> if i use RTF thene image is not transfered to the result file.

In fact the images are there, but can only be displayed by MS Word (and may be some other viewers).

> I have tested to create the final result using “wordpad” and the result file size is 70KB.

It can also be, Wordpad downscales the image with a detailization loss. But we’ll check the RTF spec if there are compression options for such images available, supported by the major viewers.