Octave: 'rgb2gray' undefined error
octave
Solution
The problem is that you didn't load your packages. When you type `pkg list` you can find which ones are loaded by an asterisk in front of their names. Load a package with `pkg load image`.
Having to load a packages is that thing that most users find strange but if you compare with other languages, such as Python, Perl, or C++, would you expect them to `import`, `use`, or `#include` every libraries available in the system by default? See Octave's FAQ for more details.
Problem
Please advise what to do to make the `rgb2gray` work in Octave. I found this thread, but still I would like to use the `rgb2gray` functionality instead of manually calculating for each color channel. The code that I run: ``` I = imread('smile.jpg'); G = rgb2gray(I); ``` The error I get: ``` error: 'rgb2gray' is undefined near line 10 column6 ``` Additional: Octave version: 3.6.4 Image package is installed. Version: 2.0.0. The 'rgb2gray.m' is installed in C:\Octave\share\octave\packages\image-2.0.0 Thanks,