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Default display range of image based on its class



range = getrangefromclass(I) returns the default display range of the image I based on its class type.


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Read a sample image of data type uint8.

Im = imread('peppers.png');

Figure contains an axes object. The axes object contains an object of type image.

Get the display range from the image. Images of type uint8 have pixel values in the range [0, 255].

rangeIm = getrangefromclass(Im)
rangeIm = 1×2

     0   255

Convert the image from type uint8 to type double.

RGB = im2double(Im);

Get the display range of the new image. The pixel values are in the range [0, 1], which is consistent with how the MATLAB® software interprets images of type double.

rangeRGB = getrangefromclass(RGB)
rangeRGB = 1×2

     0     1

Input Arguments

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Input image, specified as a numeric array or logical array.

Output Arguments

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Display range, returned as a 2-element numeric vector of the form [min max].

  • For single and double data, getrangefromclass returns the range [0 1] to be consistent with the way MATLAB® software interprets images of type double and single.

  • For integer data, getrangefromclass returns the minimum and maximum representable values for that integer class. For example, if the class is uint8, the dynamic range is [0 255].

  • For logical data, getrangefromclass returns the range [0 1].

Data Types: double

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

GPU Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Version History

Introduced before R2006a

See Also