where is gl/image.h

Hi all
I’m a very new beginner to this stuf.
I’m trying to use an alredy written code and in this code GLUT libraries are used for solaris. In the code (c and C++) #include <gl/image.h> is used but I cannot find this file anywhere in GLUT libraris!!!??? (((
I appriciate any information you can give.

thanks a lot