在RGB图像上应用Matlab图像滤镜

HussainBiedouh 发表于 Dev

侯赛因·比杜

我有下面的Matlab代码来处理两个图像，灰度图像和RGB图像。关键是要在两个图像上应用Average，Gaussian和Laplacian过滤器。

%%Clear
clear
clc
%%Reading images
gray=imread('cameraman.tif')
[gray_table gray_map]=gray2ind(gray,256)
rgb=imread('peppers.png')
[rgb_table rgb_map]=rgb2ind(rgb,256)
%%Creating filters
average=fspecial('average',3)
gaussian=fspecial('gaussian',3,0.5)
laplacian=fspecial('laplacian',0.9)
%%Applying filters
average_filterd_gray_table=imfilter(gray_table,average)
gaussian_filterd_gray_table=imfilter(gray_table,gaussian)
laplacian_filterd_gray_table=imfilter(gray_table,laplacian)
average_filterd_rgb_table=imfilter(rgb_table,average)
gaussian_filterd_rgb_table=imfilter(rgb_table,gaussian)
laplacian_filterd_rgb_table=imfilter(rgb_table,laplacian)
%%view
figure
subplot(1,4,1),imshow(gray_table,gray_map),title('Original Indexed Gray')
subplot(1,4,2),imshow(average_filterd_gray_table,gray_map),title('Average Filtered Indexed Gray')
subplot(1,4,3),imshow(gaussian_filterd_gray_table,gray_map),title('Gaussian Filtered Indexed Gray')
subplot(1,4,4),imshow(laplacian_filterd_gray_table,gray_map),title('Laplacian Filtered Indexed Gray')
figure
subplot(1,4,1),imshow(rgb_table,rgb_map),title('Original Indexed RGB')
subplot(1,4,2),imshow(average_filterd_rgb_table,rgb_map),title('Average Filtered Indexed RGB')
subplot(1,4,3),imshow(gaussian_filterd_rgb_table,rgb_map),title('Gaussian Filtered Indexed RGB')
subplot(1,4,4),imshow(laplacian_filterd_rgb_table,rgb_map),title('Laplacian Filtered Indexed RGB')

该代码适用于灰度图像。但是在RGB图像上，它只会给出失真的结果。如何解决？

Benoit_11

根据文档rgb2ind（单击此处）：

像这样加载RGB图像时：

[X,map] = rgb2ind(RGB,n)，该文档说：

注意生成的图像X中的值是颜色图映射的索引，不应在数学处理（例如过滤操作）中使用。

因此，最好直接过滤RGB图像。以下工作正常：

clear
clc
close all

RGBImage = imread('peppers.png');

average = fspecial('average',3);
gaussian=fspecial('gaussian',3,0.5);
laplacian=fspecial('laplacian',0.9);

RGB_Average = imfilter(RGBImage,average);
RGB_Gaussian= imfilter(RGBImage,gaussian);
RGB_Laplacian = imfilter(RGBImage,laplacian);

figure;
subplot(2,2,1)
imshow(RGBImage)
title('Original')

subplot(2,2,2)
imshow(RGB_Average)
title('Average')

subplot(2,2,3)
imshow(RGB_Gaussian)
title('Gaussian')

subplot(2,2,4)
imshow(RGB_Laplacian)
title('Laplacian')