Aiming at a robust and adaptive dla approach , the authors first manage to find a set of representative filters and statistics to characterize typical texture patterns in document images , which is through a visual similarity testing process 虽然在之后的研究中也引入了聚类算法决定现场参数，但更多是用于分析二值图像上的几何特征，在图象质量较差时不适用。
First , the initial threshold is obtained from the balanced - processing image . second , the binarization of the balanced - processing image is done by increasing the threshold gradually , and the black blocks appearing in the binary image are marked one by one 首先对基于均衡处理后的图像估计出初始阈值;其次采用阈值递增法逐次二值化图像,并对二值图像中的黑块逐一标记。
In this algorithm , the intuitionistic property is assured by using the binary image as the watermark ; discrete cosine transform and classical edge detection algorithm are adopted to determine the imbedded zones for the watermark 在此算法中，以二值图像作为水印，具有较强的直观性；利用经典的数字图像处理技术中的离散余弦变换和边缘检测算法确定水印嵌入区域并完成水印嵌入。
This algorithmcarries on two values pictures processing in the differencefoundation , according to the human body statistical characteristic , proposed through the judgement projection curve second time derivativesize , determines the person face boundary the method 该算法在差分的基础上进行二值图像处理，根据人体的统计特征，提出通过判断投影曲线的二阶导数大小，来确定人脸边界的方法。
Finally , the automatic opto - electronical hybrid joint transform correlator was set up , which produced a quite good recognition result for both binarized image and complicated grayscale - level images . this paper also discussed the effects of lctv on jps 分析了液晶电视对联合功率谱的影响，提出了低通滤波和适量离焦的解决方案，分别对二值图像和复杂的灰度图像进行实验，得到了很好的识别结果。
Firstly , we showed the basic functions of dilation and erosion in mathematical morphology . afterwards , we extracted the edge in binary images by using these functions . the experiments testified that these two functions could extract the edge in binary images effectively 首先研究了将数学形态学的膨胀和腐蚀运算用于二值图像的边缘提取，由实验结果表明两种基本运算都可以较好地提取出二值图像的边缘。
3 . after analyses the distortion of pixel values and geometry during the ps process , we achieve the rst ( rotation , scale , translation ) invariants using characteristics of fourier transformation , and extract secret information successfully 针对ps ( print - scan )过程引起的图像像素失真及几何失真，我们利用傅立叶变换的特性，得到rst ( rotation ， scale , translation )不变量，解决了纸质二值图像中的信息隐藏问题。
In this paper the visually recognizable binary image is selected as watermark information , which is embedded in the transform domain through transforming the original audio signal ( discrete cosine transform and discrete wavelet transform ) 本文选用二值图像作为水印信息，通过对原始音频信号做变换，在变换域内嵌入水印，采用的是离散余弦变换( discretecosinetransform ? dct )和离散小波变换( discretewavelettransform ? dwt ) 。
Median filtering is chosen to modify the fuzzy edge by using the smoothing arithmetic , sobel operator is used to detect edge because of its filtering characteristic . image is changed from gray - scale to two - valued according to the threshold which is automaticly selected by otsu 选用中值滤波减小平滑算法导致的边缘模糊;利用有滤波特性的sobel算子进行边缘检测;使用最大类间方差自动确定阈值,将灰度图像转化为二值图像。
The other one is a morphological corner extraction algorithm based on the “ hit - number ” , which is suitable to both the binary and the gray - scale images . the algorithm has high detection accuracy , strong noise restraining ability , and is simple in calculation and easy to be realized on hardware 二是基于“击中数”的角点提取算法,可以在二值图像和灰度图像中提取角点,具有检测准确度高、抗噪性能好、计算量小和硬件实现方便等优点。
