Problem using Barcode

i tried to use the barcode but i got the following error message !

Has anyone also the same problem ? The system is installed on an Debian linux !

Fatal error : Uncaught Error: Call to undefined function imagettftext() in /opt/NetMake/v9/wwwroot/scriptcase/prod/third/barcodegen/class/BCGFont.php:45 Stack trace: #0 /opt/NetMake/v9/wwwroot/scriptcase/prod/third/barcodegen/class/BCGBarcode1D.php(82): BCGFont->setText(’’) #1 /opt/NetMake/v9/wwwroot/scriptcase/devel/class/page/nmPageFld.class.php(15948): BCGBarcode1D->setFont(Object(BCGFont)) #2 /opt/NetMake/v9/wwwroot/scriptcase/devel/class/page/nmPageFld.class.php(15715): nmPageFld->CreateImgCodeBar() #3 /opt/NetMake/v9/wwwroot/scriptcase/devel/class/page/nmPageFld.class.php(175): nmPageFld->nm_ajax() #4 /opt/NetMake/v9/wwwroot/scriptcase/devel/class/page/nmSite.class.php(95): nmPageFld->__construct() #5 /opt/NetMake/v9/wwwroot/scriptcase/devel/lib/php/base_ini.inc.php(1481): nmSite->Run() #6 [internal function]: unknown() #7 /opt/NetMake/v9/wwwroot/scriptcase/devel/lib/php/base_ini.inc.php(2): sg_load(‘F808233B4756C0B…’) #8 /opt/NetMake/v9/wwwroot/scriptcase/devel/iface/fld.php(25): include_once(’/opt/NetMake/v9…’) in /opt/NetMake/v9/wwwroot/scriptcase/prod/third/barcodegen/class/BCGFont.php on line 45