To Convert Direcotry of PDF files to a directory of JPG images.  

To Convert Direcotry of Images ( JPG,JPEG,PNG,BMP,PBM,PGM,PPM,XBM )  to a directory of any other images  ( JPG,JPEG,PNG,BMP,PBM,PGM,PPM,XBM ), which can change the size for all of them. using C++ and QT Library.