How to change pictures settings...

To change picture settings just go to the Settings>Pictures menu.

Thumbnail:

You can set the width or height for the generated thumbnail. Or you can set both settings simulatheneosly by checking Crop image setting.

By entering File name Prefix or Suffix you can add some text before (Prefix) or after (Suffix) thumbnail's file name. For example if the prefix is pre and suffix is suff and filename is picture.jpg, target thumbnail will be pre_picture_suff.jpg

By editing Border and Border color settings you can set border size and color for the thumbnail.

Image quality is a setting for JPEG images only. It set JPEG quality of target thumbnails.

Original pictures:

Width and Height: You can set neither Width nor Height, and your pictures will have original size (they won't be resized). If you will set width size - program will automatically generate correct pictures with set width and correct proportions, and vice versa with height.

File name prefix and suffix are identical to Thumbnail settings.

By editing Border and Border color settings you can set border size and color for the picture.

Auto rename allow to make target pictures like picture01..2..3 (if you'll enter filemask picture)

Image quality is a setting for JPEG images only. It set JPEG quality of target pictures.