数字图像处理实验一课件

1、数字图像处理实验一图像灰度变换及直方图显示熟悉matlab的编程环境；复习MATLAB语言的基本用法；掌握MATLAB语言中图象数据与信息的读取存储方法；掌握matlab中图像灰度变换方法；掌握在MATLAB中绘制灰度直方图的方法； 实验目的实验中运用的函数 A=imread(FILENAME.FMT) imshow(A,low high) imwrite(A,FILENAME.FMT) G = intrans(F, neg) G = intrans(F, log, C, CLASS) G = intrans(F, gamma, GAM) G = intrans(F, stretch, M,

2、E)实验中运用的函数imhist(I)：displays a histogram for the image I above a grayscale colorbar. imhist(I, n)：displays a histogram where n specifies the number of bins used in the histogramimhist(X, map) ：displays a histogram for the indexed image X.counts,x = imhist(.)： returns the histogram counts in counts a

3、nd the bin locations in x so that stem(x,counts) shows the histogram. 实验中运用的函数imhist(f)Bar(horz, v, width) v:一个行向量，包含被绘制的点 horz：与v维数相同的向量，包含水平标度值的增量，若忽略horz， 则horz在0到length（v）之间等分若干 width：0到1之间的数值。width为1时条状最明显，0时为线。Stem(horz, v, color_linestyle_marker, fill) color_linestyle_marker：颜色，线类型，标记 fill：若使

4、用fill，标记点颜色与corlor一致Plot(horz, v, color, g, linestyle,none,marker,s)实验内容读出一副图像，利用灰度变换函数，基于switch语句分别实现图像灰度的反变换，对数变换，对比度拉伸变换，gamma变换操作，利用subplot在一个图像窗口的不同区域分别显示变换的结果。针对灰度变换后的图像，采用不同的方法绘制直方图，分析每种灰度变换后，直方图之间的区别。实验内容：操作提示function yourOutput = Yourfunctionname (yourInput)H1 行参数介绍%读入图像利用imadjust实现反变换，及对数变

5、换，再利用intrans实现gamma变换和对比度拉伸变换。这里要进行哪种变换，需要利用switch语句来控制；分别把每种变换结果利用subplot显示出来对每种变换的图像进行直方图计算，并利用不同的方法显示直方图实验内容：操作提示function g = intrans(f, varargin)% Verify the correct number of inputs.error(nargchk(2, 4, nargin) % Store the class of the input for use later.classin = class(f); % If the input is of

6、 class double, and it is outside the range0, 1, and the specified transformation is not log, convert the input to the range 0, 1.if strcmp(class(f), double) & max(f(:) 1 & . strcmp(varargin1, log) f = mat2gray(f);else % Convert to double, regardless of class(f). f = im2double(f);end实验内容：操作提示% Determ

7、ine the type of transformation specified.method = varargin1;% Perform the intensity transformation specified. switch methodcase neg g = imcomplement(f); case log if length(varargin) = 1 c = 1; elseif length(varargin) = 2 c = varargin2; elseif length(varargin) = 3 c = varargin2; classin = varargin3;

8、else error(Incorrect number of inputs for the log option.) end g = c*(log(1 + double(f);实验内容：操作提示case gamma if length(varargin) 2 error(Not enough inputs for the gamma option.) end gam = varargin2; g = imadjust(f, , , gam); case stretch if length(varargin) = 1 % Use defaults. m = mean2(f); E = 4.0; elseif length(varargin) = 3 m = varargin2; E = varargin3; else error(Incorrect number of inputs for the stretch option.) end g = 1./(1 + (m./(f +