How to create additional thumbnails of custom size in nextgen gallery while uploading images? [closed]

Is there any way out to create additional thumbnails of custom size in nextgen gallery while uploading images?
For example I would like to create 3 thumbnails of size 25*30, 100*50, and 400*350 to display them in certain custom pages.Or can i add custom code to resize when image upload is triggered and if so where?

Make shure your theme function have

add_theme_support( 'post-thumbnails' );

to add a custom image size use

add_image_size( 'thumb-one', 25, 30 );

for more details have a looh here