title: An example use of CIGaussianGradient filter for Core Image
body: <p>I am looking for a code sample of this Core Image filter for iOS.  Those filters with the inputImage in the parameter, I can figure out how to implement.  But the ones without the inputImage parameter, I am not sure how it works.  </p>
  
  <p>Here is the extract from Apple's doc:</p>
  
  <p>CIGaussianGradient</p>
  
  <p>Generates a gradient that varies from one color to another using a Gaussian distribution.
  Parameters</p>
  
  <p>inputCenter</p>
  
  <pre><code>A CIVector class whose attribute type is CIAttributeTypePosition and whose display name is Center.
  
  Default value: [150 150] Identity: (null) 
  </code></pre>
  
  <p>inputColor0</p>
  
  <pre><code>A CIColor class whose display name is Color 1.
  </code></pre>
  
  <p>inputColor1</p>
  
  <pre><code>A CIColor class whose display name is Color 2.
  </code></pre>
  
  <p>inputRadius</p>
  
  <pre><code>An NSNumber class whose attribute type is CIAttributeTypeDistance and whose display name is Radius.
  
  Default value: 300.00 Minimum: 0.00 Maximum: 0.00 Slider minimum: 0.00 Slider maximum: 800.00 Identity: 300.00
  </code></pre>