基于MATLAB的rgb图像去噪

Question

我正在尝试从已经有噪声的RGB图像中去除噪声。我已经看过一些例子，其中盐和胡椒噪声被添加到干净的图像中，然后作为示例再次删除，但我正在读取一个已经有噪声的图像，如果这有意义的话。由于某些原因，这段代码没有对原始图像进行任何更改。根本没有消除任何噪音。任何帮助都将不胜感激。

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p = imread("train.jpg");

redChannel = p(:, :, 1);
greenChannel = p(:, :, 2);
blueChannel = p(:, :, 3);

% Median Filter the channels:
redMF = medfilt2(redChannel, [3 3]);
greenMF = medfilt2(greenChannel, [3 3]);
blueMF = medfilt2(blueChannel, [3 3]);

% Find the noise in the red.
noiseImage = (redChannel == 0 | redChannel == 255);
% Get rid of the noise in the red by replacing with median.
noiseFreeRed = redChannel;
noiseFreeRed(noiseImage) = redMF(noiseImage);
% Find the noise in the green.
noiseImage = (greenChannel == 0 | greenChannel == 255);
% Get rid of the noise in the green by replacing with median.
noiseFreeGreen = greenChannel;
noiseFreeGreen(noiseImage) = greenMF(noiseImage);
% Find the noise in the blue.
noiseImage = (blueChannel == 0 | blueChannel == 255);
% Get rid of the noise in the blue by replacing with median.
noiseFreeBlue = blueChannel;
noiseFreeBlue(noiseImage) = blueMF(noiseImage);
% Reconstruct the noise free RGB image
rgbFixed = cat(3, noiseFreeRed, noiseFreeGreen, noiseFreeBlue);

figure, imshow(rgbFixed);

Answer 1

作为Ander Biguri commented，有许多方法可以降低图像中的噪声。在这里枚举它们都超出了堆栈溢出的范围。但我会建议一种方法:中值滤波。我建议这样做是因为你已经在这么做了！

您正在将medfilt2应用于输入图像的每个通道。只需跳过后面的所有内容，只保留最后一行:将通道连接回RGB图像。

p = imread("train.jpg");

redChannel = p(:, :, 1);
greenChannel = p(:, :, 2);
blueChannel = p(:, :, 3);

% Median Filter the channels:
redMF = medfilt2(redChannel, [3 3]);
greenMF = medfilt2(greenChannel, [3 3]);
blueMF = medfilt2(blueChannel, [3 3]);

rgbFixed = cat(3, redMF, greenMF, blueMF)

figure, imshow(rgbFixed);

由于您的图像噪声非常大，您可能需要增加滤镜的大小。但你会在噪声和模糊之间做出妥协。