Image uploading

When trying to upload an image from the ‘create new post’ page I get the following error:
Warning: move_uploaded_file(): open_basedir restriction in effect. File(/public_html/pictorialis/wp-admin/upload/050704telegraphpole.jpg) is not within the allowed path(s): (/home/merialc:/usr/lib/php:/usr/local/lib/php:/tmp) in /home/merialc/public_html/pictorialis/wp-admin/post.php on line 191
Warning: Cannot modify header information – headers already sent by (output started at /home/merialc/public_html/pictorialis/wp-admin/post.php:191) in /home/merialc/public_html/pictorialis/wp-admin/post.php on line 345
Any ideas/suggestions as to why this is happening and how to fix it?
Thanks,
Clair