Description
int 
jpeg2wbmp ( string jpegname, string wbmpname, int d_height, int d_width, int threshold )
     Converts the jpegname JPEG file
     to WBMP format, and saves it as wbmpname.
     With the d_height and
     d_width you specify the height
     and width of the destination image.
    
Note: JPEG support is only available if 
PHP was compiled against GD-1.8 or later.
Note: WBMP support is only available if 
PHP was compiled against GD-1.8 or later.
     See also png2wbmp().