WebEasy will generate new image files with names like "sitename001001.jpg" or sitename001001.gif" under any of the following conditions:
- The original image file is not in GIF or JPG format.
- The image was resized, cropped, rotated, colorized or otherwise modified in WebEasy.
- The image is overlapping another item on the page and the site is built as standard HTML (as opposed to Dynamic HTML).
In the case of TIFF images for instance, a new JPG will be generated for every TIFF image that appears in the site. Even if the same TIFF is used on two different pages, you'll end up with two JPG files. If, however, you convert the TIFF to a JPG using e.g.: PhotoShop, then insert the JPG in your site instead of the TIFF, no new images will be generated by WebEasy - that one original file will be used every time it appears in the site (assuming you didn't resize it or modify it in any other fashion inside WebEasy).
GIFs will be generated instead of JPGs if the source image contains transparency.