《数字图像处理(MATLAB版)》的原文摘录

  • 去噪 亮度变换: varargin 变长输入 (f, varargin) 用nargchk检测变量输入 error(nargchk(2, 4, nargin)) nargin和nargout 判断图像的数组是什么格式的 用mat2gray转化成range [0, 1] if strcmp(class(f), 'double') & max(f(:)) > 1 & ... ~strcmp(varargin{1}, 'log') f = mat2gray(f); 不然转成double的方便操作 f = im2double(f); 反转图像 g = imcomplement(f) 使用对数变换减小动态范围 g = c*(log(1 + double(f))) Gamma变换 g = imadjust(f, [ ], [ ], gam) <图片3> 对比度拉伸方法增强 g = 1./(1 + (m./(f + eps)).^E) <图片2> 默认m = mean2(f); E = 4.0; changes the storage class of an image: g = changeclass(classin, g); 做映射还是用imadjust:g = imadjust(f, [low_in high_in], [low high]) 直方图处理: 归一化直方图 p = imhist(f, b)/numel(f) b是灰度级个数 绘制直方图imhist bar stem plot Enhance contrast using histogram equalization g = histeq(f, nlev) (自适应的变换函数) 直方图匹配(规定化) 也是使用histeq 不过是histeq = (f, hspec) 其中h... (查看原文)
    [已注销] 2赞 2013-02-17 15:11:02
    —— 引自章节:三四章节
  • The field of digital image processing refers to processing digital images by means of a digital computer (查看原文)
    百万de心Logos 2016-05-30 18:18:41
    —— 引自第31页
  • As a consequence, f(x,y) must be nonzero and finite; that is 0< f(x,y) < infinite (查看原文)
    百万de心Logos 2016-06-02 17:38:28
    —— 引自第51页
  • Incoming energy is transformed into a voltage by the combination of input electrical power and sensor material that is responsive to the particular type or energy being detected. (查看原文)
    百万de心Logos 2016-06-05 16:16:47
    —— 引自第103页
  • The quality of a digital image is determined to a large degree by the number of samples and discrete intensity levels used in sampling and quantization. (查看原文)
    百万de心Logos 2016-06-05 16:16:47
    —— 引自第103页
  • The section of the real plane spanned by the coordinates of an image is called the spatial domain, with x and y being referred to as spatial variables or spatial coordinates. (查看原文)
    百万de心Logos 2016-06-05 16:16:47
    —— 引自第103页
  • f(x, y) is a digital image if (x, y) are integers from z2 and f is a function that assigns an intensity value to each distinct pair of coordinates(x, y). (查看原文)
    百万de心Logos 2016-06-05 16:16:47
    —— 引自第103页
  • This digitization process requires that decisions be made regarding the values for M, N, and for the number, L, of discrete intensity levels. (查看原文)
    百万de心Logos 2016-06-05 16:16:47
    —— 引自第103页
  • due to storage and quantizing hardware considerations, the number of intensity levels typically is an integer power of 2.. (查看原文)
    百万de心Logos 2016-06-05 16:16:47
    —— 引自第103页
  • an image can be smoothed by attenuating the high-frequency components of its Fourier transform. Because edges and other abrupt changes in intensities are associated with high-frequency components, image sharpening can be achieved in the frequency domain by highpass filtering, which attenuates low-frequencies components without disturbing highfrequencies in the Fourier transform. (查看原文)
    侃大海 2021-01-02 09:20:57
    —— 引自第398页