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There's a few issues with that line of code: <ul> <li>If your image is RGB (e.g., loaded from colour Jpeg or something), you'll have to add 3 layers of noise; e.g., use <pre><code>rand([size(originalimage) 3]) </code></pre></li> <li><code>255*rand()</code> generates double-valued numbers, whereas your image will probably be of type <code>uint8</code> or so (check with <code>class(originalimage)</code>). To fix, use <code>randi</code> for instance: <pre><code>noisyimage = randi(255, [size(originalimage) 3], class(originalimage)); </code></pre></li> <li>you add noise of maximum magnitude 255 to all pixels. This might overflow many of your pixels (that is, get assigned values higher than 255). To avoid, use something like <pre><code>noisyimage = min(255, originalimage + randi(...) ); </code></pre></li> <li>The noise direction is only positive. True noise also sometimes brings down the values of the pixels. So, use something like <pre><code>noisyimage = max(0, min(255, originalimage + randi(...)-127 ); </code></pre></li> <li>the maximum amplitude of 255 is actually way too big; you'll likely destroy your whole image and only get noise. Try a few different amplitudes, <code>A</code>, like so: <pre><code>noisyimage = max(0, min(255, originalimage + randi(A, ...)-round(A/2) ); </code></pre></li> <li>The uniform distribution which <code>randi</code> uses is not a really good source of noise; you'd want some other distribution. Use the normal distribution: <pre><code>uint8(A*randn(...)-round(A/2)) </code></pre> or gamma: <pre><code>uint8(A*randg(...)-round(A/2)) </code></pre> etc.</li> </ul> Now, that should get you started :) 
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1. POHow to add impulsive and gamma noise to an image without using imnoise function in matlab?
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1. USRody Oldenhuis
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1. POHow to add impulsive and gamma noise to an image without using imnoise function in matlab?
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1. CODear friend, Thanks for your help, But i still cannot figure it out how to add Gamma noise to a RGB image
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