upload erorr when I upload big images

[allvip]

upload erorr:

fatal erorr:Allowed memory size of 20971520 bytes exhausted (try to allocate 9344 bytes) in /gallery/include/picmgmt.inc.php on line 437.

What can I do?I try to edit   picmgmt.inc.php on line 437,but I don't know how.
I can not edit php.ini because my host won't allow that.I have no php.ini in the host root and I can't installl it.The host won't aloow that.I can upload large images on my host with file manager or with filezilla(ftp) but not in my coppermine gallery 1.5.Why?I try batch upload,but when I wanted to move the images in albums it give me the same error.

I really want to have large images on my gallery.Please help.
Thanks.

[allvip]

my gallery:
http://allvip.us/gallery/index.php

[Αndré]

http://documentation.coppermine-gallery.net/en/upload_troubleshooting.htm#upload_error_messages_allowed_memory_size

[allvip]

thanks,but I want my users to be able to upload large images too.

[Αndré]

You could try to use ImageMagick instead of GD2, if your host provides it. http://documentation.coppermine-gallery.net/en/configuration.htm#admin_picture_thumb_advanced_resize_method

If ImageMagick is not available and you cannot increase the PHP memory limit, you'll have to move your gallery to a hosts that fits your needs.

[allvip]

Solution here:

1)No further photos can be added to an album - batch add and http upload fails:  http://forum.coppermine-gallery.net/index.php/topic,77929.0.html 

2) Fatal error: Allowed memory size of X bytes exhausted:  http://forum.coppermine-gallery.net/index.php/topic,76445.0.html