Welcome to the Apple Discussions.
I understand my mistake was to import the photos in iPhoto without first moving them to My Pictures.
It wasn’t, unless you’re running a Referenced Library. Are you?
Then I deleted all photos from the camera
You can probably recover the photos from your camera card with an app like
MediaRecover.
Today I open iPhoto and I don't find the photos any more : neither in iPhoto nor in My Pictures.
Are you sure you don’t have a damaged database file?
Option 1
Back Up and try rebuild the library: hold down the apple and option (or alt) keys while launching iPhoto. Use the resulting dialogue to rebuild. Choose to Rebuild iPhoto Library Database from automatic backup.
If that fails:
Option 2
Download iPhoto Library Manager and use its rebuild function. This will create a new library based on data in the albumdata.xml file. Not everything will be brought over - no slideshows, books or calendars, for instance - but it should get all your albums and keywords, faces and places back.
Because this process creates an entirely new library and leaves your old one untouched, it is non-destructive, and if you're not happy with the results you can simply return to your old one.
photo.002723.ipmeta
These are database files of about 4kb each. They are not your photos and your pics cannot be recovered from them.
Regards
TD