www.gusucode.com > images 案例代码 matlab源码程序 > images/ObtainLocalStructuralSimilarityIndexExample.m
%% Obtain Local Structural Similarity Index % This example shows how to measure the quality of regions of an image when % compared with a reference image. The |ssim| function calculates the % structural similarity index for each pixel in an image, based on its % relationship to other pixels in an 11-by-11 neighborhood. The function % returns this information in an image that is the same size as the image % whose quality is being measured. This local, pixel-by-pixel, quality % index can be viewed as an image, with proper scaling. %% % Read an image to use as the reference image. % Copyright 2015 The MathWorks, Inc. ref = imread('pout.tif'); %% % Create an image whose quality is to be measured, by making a copy of the % reference image and adding noise. To illustrate local similarity, isolate % the noise to half of the image. Display the reference image and the noisy % image side-by-side. A = ref; A(:,ceil(end/2):end) = imnoise(ref(:,ceil(end/2):end),'salt & pepper', 0.1); figure, imshowpair(A,ref,'montage') %% % Calculate the local Structural Similarity Index for the modified image % (A), when compared to the reference image (ref). Visualize the local % structural similarity index. Note how left side of the image, which is % identical to the reference image displays as white because all the local % structural similarity values are 1. [global_sim local_sim] = ssim(A,ref); figure, imshow(local_sim,[])