： 从多个备选全局阈值确定方法中选择阈值确定方法，并且可选地，基于表示图像的灰度值的直方图的特征来选择局部阈值确定方法。 当确定使用全局阈值方法时，使用所选择的全局阈值方法来确定单个全局二值化阈值。 各种替代的全局二值化阈值包括基于直方图的截断版本的预定常数，两个灰度值的平均值，基于Otsu方法的阈值，基于牛顿法的阈值和基于Otsu方法的阈值。 当确定使用本地阈值时，对应于图像的不同非重叠块来确定多个局部二值化阈值。 将确定的二值化阈值应用于灰度像素值以获得一组二进制像素值。

公开(公告)号：US20100158373A1

公开(公告)日：2010-06-24

申请号：US12642643

申请日：2009-12-18

申请人： Dalong Li ,  John Elton ,  Sebastian Steger

发明人： Dalong Li ,  John Elton ,  Sebastian Steger

IPC分类号： G06K9/00

CPC分类号： G06K9/38

摘要： A threshold determination method is selected from among a plurality of alternative global thresholding determination methods and, optionally, a local thresholding determination method based on characteristics of a histogram of grayscales values representing an image. When it is determined to use a global thresholding method, a single global binarization threshold value is determined using the selected global thresholding method. Various alternative global binarization threshold values include a predetermined constant, an average value of the two grayscale values, an Otsu method based threshold value, a Newton method based threshold value, and an Otsu method based threshold value based on a truncated version of the histogram. When it is determined to use local thresholding, a plurality of local binarization threshold values are determined corresponding to different non-overlapping blocks of the image. The determined binarization threshold(s) are applied to the gray scale pixel values to obtain a set of binary pixel values.

摘要翻译： 从多个备选全局阈值确定方法中选择阈值确定方法，并且可选地，基于表示图像的灰度值的直方图的特征来选择局部阈值确定方法。 当确定使用全局阈值方法时，使用所选择的全局阈值方法来确定单个全局二值化阈值。 各种替代的全局二值化阈值包括基于直方图的截断版本的预定常数，两个灰度值的平均值，基于Otsu方法的阈值，基于牛顿法的阈值和基于Otsu方法的阈值。 当确定使用本地阈值时，对应于图像的不同非重叠块来确定多个局部二值化阈值。 将确定的二值化阈值应用于灰度像素值以获得一组二进制像素值。