Graphics

Image CDataMapping

The CDataMapping property controls whether an image is indexed or intensity. An indexed image is displayed by setting the CDataMapping property to 'direct', in which case the values of the CData array are used directly as indices into the figure's colormap. When the image command is used with a single input argument, it sets the value of CDataMapping to 'direct'.

• h = image(X); colormap(map)
  get(h,'CDataMapping')
  ans =
  
  direct
  

Intensity images are displayed by setting the CDataMapping property to 'scaled'. In this case the CData values are linearly scaled to form colormap indices. The scale factors are controlled by the axes CLim property. The imagesc function creates an image object whose CDataMapping property is set to 'scaled', and it also adjusts the CLim property of the parent axes. For example,

• h = imagesc(I,[0 1]); colormap(map)
  get(h,'CDataMapping')
  ans =
  
  scaled
  
  get(gca,'CLim')
  ans =
  
  [0 1]
  

Image CData

XData and YData

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