Main Content


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.


collapse all

Read a sample image of data type uint8.

Im = imread('peppers.png');

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

collapse all

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

Output Arguments

collapse all

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