数字图像处理与分析实验9 综合练习(一)_参考答案

实验9 综合练习(一)
实验目的：
1.对需要进行处理的图像分析，正确运用所学的知识，采用
正确的步骤，对图像进行各类处理，以得到令人满意的图
像效果。

实验内容：
1.将bone_scan.jpg图像文件读入Matlab，按照以下步骤对
其进行处理：
a)用带对角线的Laplacian对其处理，以增强边缘。

W1=[-1 -1 -1
-1 8 -1
-1 -1 -1]
b)用imadd函数叠加原始图像，可以看出边界增强了，但
噪声增强了，应想法降低。

c)对原图像进行Sobel滤波。

(用fspecial生成)
d)并用imfilter对(c)的结果进行5×5邻域平均，以减
少噪声。

e)用immultiply函数处理经（b）步骤和（d）步骤处理
后的图像，噪声得以减少。

f)最后用imadjust函数做幂次灰度变换，以增强dynamic
range。

（多试几次，参考：γ取0.5）
要求用imshow函数显示经每一步处理后的图像，比对效果。

参考程序与处理结果
========================================================= =============
%Enhancing a image of whole body bone scan by combining various spatial
% enhancement methods, the strategies is as following:
% ========================================================
% 1. Utilize the Laplacian to highlight fine detail
% 2. Utilize the gradient to enhance prominent edges
% 3. Combine Laplacian and gradient to get the detail-enhanced and noise-compressed image % 4. Increase the contrast of low gray levels by using a gray-level transformation.
% ==========================================================
% The original image named 'Fig0306(a)(bone-scan).tif' is under the
% directory: J:\course teaching\ҽѧͼÏñ´¦Àí\ʵÑé\ʾÀýͼÏñ
% Copyright by Huang zhongchao, July 16, 2006
clear all;
close all;
f = imread('J:\course teaching\ҽѧͼÏñ´¦Àí\ʵÑé\ʾÀýͼÏñ\Fig0306(a)(bone-scan).tif');
f1 = im2double(f);
h1 = fspecial('sobel'); % or directly type h=[-1 -2 -1;0 0 0;1 2 1];
g1 = imfilter(f1,h1);
subplot(121);imshow(f);
title('the original image');
%b1 = mat2gray(g1);
subplot(122);imshow(g1);
title('the Sobel gradient');
h2 = fspecial('average',5) ; %procducing a averageing filter
g2 = imfilter(g1,h2);
figure(2);
subplot(121);imshow(g2);
title(' the smoothed gradient image');
h3 = [-1 -1 -1; -1 8 -1;-1 -1 -1]; % Laplacian mask
g3 =imfilter(f1,h3);
%b2 = mat2gray(g3);
subplot(122);imshow(g3);
title('the Laplacian image');
g4 = g3+f1;
figure(3);
subplot(121);imshow(g4)
title('sharped image by adding laplacian filtered and original image');
g5 = g4.* g2;
subplot(122);imshow(g5);
title('the product of smoothed gradient and Laplacian image');
g6 = g5+f1;
figure(4);
subplot(121);imshow(g6);
title('the sum of product and original image');
% constrast spreading by power-law transformation with r=0.5 and c=1;
gamma = 0.5;
c = 1;
g7 = c.*g6.^gamma;
figure(4);
subplot(122);imshow(g7);
title('the end result by combining the sharping and gradient operation');
========================================================= =============
运行结果参考：。