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().