Portable Document Format (PDF) is a suitable file format for course material.
1. For Existing PDF files: If you have PDF files & you want to reduce their size. Refers any one of the following links-
OR
2.https://www.pdfcompress.com/
OR
3.http://www.compress-pdf.co.uk/
Follow the steps and obtain the compressed PDF file.
2. Creating optimize PDF files:
(i) If you have power point (ppt) or doc file then you can save it to PDF format directly by save as option & choose file type PDF in Microsoft word software.
(ii) If you have course material in the form of images (suitable image format is JPG) then first compress all images. You can refer following link to compress JPG files.
Now refer
following methods to convert JPG to PDF
Online Method: Refer the link http://smallpdf.com/
Offline Method: Using Microsoft word (Insert all the images in Microsoft word and save it to PDF.)
Use
black and white images and text instead of color images for the best quality in
compression.