Image Processing Toolbox activated?

When I type into command window, license('test', 'image_toolbox'), it returns 1.

My code reads and displays images by imread, imshow. But it when I use mat2gray in the next line, there's an error "'mat2gray' requires Image Processing Toolbox."

Answer 1

[Walter Roberson]

You have the Image Processing Toolbox licensed but you do not have it installed

[Image Analyst]

Either reinstall the complete MATLAB, or use the Add-ons/Get Add ons button on the Home tab of the tool ribbon to install just the Image Processing Toolbox.

[Lucy]

great, works now! Thank you both :)