Photo : 480*640 pixels size < 50 Kb
Signature : 560*160 pixels size< 50 Kb
Pdf documents: Size less than 300 kb
view the video below for how to resize the image size using paint.
For this you should have Adobe Pdf (or any other pdf software) reader in computer. First reduce the size of the scanned community certificate and eligibility certificate below 300kb. Now right click on the image and click convert into pdf.