Add note about GPL to code

README.txt

@@ -1,8 +1,21 @@
-This directory tree is for imgcomp version 0.8 (December 2015), by Matthias Wandel
+This directory tree is for imgcomp version 0.8 (January 2016), by Matthias Wandel
 Imgcomp uses parts of libjpeg, which are included in the source tree.
 
-To use imgcomp, you must compile it.  After unpacking it on a raspberry pi, type "make"
+To use imgcomp, you must compile it.  After unpacking it on a Raspberry Pi, type "make"
 
 For more information, please see the files in the "docs" directory.
 
 
+imgcomp is licensed under the GPL version 2 (not version 3)
+For detais, please see here: http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html
+
+This program is free software; you can redistribute it and/or
+modify it under the terms of the GNU General Public License
+as published by the Free Software Foundation; either version 2
+of the License.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+

src/blink_camera_led.c

@@ -1,9 +1,10 @@
-//
+//-----------------------------------------------------------------------------------
 //  This program based on "How to access GPIO registers from C-code on the Raspberry-Pi
 //  Example program
 //  Blinks camerae LED on raspberry Pi model B+
 //
 //  I have not been able to figure out how to make this work on the Pi2.
+//-----------------------------------------------------------------------------------
 
 #define BCM2708_PERI_BASE        0x20000000
 #define GPIO_BASE                (BCM2708_PERI_BASE + 0x200000) /* GPIO controller */

src/compare.c

@@ -1,3 +1,9 @@
+//-----------------------------------------------------------------------------------
+// imgcomp image comparison module
+// Matthias Wandel 2015
+//
+// Imgcomp is licensed under GPL v2 (see README.txt)
+//-----------------------------------------------------------------------------------
 #include <stdio.h>
 #include <stdio.h>
 #include <malloc.h>

src/dir_win.c

@@ -1,9 +1,14 @@
+//-----------------------------------------------------------------------------------
+// Implements unix style directory functions for windows.  This module used for
+// windows test development of imgcomp.  Not part of the linux build.
+//
+// Copied from:
+// http://www.opensource.apple.com/source/apache_mod_php/apache_mod_php-4.3/php/win32/readdir.c
+//-----------------------------------------------------------------------------------
 #include <malloc.h>
 #include <string.h>
 #include <errno.h>
 #include "readdir_win.h"
-// Copied from:
-// http://www.opensource.apple.com/source/apache_mod_php/apache_mod_php-4.3/php/win32/readdir.c
 
 /**********************************************************************
  * Implement dirent-style opendir/readdir/closedir on Window 95/NT

src/exif.c

@@ -1,7 +1,8 @@
 //--------------------------------------------------------------------------
 // Copied from jhead project to parse exif file header.
-//
 // Matthias Wandel
+//
+// Imgcomp is licensed under GPL v2 (see README.txt)
 //--------------------------------------------------------------------------
 #include "jhead.h"
 

src/imgcomp.h

@@ -1,5 +1,8 @@
 //----------------------------------------------------------------------------
-// image comparator tool prototypes
+// imgcomp structures and function prototypes
+// Matthias Wandel 2015
+//
+// Imgcomp is licensed under GPL v2 (see README.txt)
 //----------------------------------------------------------------------------
 
 typedef struct {

src/jhead.h

@@ -1,10 +1,7 @@
 //--------------------------------------------------------------------------
-// Include file for jhead program.
+// Include file for pieces of jhead project used in imgcomp.
 //
-// This include file only defines stuff that goes across modules.  
-// I like to keep the definitions for macros and structures as close to 
-// where they get used as possible, so include files only get stuff that 
-// gets used in more than one file.
+// Matthias Wandel 2015
 //--------------------------------------------------------------------------
 #include <stdio.h>
 #include <stdlib.h>

src/jpeg2mem.c

@@ -1,6 +1,8 @@
 //----------------------------------------------------------------------------------------
-// Code for using libjpeg to read an image into memory.
-// from:  stackoverflow.com/questions/5616216/need-help-in-reading-jpeg-file-using-libjpeg
+// Code for using libjpeg to read an image into memory for imgcomp
+// Based on code from:  stackoverflow.com/questions/5616216/need-help-in-reading-jpeg-file-using-libjpeg
+//
+// Imgcomp is licensed under GPL v2 (see README.txt)
 //----------------------------------------------------------------------------------------
 #include <stdio.h>
 #include <stdio.h>

src/jpgfile.c

@@ -1,7 +1,8 @@
 //--------------------------------------------------------------------------
 // Module to make exif.c from jhead project work.
+// Matthias Wandel 2015
 //
-// Matthias Wandel
+// Imgcomp is licensed under GPL v2 (see README.txt)
 //--------------------------------------------------------------------------
 #include "jhead.h"
 

src/main.c

@@ -1,6 +1,9 @@
 //-----------------------------------------------------------------------------------
 // Simple tool for monitor continuously captured images for changes
 // and saving changed images, as well as an image every N seconds for timelapses.
+// Matthias Wandel 2015
+//
+// Imgcomp is licensed under GPL v2 (see README.txt)
 //-----------------------------------------------------------------------------------
 #include <stdio.h>
 #include <ctype.h>		// to declare isupper(), tolower() 

src/readdir_win.h

@@ -1,3 +1,6 @@
+// Include file to go with readdir.c
+// Used only on windows build, which is only used for testing algorithms
+
 #ifndef READDIR_H
 #define READDIR_H
 

src/start_raspistill.c

@@ -1,5 +1,8 @@
 //----------------------------------------------------------------------------------------
 // Code to launch raspistill as a separately running process
+// Matthias Wandel 2015
+//
+// Imgcomp is licensed under GPL v2 (see README.txt)
 //----------------------------------------------------------------------------------------
 #include <sys/types.h>
 #include <signal.h>

src/util.c

@@ -1,5 +1,8 @@
 //-----------------------------------------------------------------------------------
-// Various utility functions.
+// imgcomp Various utility functions.
+// Matthias Wandel 2015
+//
+// Imgcomp is licensed under GPL v2 (see README.txt)
 //-----------------------------------------------------------------------------------
 #include <stdio.h>
 #include <ctype.h>		// to declare isupper(), tolower()