Is it better to read and list images directly from file system using simple php, or is it better to store image meta info and filename in the database and access the images by doing a mysql select. What are the pros and cons of both solutions.
Listing files on a file system is probably the easiest way to accomplish what you trying to do but it's going to be very slow if you are trying to cycle through several thousand directories/files on a networked file system (NFS, CIFS, GlusterFS, etc).
Storing files in a database will create a much more overhead since you are now involving an external application to store information. You have to remember that every time you are using a database you are also using network I/O, authentication mechanism, query parser, etc. At the same time all of this overhead might provide for a faster response then using a networked file system.
To conclude - everything depends on amount of files you are working with and underlying infrastructure. Two major things to look out for are going to be disk I/O and network I/O.
People find it easier to store their files within folders and parse that folder with php. If you go the database method the database eventually gets larger and larger and larger.
I can see it becoming personal preference, but I personally have gone with parsing folders for images rather than storing it within a database.
Depends on the scale of what you are doing.
I would do the following:
This is what I would be doing.