error: redeclaration of void iulib::addscaled

Hi, I'm trying to build iulib on ubuntu 16.06

rdi@rdi-adam:iulib (master)$ scons
scons: Reading SConscript files ...
compiling with high optimization
Checking for png_byte in C library png... (cached) yes
Checking for jpeg_std_error() in C library jpeg... (cached) yes
Checking for inflate in C library z... (cached) yes
Checking for TIFFOpen() in C library tiff... (cached) yes
Checking for C++ header file SDL/SDL_gfxPrimitives.h... (cached) yes
Checking for C++ header file SDL/SDL.h... (cached) yes
scons: done reading SConscript files.
scons: Building targets ...
g++ -o imglib/imgops.os -c -g -O3 -fPIC -Wall -D__warn_unused_result__=__far__ -g -fPIC -fPIC -I. -Icolib -Iimglib -Iimgio -Iimgbits -Iutils -Icomponents -Ividio imglib/imgops.cc
imglib/imgops.cc:136:40: error: redeclaration of 'template<class T, class V> void iulib::addscaled(colib::narray<T>&, colib::narray<T>&, V, int, int)' may not have default arguments [-fpermissive]
             V scale=1,int dx=0,int dy=0) {
                                        ^
In file included from ./colib/colib.h:55:0,
                 from imglib/imgops.cc:35:
./colib/debugf.h:30:10: warning: 'void {anonymous}::iprintf(FILE*, int, const char*, ...)' defined but not used [-Wunused-function]
     void iprintf(FILE *stream,int depth,const char *fmt,...) {
          ^
./colib/debugf.h:69:10: warning: 'void {anonymous}::debugf(const char*, const char*, ...)' defined but not used [-Wunused-function]
     void debugf(const char *which,const char *fmt,...) {
          ^
scons: *** [imglib/imgops.os] Error 1
scons: building terminated because of errors.

[MohamadIsmail]

You need to add default arguments in the header file "imgops.h" and remove them from the source file "imgops.cc" to avoid "redefinition of default argument" error.