[TYPO3-english] image properties when editing content: only administrator is able to change width, height etc

[Howard K]

hello,
using typo3 4.2 (actually WEC install)

as admin, i can insert image and manage properties such as
width,height, click to enlarge ...
however, 'lesser' users can only insert the image without being able to edit it.

where should i look / what documents should i read in order to enable
image editing by basic users?

tia