Thread: Images

Greetings,I'm working for the computer vision group at UMass's CS department and we are looking 
at using Postgres to catalog Images and video for a large data coordination project.  I am 
running my own experiments, but I wanted to know if anyone has any data on internally stored 
versus externally stored images.Collin Lynch.

We have a commercial media management system in development
(close to finished) using postgresql running under Linux written in Java.

Our philosophy has been to store the media as a file and just have
the pathname to the media item in the database. While I like the
theoretical side of storing media in the database and I am sure that
is how things will be done years ahead, the reality is that there are
many utility type programs (such as imagemagik for us) that can do
lots of things with media, but they all make today's assumption that
the data is available in a file. If, for example, you want to convert an
image from one format to another, if the content is in the database,
first you'd have to extract it into a file, then convert it and them
(probably)
put it back again. It creates a lot of work.

Just my 0.02.

What is the scope and timetable of your project? We might be
interested in donating to your project if it fits the non-profit
model, though our product is not open source.

>
> Greetings,
> I'm working for the computer vision group at UMass's CS department and we
are looking
> at using Postgres to catalog Images and video for a large data
coordination project.  I am
> running my own experiments, but I wanted to know if anyone has any data on
internally stored
> versus externally stored images.
>
> Collin Lynch.
>

Collin,

We have a document system that has approx 270,000 tif images. These can
be quite large (500k is not uncommon I think we now have over 50gb of
images).  We keep these out of the dbms and in separate files (dbms just
has filename) for several reasons.

1. We can have the same image in multiple formats if required.

2. We can distribute the images and dbms onto different disks or even
different servers (ie clients get data from one server and images from
another). In our latest multi-tier application again we get better speed
by accessing the images and data from different servers.

3. If the db is not available at least the images can be viewed (NB as
we are currently forced to run a db on a Windows NT server this is sadly
the case far too often).

4. We are able to cache/mirror the images around the wan so that users
pick images up from a more local copy reducing bandwidth requirements

5. Backing up is simpler as the database is much smaller and the images
are readonly

6. We can have multiple dbms and/or applications easily accessing the
images if required.

"Collin F. Lynch" wrote:
> 
>         Greetings,
>         I'm working for the computer vision group at UMass's CS department and we are looking
> at using Postgres to catalog Images and video for a large data coordination project.  I am
> running my own experiments, but I wanted to know if anyone has any data on internally stored
> versus externally stored images.
> 
>         Collin Lynch.

-- 
David Warnock
Sundayta Ltd